Can improper wiring actually cause a fire?

In article <IdCfh.3117$Ft4.1932@trnddc02>, "resrfglc" <[email protected]> wrote:
>My sincere apologies to you and tofler. In my area, my 220 circuits (to
>stove, ac, Water healer all contain a neutral and a bare ground wire.

The stove needs it, because the control and lighting circuits are 120V, and
the 120V loads require a neutral.

The air conditioner probably does not, and the water heater almost certainly
does not, need or use a neutral.

And what exactly do you mean by "contain a neutral and a bare ground wire"? I
wouldn't be surprised if your water heater, for example, is wired with 10/2
with ground -- black, white, and bare. The white is *not* a neutral in that
case. It's supposed to be permanently re-identified to show that it's a hot
conductor, but many electricians never bother, and many inspectors don't
notice, or don't care.

>It seemed that this was done in accordance with the electrical codes in my
>area as the work was inspected by the City when the house was built.

It's never a Code violation to add unnecessary wires that aren't connected to
anything.
>
>Maybe "code" allows it in my area.

The NEC doesn't *prohibit* it anywhere. The dispute Toller and I have with you
is over your insistence that Code *requires* it -- which is complete nonsense.
>
>It seems to me that running a length of conductors to one's shop to operate
>a 220VAC device is an expense of time, energy and money that would warrant
>the (initially) redundant neutral given the minimal additional cost of the
>fourth conductor.

It's a *waste* of money. 240V devices do not need -- in fact, do not even
*use* -- a neutral conductor.
>
>My experience retrofitting homes and garages to serve new uses convinced me
>that one never knows how something may be used down the road.

If Toller installs a 3-wire 240V outlet (two hots and a ground), there is
absolutely no concern that "down the road" somebody else is going to try to
plug a load that requires a neutral into that receptacle -- the plug won't
fit.
>
>Oh, screw it. The OP is long out of the conversation and you guys are not so
>much interested in his issue as you are in winning.

I'm interested in seeing *accurate* information posted about electrical
wiring.
>
>You win.

In other words -- you actually read the Code for the first time...
>
>Wire it your way, I'll wire it my way.

Go right ahead. Nobody is stopping you -- it's your money you're wasting by
adding wires that are not used.

And as long as you're done insisting that the Code "requires" things that
anyone who has actually read it knows that it manifestly does not, then I'm
done telling you you're full of beans. Fair enough?

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

[email protected] wrote:

> That's kind of hard to do when the connections are inside of the
> wall, right?

You are in over your head sunshine, give it up.

Lew

I agree. They are not used because they are the best. They are used because
they are the least they can get away with.

"Mike" <[email protected]> wrote in message
news:[email protected]...
.
>
> They are pure unadulterated crap.
>
>
> --

On 14 Dec 2006 08:16:55 -0800, "bf" <[email protected]> wrote:

>But you're right, if done with care and common sense, wiring really
>isn't dangerous.

Until you plug it in....

then it deserves respect it is owed.
(120v does not hurt as much as the scrapes when you yank your hand out
of the chassis)

Mark
(sixoneeight) = 618

In article <[email protected]>, "bf" <[email protected]> wrote:

>No offense, but it is a common thing to see people overexaggerate the
>dangers of adding their own circuit, outlet, light, or whatever and
>call an electrician for even trivial things. It's not rocket science or
>as complex as some make it out to be.

No offense taken. You're right, it's not as complex as some make it out to be
(and I hope I haven't seemed to be in that category!) -- but just the same, it
isn't quite cut and dried, either. There *are* "gotchas" that can cause
trouble. The biggest danger, IMO, is not the amateur electricians who don't
know where the "gotchas" are -- it's the guys who don't even know that there
*are* any "gotchas".

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

Toller wrote:
> "Doug Miller" <[email protected]> wrote in message
> news:[email protected]...
> > In article <[email protected]>, "Toller"
> > <[email protected]> wrote:
> >>...
> >
> >>Given that, could doing anything improper actually result in a fire?
> > ...
> >
> > Improper connections with aluminum wiring is the biggie.
...
> >
> The aluminum wire and the inadequate overcurrent protection fall outside my
> conditions, ...

The conditions you stated were "doing anything improper".

I daresay that installing aluminum wiring, the same way
you would install copper, which is what is usually blamed for
the fire, meets that condition.

--

FF

Toller wrote:
> As you all know, a troll hijacked one of my posts and kept insisting that
> omitting a neutral on a pure 240v circuit would cause a fire, which would
> invalidate the insurance.
> But that brought up the question in my mind, can improper wiring actually
> cause a fire?

I don't know if it could cause a fire, but if you use a wire guage that
is too small, the wire will definitely get very hot. Obviously, if not
wired correctly, there's a possibility that the electricity can arc,
causing sparks which could ignite something.

But you're right, if done with care and common sense, wiring really
isn't dangerous.

Whohoo! I finally post to the wreck. My apologies in advance for the
googlegroups thing, the usenet server that I use doesnt allow posting,
and I'm too broke to afford a nice subscription to a decent server.

Anyways, My parents had a house built in 1997 (when I was 16 years
old). There have been two "near fire" incidents since it was built, on
120v circuits.

The first involved a pathetic "power strip" unit on the end of a
bar-style counter in the kitchen. The electrician installed this
pathetic plastic rail that was 14" long, and only containted two
outlets.One outlet would make intermittent contact, the other was fine.
One day in 1998, the unit started smoking a bit, the tripped the
breaker. I am quite a handyman, and amateur electronics technician, and
have had moderate experience with practical wiring, so I opened the
unit up to take a look at it. The bare ground wire had a nice crimped
plastic-insulated connector on it (in a matching beige color) and was
in fine shape. I don't know what the electrician did with the other two
plastic crimp-connectors (that I assume came with the unit) but he had
used wire nuts to connect the hot and neutral pigtails to their
respective wires (The outlet had pigtails, rather than screws or
backstabs). The wire nuts were a hair too large to fit into the plastic
rail, so he had taken a knife and trimmed the sides of the wirenuts
down. Over time, twisting plugs around inside the intermittent outlet
had caused the exposed metal edges of the wirenuts to brush against
each other, creating an arc between the hot and neutral lines. This
make some good smoke and melted the plastic rail housing a little bit.
(That same electrician installed lights in my father's woodshop with a
constant hot, a switched ground used as a neutral, and an un-connected
neutral, which we noticed and fixed before there was any noticable
problem.)

I replaced that mess with a plain old computer-style power-strip, with
the plug snipped off, and attached with good wirenuts and secured with
a big wad of electrical tape. It has been much more useful and
reliable, for the past 8 years.

The other incident was in the attic, which my parents decided to have
finished in 1999, into an "apartment style" space (with a bedroom,
kitchen, bathroom, and livingroom). I did the entirety of the
electrical wiring and electrical finish work, with the help of a BORG
how-to electrical code book, and some internet state-specific
electrical code research. It was inspected by a county electrical
inspector, and passed.

A little over a year ago, (after I had gotten married and moved out) my
parents and little brother were watching a movie in the attic
family-room. My mother plugged a circulating-oil-heater into an outlet,
and a different outlet, behind a couch, started smoking. After
dissecting the situation, we found a good third of the blue plastic
outlet box had melted, and half of the outlet itself had disintegrated.
I had chained the outlets from that breaker together, and that outlet
had been the weak link in the chain. It had one cable running in from
the previous outlet, and another running on to the next outlet. I had
bent a hook in the ends of the wires and stacked the two hooks onto
each of the screws (I dont trust the backstab system). That was
acceptable according to the inspector. The small contact area between
the two neutral wires had not been a problem until that higher-current
heater was plugged in, at which point it had exceeded the
current-carrying capacity of a contact point with such small
dimensions. It proceeded to overheat, melt, arc and destroy stuff.
20/20 hindsight has helped me realize that it's a very good idea to
throw a wire-nut onto situations where there is more than one wire, and
run a single-wire pigtail out to the screw contact.

The damage was done to the side of the outlet box AWAY from the 2x4
stud, thankfully, partially due to my father's instruction to install
the outlets "upside down" so they didn't look like a smiley-face and
tempt small children. Had it happened on the hot lead, or had the
outlet been installed the other direction, we would most likely have
had a fire (according to several expert and experienced opinions).

So yes, it's quite possible for even minor wiring problems to cause
fires.

Spott

Toller wrote:
> As you all know, a troll hijacked one of my posts and kept insisting that
> omitting a neutral on a pure 240v circuit would cause a fire, which would
> invalidate the insurance.
> But that brought up the question in my mind, can improper wiring actually
> cause a fire?
>
> Presumably any fool is capable of using the right gauge cable and breaker
> for the current, terminating all cables in junction boxes, using a suitable
> cover on the boxes, and securing the cable so it won't rip out of the box.
> Given that, could doing anything improper actually result in a fire? Seems
> to me that errors will result in the circuit not working, or a problem occur
> in the (presumably) fire resistant boxes.
> Given those basics being done right; what errors would result in fires?
>
> (I suppose one example might come from my cottage. It has cable entering
> the back of a kitchen cabinet and then going up to, and across the top. A
> mouse chewed through the wire to get into the cabinet and short circuited
> it, inches away from a pile of paper napkins. Seeing what happened to the
> mouse, I have to think I was lucky it didn't catch the napkins on fire.
> Obviously the cable shouldn't have been in the cabinet.)

Doug Miller wrote:
> In article <[email protected]>, "bf" <[email protected]> wrote:
>
> >But you're right, if done with care and common sense, wiring really
> >isn't dangerous.
>
> I have to disagree with you on several counts.
>
> First, "common sense" unfortunately is not nearly as common as it should be.
>

I see your point.. but everything in life is dangerous if you don't
know what you're doing.
Driving a car, using a saw, cooking, and even walking across a parking
lot has some danger.
However, if someone gets a decent book explaining how to wire (or has
someone teach them),
wiring is not any more dangerous than many other activities.

You may know more of the finer details of wiring than I.. but again,
common sense says that you use a 20A recepticle on a 20A circuit.. Sure
you might be able to get away with mismatching sometimes, but someone
like me can just match the numbers and be safe. That way I don't have
to know the answers to all the questions you pose.

No offense, but it is a common thing to see people overexaggerate the
dangers of adding their own circuit, outlet, light, or whatever and
call an electrician for even trivial things. It's not rocket science or
as complex as some make it out to be.

Doug Houseman wrote:
>
> ...
>
> solder helps with the movement of DC power thru the wires. It actually
> can hinder the movement of AC since AC moves on the surface of the wire.
> ...

DC also moves on surface of the wire because the free electrons
all reside on the surface of a conductor. Solder can help by making
that surface continuous all around the circuit.

DC cannot 'jump' across a gap unless it arcs. AC can, which is
why 'blocking' capacitors prevent DC from flowing around an
AC circuit.

--

FF

Doug Miller wrote:
> In article <[email protected]>, simplfy markem, (sixoneeight)@hotmail wrote:
> >The only advantage to soldering house wiring is that expansion and
> >contraction of the wires will not loosen the connection.
>
> That's not an issue with properly made splices using wire nuts, either. If it
> were, the Code wouldn't permit them.
>

I think you are observing the difference between good enough and
really, really, good..

--

FF

Pop` wrote:
> [email protected] wrote:
> > Doug Houseman wrote:
> >>
> >> ...
> >>
> >> solder helps with the movement of DC power thru the wires. It
> >> actually can hinder the movement of AC since AC moves on the surface
> >> of the wire. ...
> >
> > DC also moves on surface of the wire because the free electrons
> > all reside on the surface of a conductor. Solder can help by making
> > that surface continuous all around the circuit.
> >
> > DC cannot 'jump' across a gap unless it arcs. AC can, which is
> > why 'blocking' capacitors prevent DC from flowing around an
> > AC circuit.
>
> WHAAAAATTTTT????!!!!!!
>
> Crawl back into your nice, warm, furry faraday cages! Or at least get a
> clue!
>
> Sorry; couldn't resists; must .. not .. feed .. the .. trolls.. must .. not
> .. ...

Your posted email address doesn't seem to work.

Would you care to email your comments to me?

--

FF

CW wrote:
> <[email protected]> wrote in message
> news:[email protected]...
> >
> > Doug Houseman wrote:
> > >
> > > ...
> > >
> > > solder helps with the movement of DC power thru the wires. It actually
> > > can hinder the movement of AC since AC moves on the surface of the wire.
> > > ...
> >
> > DC also moves on surface of the wire because the free electrons
> > all reside on the surface of a conductor. Solder can help by making
> > that surface continuous all around the circuit.
>
> Not at all. To see this, one only has to look at AC skin depth. As frequency
> decreases, skin depth increases. At 60Hz, skin depth is approximately 1/3",
> deeper than common wiring is in diameter.

Are we not discussing different aspects of the phenomenon?
Isn't skin depth the distance below the surface of the conductor
at which the electric field strength drops to some fraction of
what it is at the surface of the conductor?

That is not the location of the free electrons that carry the
current. They stay on the surface.

> >
> > DC cannot 'jump' across a gap unless it arcs. AC can, which is
> > why 'blocking' capacitors prevent DC from flowing around an
> > AC circuit.
>
> AC does not pass through a properly functioning capacitor. Current charges
> and discharges the plates, giving the appearance of electrons passing
> through the gap but at no time do they do so.

Agreed that the electrons per se do not jump across the capacitor.
But if you have alternating current on one side of the capacitor
you will also have alternating current on the other side. In that
(non?)sense the AC jumps across, though the actual electrons
do not.

--

FF

CW wrote:
> Backpedaling I see.
>
> <[email protected]> wrote in message
> news:[email protected]...
> >
> > CW wrote:
> > > <[email protected]> wrote in message
> > > news:[email protected]...
> > > >
> > > > Doug Houseman wrote:
> > > > >
> > > > > ...
> > > > >
> > > > > solder helps with the movement of DC power thru the wires. It
> actually
> > > > > can hinder the movement of AC since AC moves on the surface of the
> wire.
> > > > > ...
> > > >
> > > > DC also moves on surface of the wire because the free electrons
> > > > all reside on the surface of a conductor. Solder can help by making
> > > > that surface continuous all around the circuit.
> > >
> > > Not at all. To see this, one only has to look at AC skin depth. As
> frequency
> > > decreases, skin depth increases. At 60Hz, skin depth is approximately
> 1/3",
> > > deeper than common wiring is in diameter.
> >
> > Are we not discussing different aspects of the phenomenon?
> > Isn't skin depth the distance below the surface of the conductor
> > at which the electric field strength drops to some fraction of
> > what it is at the surface of the conductor?
> >
> > That is not the location of the free electrons that carry the
> > current. They stay on the surface.
> >
> > > >
> > > > DC cannot 'jump' across a gap unless it arcs. AC can, which is
> > > > why 'blocking' capacitors prevent DC from flowing around an
> > > > AC circuit.
> > >
> > > AC does not pass through a properly functioning capacitor. Current
> charges
> > > and discharges the plates, giving the appearance of electrons passing
> > > through the gap but at no time do they do so.
> >
> > Agreed that the electrons per se do not jump across the capacitor.
> > But if you have alternating current on one side of the capacitor
> > you will also have alternating current on the other side. In that
> > (non?)sense the AC jumps across, though the actual electrons
> > do not.
> >

No, I am not.

You, however, seem to be unclear on the concept of skin depth.

Skin depth is a measure of the depth to which the electric field
penetrates the material. It is not, as you seem to believe, the
depth at which the current flows.

IOW, you're wrong.


--

FF

Doug Miller wrote:
> In article <[email protected]
>, [email protected] wrote:
> >
> >You, however, seem to be unclear on the concept of skin depth.
> >
> >Skin depth is a measure of the depth to which the electric field
> >penetrates the material. It is not, as you seem to believe, the
> >depth at which the current flows.
>
> Speaking of unclear on the concept... an electric field is simply a field in
> which work is done on an electric charge -- IOW, where current flows.

In a force field the potential to do work is present, whether work
is actually being done or not. Surely you'll agree that the electric
field extends beyond the wire into the surrounding air where no
current flows.

You do not need current to have an electric field. Light is
an example. The skin depth for light is real small.

> >
> >IOW, you're wrong.
>
> You might want to grab yourself a high school physics text and [re]acquaint

Wikipedia has good articles on the subject.

> yourself with a few concepts before you so glibly assure CW that he's
> mistaken. First, it's *static* charge that resides on the surface of a
> conductor, *not* electric current. Second, the cloud of free electrons in a
> metal extends throughout it, rather than being confined to the surface.

OK, you got me there.

I wasn't familiar with the relationship between skin depth and
current density. The current density at the center of #12 wire
is almost 90% of that at the surface, right?

Last night I was thinking about this and remembered the
Hall effect. That would not be possible without current
passing through the conductor, rather than along the surface.

NOW, Mr CW can see me backpedaling.

>
> Finally, you might want to ask yourself why the NEC-permitted ampacity of
> conductors below about 4/0 is [roughly] proportional to their cross-sectional
> area, not their diameter.

The NEC tables make assumptions about heat-dissipation
to the environment and 4/0 down to #8 conductors are
typically multi-standed, both of which complicate the issue.

If we look at the DC resistances vs cross sectional areas
for #10 and smaller in the table here:

http://en.wikipedia.org/wiki/American_wire_gauge

We see that the resistance is inversely proportionate to the
the cross sectional area, confirming your point. In that
same range the NEC permitted ampacity goes up on a per/
cross-sectional area basis as the wire size goes down,
evidently because the larger surface to volume ratio
dissipates heat better.

How about closing an AC circuit through a capacitor?
Would you agree that the AC 'passes' through the capacitor
even though the electrons do not?

BTW, other than the description at the top of the page,
I don't see any difference between NEC 310-19 and
NEC 310-18 here:
http://www.houwire.com/products/technical/article310_18.html
http://www.houwire.com/products/technical/article310_19.html

Are those pages correct?

--

FF

Markem (sixoneeight) wrote:
> On Mon, 18 Dec 2006 16:42:00 GMT, [email protected] (Doug Miller)
> wrote:
>
> >Properly installed aluminum wiring is not hazardous.
>
> Given that most home owners do not know that it also must be
> maintained over "properly installed". ...

Could you summarize some of the maintenance issues?

Does anything need inspection and/or replacement more often
than copper wire?

--

FF

Bruce wrote:
> On Wed, 3 Jan 2007 12:49:12 -0700, [email protected] wrote
> (in article <[email protected]>):
>
> >
> > Markem (sixoneeight) wrote:
> >> On Mon, 18 Dec 2006 16:42:00 GMT, [email protected] (Doug Miller)
> >> wrote:
> >>
> >>> Properly installed aluminum wiring is not hazardous.
> >>
> >> Given that most home owners do not know that it also must be
> >> maintained over "properly installed". ...
> >
> > Could you summarize some of the maintenance issues?
> >
> > Does anything need inspection and/or replacement more often
> > than copper wire?
> >
> >
>
> Check connection tightness perodically. The wide thermal expansion properties
> makes Al wire tend to work itself loose after awhile. Also be ware of any
> connecting devices (wire nuts, screw lugs, etc.) that are not specifically
> rated for Al wire.

That's kind of hard to do when the connections are inside of the
wall, right?

--

FF

Doug Miller wrote:
> In article <[email protected]>, [email protected] wrote:
> >Bruce wrote:
> >> >> On Mon, 18 Dec 2006 16:42:00 GMT, [email protected] (Doug Miller)
> >> >> wrote:
> >> >>
> >> >>> Properly installed aluminum wiring is not hazardous.
> [...]
> >> Check connection tightness perodically.
> [...]
> >That's kind of hard to do when the connections are inside of the
> >wall, right?
> >
> That, in and of itself, is sufficient to exclude the installation from the
> category of "properly installed" wiring, whether aluminum or copper. The NEC
> requires all junctions to be readily accessible.
>

Aha, so is removing the cover plate and then removing the
switch or outlet from the box is readily accessible, tearing
out the wall is where the line is drawn.

I sure wish those boxes were bigger, or at least DEEPER.
I recently replaced a ground -fault breaker in a bathroom
and it was a PIA.

I'm willing to bet that the number of homes that get that
inspection ever, let alone periodically, is about nil.

In an earlier article (not sure if its part of this thread or an
earlier discussion, someone suggested that for copper
wire it was better to terminate it on the screw, rather
than using the clamp. I assume he was referring to
switches and outlets. I find that to be well-nigh
impossible with #12. Is it acceptable to use crimped
lugs, with two lugs on the same screw? Or is there
really no problem with what Leviton calls 'back' connections?

I emailed Houston Wire to tell them about the error
in their webpages. Thanks for checking.

--

FF

Doug Miller wrote:
> In article <[email protected]>, [email protected] wrote:
...
>
> I assume you mean a GFCI *outlet*... Deeper boxes do exist, and they're
> frequently used in new construction, particularly where GFCIs are required.
> >
> >
...
> >wire it was better to terminate it on the screw, rather
> >than using the clamp.
>
> True. It's *much* more secure.
>
> Note that for aluminum wire, the clamp isn't even an option: you *must* use
> the screw.

But (and I am asking this mostly for the lurkers) surely only with
a proper (rated for aluminum) terminator on the wire. You are NOT
allowed to use bare aluminum wire under a brass screw, that is
a sure fire (no pun intended) recipe for disaster, right?

>
> ... Grab
> it with the tip of a needlenose pliers and twist. Or use an electrician's
> stripper-crimper tool (e.g. Gardner-Bender GS-70) -- most have a hole about
> 1/8" in diameter in one of the jaws, specifically for making such hooks. Stick
> the wire through the hole, twist the tool 180 degrees, and voila! a perfect
> hook.

OK that'd work but then the heads of the screws would stand
proud and the fixture would not fit back in the box. The GFCI
(thank you) protects two 'downstream' circuits. Looks like
one of those larger boxes is called for. And for a fumble
fingers like myself, lugs.

>
> >Is it acceptable to use crimped
> >lugs, with two lugs on the same screw?
>
> Yes, if the lugs are rated for 120V *and* the device is rated for two lugs. Of
> course, you could use one wire in a lug as a pigtail, and wire-nut it to as
> many other wires as needed.

When I rewire my home, which is currently a bastard
mix of romex and knob and tube, I intend, wherever possible,
to avoid both 'pass through' and splices behind the outlets,
feeding them from separate junction boxes in the attic or
crawlspace.

It is downright scary to discover that turning the lights on in
my dining room causes an (unused) upstairs bedroom outlet
to become hot to the touch.

But, as Mr Hodgett so diplomatically suggests, I've a lot
to learn first.

--

FF

"Chris Friesen" <[email protected]> wrote in message
news:[email protected]...
> Doug Miller wrote:
>
> > - Why is it important that the equipment grounding conductor for a
circuit be
> > run in the same cable or raceway as the circuit conductors?
>
> You've got me on this one. If I have two PVC conduits going from the
> panel and put the hots in one and the ground in the other, and the
> equpment is grounded properly, I'm at a loss as to what could happen.
>
> > - Why is it OK to install a 20A receptacle on a 15A circuit, but not a
30A
> > receptacle on a 20A circuit?
>
> According to this
>
>
http://www.passandseymour.com/knowhowfaq/showquestions.cfm?faqcategory=Electrical%20Basics
>
> it's *not* okay to install a 20A receptacle on a 15A circuit.
>

It generally pays to refer to NEC rather than something less authoritative,
such as a vendor site.

--

-Mike-
[email protected]

Doug Miller wrote:

> - Why is it important that the equipment grounding conductor for a circuit be
> run in the same cable or raceway as the circuit conductors?

You've got me on this one. If I have two PVC conduits going from the
panel and put the hots in one and the ground in the other, and the
equpment is grounded properly, I'm at a loss as to what could happen.

> - Why is it OK to install a 20A receptacle on a 15A circuit, but not a 30A
> receptacle on a 20A circuit?

According to this

http://www.passandseymour.com/knowhowfaq/showquestions.cfm?faqcategory=Electrical%20Basics

it's *not* okay to install a 20A receptacle on a 15A circuit.

Chris

"cyrille de Brebisson" <[email protected]> wrote in message
news:[email protected]...
> hello,
>
> you can start by using 240V like all decent people (read, in the rest of
> the world (Japan except)) and significantly reduce your risk (with or
> without a neutral or ground).
> the main reason is ohm's law (U=RI) coupled with resistance law J=RI² and
> power law W=UI
> ie: if you divide the Voltage on a circuit by 2, you will need to increase
> your intensity by 2 and therefore, the energy wated in the conductors
> (read heat) (of fixed resistance) will multiply by 4.
> so, for the same 'product' with the same output power, your cables will
> heat 4 times more in 120V than in 240...
> so, 240 is much safter than 120V (at least when it comes to burning down
> your house)...
>
> cyrille

How many houses burn down in the U.S. because of this supposed wiring
"problem"? Since I believe most electrical fires are related to equipment
malfunctions, faulty junctions and connections ......in fact I've never
heard (I don't get out much<g>) of a house burning down from a over heated
wire that was properly executed and fuse protected. I'd expect lamps, cords
etc. to cause way more havoc than the "in the wall" wiring......fear
mongering has its place but can you back it up? Incidently does anyone know
why "we" chose 120 instead of 220 as the norm?................Rod

Hello! Hello! Earth Calling Edison and Volta!!!! Come in ???
"Doug Miller" <[email protected]> wrote in message
news:[email protected]...
> In article <[email protected]>, "cyrille de Brebisson"
> <[email protected]> wrote:
>>hello,
>>
>>you can start by using 240V like all decent people (read, in the rest of
>>the
>>world (Japan except)) and significantly reduce your risk (with or without
>>a
>>neutral or ground).
>>the main reason is ohm's law (U=RI) coupled with resistance law J=RI² and
>>power law W=UI
>>ie: if you divide the Voltage on a circuit by 2, you will need to increase
>>your intensity by 2 and therefore, the energy wated in the conductors
>>(read
>>heat) (of fixed resistance) will multiply by 4.
>>so, for the same 'product' with the same output power, your cables will
>>heat
>>4 times more in 120V than in 240...
>>so, 240 is much safter than 120V (at least when it comes to burning down
>>your house)...
>
> That's clearly nonsense -- 240 is far more dangerous than 120, both in its
> potential (pardon the pun) to electrocute, and to arc. The claim of
> reduced
> heating in the conductors is likewise nonsense: in a properly sized
> circuit,
> with proper overcurrent protection, heating in the conductors is
> insignificant
> regardless of voltage (i.e. if the conductors are getting hot, it's
> because
> they're too small for the load imposed).
>
> --
> Regards,
> Doug Miller (alphageek at milmac dot com)
>
> It's time to throw all their damned tea in the harbor again.

"resrfglc" <[email protected]> wrote in message
news:dqAhh.94$Iy5.42@trnddc01...
> "insurers insist that the houses be rewired "
>
> Funny, I was told insurers don't get involved in wiring to codes etc. on
> this very listserv.

You misunderstood....They said the insurance company won't deny a claim for
said wiring.....refusing to write a policy or canceling a policy is not the
same thing......I had a insurance company cancel my policy after insuring my
100yr old house for probably 50years (20years with me with never a
claim).... for not replacing my roof on their schedule instead of
mine....nearly dying, surgery, serious health issues and related financial
impacts etc. wasn't important to them at all<g>. I figure the company bean
counters decided humble "old houses" were not a market they were interested
in anymore......I had another company refuse a new policy based on a some
remaining knob & tube wiring in my attic.....Rod

[email protected] wrote:

> Aha, so is removing the cover plate and then removing the
> switch or outlet from the box is readily accessible, tearing
> out the wall is where the line is drawn.

Yep.

> I sure wish those boxes were bigger, or at least DEEPER.
> I recently replaced a ground -fault breaker in a bathroom
> and it was a PIA.

You can get deeper/bigger boxes, but they cost a lot more--far out of
proportion to the size increase.

Chris

Tue, Dec 12, 2006, 4:50am (EST+5) [email protected] (Toller) doth
burbleth:
As you all know, a troll hijacked one of my posts and kept insisting
that omitting a neutral on a pure 240v circuit would cause a fire, which
would invalidate the insurance. But that brought up the question in my
mind, can improper wiring actually cause a fire? <snip>

If a question was asked, how are we supposed to know if it's a
troll, or you?

Can improper wiring actually cause a fire? You sure you're not a
troll, hijacking this post? Last I knew, yes, improper wiring CAN
"actually" cause a fire. Seen it happen. Try using google once in
awhile.



JOAT
I am, therefore I think.

[email protected] wrote:
> Doug Houseman wrote:
>>
>> ...
>>
>> solder helps with the movement of DC power thru the wires. It
>> actually can hinder the movement of AC since AC moves on the surface
>> of the wire. ...
>
> DC also moves on surface of the wire because the free electrons
> all reside on the surface of a conductor. Solder can help by making
> that surface continuous all around the circuit.
>
> DC cannot 'jump' across a gap unless it arcs. AC can, which is
> why 'blocking' capacitors prevent DC from flowing around an
> AC circuit.

WHAAAAATTTTT????!!!!!!

Crawl back into your nice, warm, furry faraday cages! Or at least get a
clue!

Sorry; couldn't resists; must .. not .. feed .. the .. trolls.. must .. not
.. ...

On Tue, 12 Dec 2006 18:07:36 GMT, "resrfglc" <[email protected]>
wrote:

>My sincere apologies to you and tofler. In my area, my 220 circuits (to
>stove, ac, Water healer all contain a neutral and a bare ground wire.
>
>It seemed that this was done in accordance with the electrical codes in my
>area as the work was inspected by the City when the house was built.
>
>Maybe "code" allows it in my area.
>
>It seems to me that running a length of conductors to one's shop to operate
>a 220VAC device is an expense of time, energy and money that would warrant
>the (initially) redundant neutral given the minimal additional cost of the
>fourth conductor.
>
>My experience retrofitting homes and garages to serve new uses convinced me
>that one never knows how something may be used down the road.

One of the things you must keep in mind is what code is today vs what
code was yesterday, and even what it was the day before.

Your four wire 240V circuit to the stove is what is currently required
by the NEC. It's also required to a clothes dryer. But it wasn't so
long ago--perhaps within the last five years, certainly within the
last ten--that there was a code exception that permitted using the
bare ground as a neutral. In other words, using three wires as a feed.
In fact, when I remodeled the kitchen in my 30 year old house, I
pulled out the three wire range cord (which was permitted in 1973) and
pulled in a four wire for the new range.

In my laundry room, the water heater was fed with 10/2 (no
ground--also permitted in '73) and the dryer was fed with 10/2
(w/ground--again, okay in '73). I pulled the heater wire out entirely
and moved the 10/2 wg from the dryer over to the heater, then pulled a
brand new 10/3 for the dryer.

There are a couple of issues that seem to crop up regularly in these
electrical threads that seem to confuse a lot of people. One is that
folks as old as I am, especially if they worked in a hardware store
(as did I), don't automatically assume a ground wire when talking
about 10/2 or 12/3, even though that's the only way it's sold now.

Back in the day, if you wanted a ground wire with your two wire
non-metallic, you better have said, "with ground," because if you
didn't, you were SOL when you got home if you needed a ground wire.
Yes, it was sold both ways.

The other issue that confuses is what's needed electrically and what's
needed by code. 240V devices only "need" two wires to run. Period.
They are both hot--there's no such thing as a "neutral" when you're
talking about 240V. Now, the code requires (in most cases) a ground,
so practically speaking, the 240V device "needs" a three wire
circuit--not to run, but to meet code.

When it comes to devices like dryers and stoves, it's a similar story.
The old code (up to 97?) permitted a three wire circuit (6/2 wg
typically, for a stove; 10/2 wg typically, for a dryer). That was, as
Doug says, to permit 120V clocks, microprocessors, etc. to function.

The current code requires four wires to eliminate the congruence of
the grounded and grounding functions in one wire, which is not a good
idea.

Frankly, if people would start thinking of a neutral more as a return
path than as the same thing as a ground (which it is at the main load
center, and only at the main load center) we would be a lot better
off. A neutral carries current, a ground in a properly functioning
circuit does not.

That's why there's no "neutral" in a pure 240V device (like a motor).
both legs carry current. Just like in a 120V device, where both legs
carry current. It's just that in a 120V device, the one current
carrying leg is at the same potential as the ground. At 240V, they're
both above ground. A lot of people are confused by that.

Someone mentioned a heater needing a four wire circuit, but I think
that is inaccurate. There shouldn't be anything about a water heater
that needs a neutral connection. However, I don't have an NEC book at
hand to confirm that. You have to remember that not all 240V circuits
have the same purpose. As has been mentioned, a 240V motor circuit
doesn't need a neutral.

By the way, a water heater, of all things, would be the best device to
cite that doesn't need a ground. In most cases it's in the very path
of what the electrical service is bonded to in the first place. That's
why the two wire feed was not only sufficient but safe enough to pass
muster for many years. Probably the advent of CPVC plumbing brought
about the necessity of a separate ground.

Alright, I've said that enough different ways for everyone to have a
shot at grasping it. I hope it helps.

--
LRod

Master Woodbutcher and seasoned termite

Shamelessly whoring my website since 1999

http://www.woodbutcher.net

Proud participant of rec.woodworking since February, 1997

email addy de-spam-ified due to 1,000 spams per month.
If you can't figure out how to use it, I probably wouldn't
care to correspond with you anyway.

Here I look at a subject line to which the answer is, yes it can.
But then again so can "to code wiring".

Mark
(sixoneeight) = 618

"Doug Miller" <[email protected]> wrote in message
news:[email protected]...
> In article <[email protected]>, "Mike Marlow"
<[email protected]> wrote:
>
> >Hey Doug - I think that what he meant by "common sense" was the common
sense
> >to follow such things as electrical code, and not get all wrapped up in
> >"would-be-nice-if" scenarios. Keep it simple, apply the code, and use
> >common sense with code as your guide line.
>
> Well, perhaps so -- but do you spend much time at alt.home.repair?

Nope. I have to confess total ignorance of that group.

> Seems that
> a lot of people are unaware that there even *is* an electrical code. And
some
> of the posts in this thread should be more than ample to show that even
some
> folks who know that the Code exists, don't know nearly as much about what
it
> says than they think they do.
>

Unfortunately it seems that there are a lot of folks who know a code exists,
and then throw out the phrase "Code" as if to support their position, with
no real knowledge of what the code even says. I'm the first to admit that I
don't have every page of the NEC memorized and I ask from time to time, in
order to cover areas that I might not deal with on a regular basis, but I
have certainly seen enough of the aforementioned references to code by those
who clearly know nothing about what it says. Now *that* is dangerous.

--

-Mike-
[email protected]

"Mike" <[email protected]> wrote in message
news:[email protected]...
> On 14 Dec 2006 10:56:08 -0800, [email protected] wrote:
>
> > and attached with good wirenuts
>
> ROFLMAO
>
> Wirenut: Heap of crap half assed solution looking for a fire, bodge,
> commonly found in North American wiring installations.
>

And your problem with wire nuts is precisely what?

--

-Mike-
[email protected]

You didn't even get close with either statement. Want to try again?

<[email protected]> wrote in message
news:[email protected]...
> DC also moves on surface of the wire because the free electrons
> all reside on the surface of a conductor. Solder can help by making
> that surface continuous all around the circuit.
>
> DC cannot 'jump' across a gap unless it arcs. AC can, which is
> why 'blocking' capacitors prevent DC from flowing around an
> AC circuit.
>
> --
>
> FF
>

In article <[email protected]>,
Lew Hodgett <[email protected]> wrote:
>[email protected] wrote:
>
> > Lew? I didn't realize you were the OP. Anyway, here's a specific
> > example, tell me what you would use in the place of wire nuts:
> >
> > Ceiling junction box with light fixture attached, power coming directly
> > to the that box, with a switch loop going to a wall mounted switch.
> > Using regular NM (Romex) cabling.
> >
> > How would you connect the line neutral to the light fixture
> > neutral,the line hot to the switch loop, and the return from the
> > switch loop to the light fixture hot conductor?
>
>What you are describing is the classic application for which the wirenut
>was designed to solve.
>
>Namely, the joining of a solid conductor (Romex) and a stranded pigtail
>(the lighting fixture).
>
>It is not a particularly good long term connection; however, there are
>some conditions in this application that minimize future problems.
>
>1) There is very little chance of vibration impacting the wirenut
>termination.
>
>2) The load is probably 600 watts or less so long term heat build up as
>a result of a high resistance connection is minimized.
>
>About the only possible alternate to a wirenut that is economically
>viable would be a butt splice connector which would be totally dependent
>on being able to make a proper mechanical crimp on a solid conductor,
>something I'm not qualified to comment on, but would refer to the splice
>manufacturer.
>
>Lew
>
>
>

OK... Are you saying that you WOULD use a wirenut in this case? :)

--
Often wrong, never in doubt.

Larry Wasserman - Baltimore, Maryland - [email protected]

In article <[email protected]>,
Lew Hodgett <[email protected]> wrote:
>[email protected] wrote:
>
> > I'm curious about what you consider an acceptable alternative.
>
>
>Depends on the application and type of conductors involved.
>
>Lew

Lew? I didn't realize you were the OP. Anyway, here's a specific
example, tell me what you would use in the place of wire nuts:

Ceiling junction box with light fixture attached, power coming directly
to the that box, with a switch loop going to a wall mounted switch.
Using regular NM (Romex) cabling.

How would you connect the line neutral to the light fixture
neutral,the line hot to the switch loop, and the return from the
switch loop to the light fixture hot conductor?
--
When the game is over, the pawn and the king are returned to the same box.

Larry Wasserman - Baltimore Maryland - [email protected]

Solder and shrink tubing are considered less safe than wire nuts for power
wiring because they will both fail at relatively low elevated temperatures.
A wire nut will continue to hold the wires tightly together until the wires
get so hot that the insulation burns off of them. Wire nuts have been used
safely and successfully in the electrical industry for over 75 years. The
only place that I would not use them is in high vibration areas of machinery
as they will shake loose over time. Split nuts or crimped on ring lugs that
are bolted together and then heavily insulated with rubber tape followed by
a layer of plastic tape is the solution for these locations such as motor
connections, etc. Solder and shrink tubing is great for low current control
circuits, but not for power.

--
Charley


"Lew Hodgett" <[email protected]> wrote in message
news:[email protected]...
> [email protected] wrote:
>
>
> > OK... Are you saying that you WOULD use a wirenut in this case? :)
>
> If I was on the clock, probably.
>
> If it was for myself, probably not (I like solder and shrink tubing).
>
> Lew
>
>
>

On Wed, 3 Jan 2007 12:49:12 -0700, [email protected] wrote
(in article <[email protected]>):

>
> Markem (sixoneeight) wrote:
>> On Mon, 18 Dec 2006 16:42:00 GMT, [email protected] (Doug Miller)
>> wrote:
>>
>>> Properly installed aluminum wiring is not hazardous.
>>
>> Given that most home owners do not know that it also must be
>> maintained over "properly installed". ...
>
> Could you summarize some of the maintenance issues?
>
> Does anything need inspection and/or replacement more often
> than copper wire?
>
>

Check connection tightness perodically. The wide thermal expansion properties
makes Al wire tend to work itself loose after awhile. Also be ware of any
connecting devices (wire nuts, screw lugs, etc.) that are not specifically
rated for Al wire.

"resrfglc" <[email protected]> wrote in message
news:HW2gh.4458$LL4.1957@trnddc04...

> OK, let's get off this "You're Right, He's Wrong" track for a moment.
>

That's ok, but only up to the point where mis-information is being given.

> Let's say you call your County Electrical Code Inspector and tell him you
> want to run a 240VAC Circuit from your Main Breaker Box (say sixty-feet?)
> out to your Garage/Shop. what size conductors you should pull for a
(40AMP?)
> load and see what he recommends.
>
> My point being that, given that information, e.g. MAX 40AMP load @ 220VAC
> he's likely to suggest you pull the three conductors and the mechanical
> ground.

Your point is incorrect. You might want to try exactly what you propose and
see what your county inspector suggests.

>
> I agree he will, if pressed, allow that - if the circuit is dedicated to a
> water heater, for instance, that you only need pull the two conductors and
> the mechanical ground.

I think you are assuming too much with this position.

>
> And, of course, the same would apply were you to specify the circuit would
> be dedicated to a specific electrical motor.
>

Ok, so now we are back to the beginning of this thread. It seems you have
arrived at the same conclusion that your adversaries were at when this
started.

--

-Mike-
[email protected]

In article <[email protected]>, [email protected] wrote:
>Bruce wrote:
>> >> On Mon, 18 Dec 2006 16:42:00 GMT, [email protected] (Doug Miller)
>> >> wrote:
>> >>
>> >>> Properly installed aluminum wiring is not hazardous.
[...]
>> Check connection tightness perodically.
[...]
>That's kind of hard to do when the connections are inside of the
>wall, right?
>
That, in and of itself, is sufficient to exclude the installation from the
category of "properly installed" wiring, whether aluminum or copper. The NEC
requires all junctions to be readily accessible.


--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

In article <[email protected]>, "R. Pierce Butler" <[email protected]> wrote:
>[email protected] (Doug Miller) wrote in
>news:[email protected]:
>>
>> Second, a 240V supply consists of two hots and a *ground*. Not a
>> "neutral which ... is the ground." Neutral is not ground. They are not
>> the same. And there is no neutral in a [North American] 240V circuit.
>> Period.
>>
>
>Then why is neutral abnd ground in the CB box the same thing
>electrically? Both are uninsulated blocks bolted to the case of the CB
>box?

The purpose of the ground wire is to ensure that the metal chassis of any
device so equipped is always at the same potential as earth ground. If it were
not, any fault that might occur inside the equipment could cause the chassis
to become live; any human being touching that chassis could then provide an
alternate path to ground for the fault current. Current flows in the ground
wire *only* in the event of a fault. Under normal operation, it carries no
current.

The purpose of the neutral wire is to conduct current from whatever device is
using it, back to the service entrance panel and thence to the utility. Under
normal operation, there *is* current flowing in the neutral wire (except, as
noted previously, in the case of 240V circuits which don't have one).

The two are bonded together in the service entrance panel (note *not*not*not*
"the CB [circuit breaker] box" -- any subpanel is a "circuit breaker box", and
the two *must* be separate in a subpanel) to ensure that the neutral wire
remains at the same potential as true earth ground.

Also, FWIW, the neutral bus bar in a typical panel is in fact insulated from
the panel chassis, but also equipped with a bonding jumper of some sort that
bypasses the insulation and connects the bar to the chassis. If the panel is
used as service entrance equipment, the jumper remains in place. To use it as
a subpanel, the jumper is removed.


--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

On Sun, 17 Dec 2006 00:30:13 GMT, Lew Hodgett
<[email protected]> wrote:

>Mike wrote:
>
>> Wirenut: Heap of crap half assed solution looking for a fire, bodge,
>> commonly found in North American wiring installations.
>>
>>> And your problem with wire nuts is precisely what?
>>
>> Everything, I wouldn't even trust them on low voltage door bell wiring
>> let alone anything carrying mains voltage and current.
>>
>> They are pure unadulterated crap.
>
>
>You want an argument, change the subject.

You want a properly engineered electrical installation, emigrate :)


--

[email protected] writes:
>
>Bruce wrote:
>> On Wed, 3 Jan 2007 12:49:12 -0700, [email protected] wrote
>> (in article <[email protected]>):
>>
>> >
>> > Markem (sixoneeight) wrote:
>> >> On Mon, 18 Dec 2006 16:42:00 GMT, [email protected] (Doug Miller)
>> >> wrote:
>> >>
>> >>> Properly installed aluminum wiring is not hazardous.
>> >>
>> >> Given that most home owners do not know that it also must be
>> >> maintained over "properly installed". ...
>> >
>> > Could you summarize some of the maintenance issues?
>> >
>> > Does anything need inspection and/or replacement more often
>> > than copper wire?
>> >
>> >
>>
>> Check connection tightness perodically. The wide thermal expansion properties
>> makes Al wire tend to work itself loose after awhile. Also be ware of any
>> connecting devices (wire nuts, screw lugs, etc.) that are not specifically
>> rated for Al wire.
>
>That's kind of hard to do when the connections are inside of the
>wall, right?

NEC forbids connections that cannot be easily accessed. In this case, one must
pull the device and torque the connections to the correct value for Al Wire.

Of course, the device itself must be rated for AL or AL/CU.

scott

In article <[email protected]>, "Mike Marlow" <[email protected]> wrote:
>
>"Chris Friesen" <[email protected]> wrote in message
>news:[email protected]...
>>
>> According to this
>>
>http://www.passandseymour.com/knowhowfaq/showquestions.cfm?faqcategory=Electric
>al%20Basics
>>
>> it's *not* okay to install a 20A receptacle on a 15A circuit.
>
>It generally pays to refer to NEC rather than something less authoritative,
>such as a vendor site.
>
Both he, and Pass & Seymour, are right. I stated it backwards.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

<[email protected]> wrote in message
news:[email protected]...

> >
>
> Aha, so is removing the cover plate and then removing the
> switch or outlet from the box is readily accessible, tearing
> out the wall is where the line is drawn.

Sorry - don't understand what you're trying to say with the above.

>
> I sure wish those boxes were bigger, or at least DEEPER.
> I recently replaced a ground -fault breaker in a bathroom
> and it was a PIA.

That's a problem with existing wiring. It's common to find old wiring that
used shallower boxes and in fact those boxes do not meet code for upgrades
to today's devices. Every box has a capacity rating and every element - the
wire, the device have displacements. If you can't stuff the GFCI into the
box you simply have the wrong box, not a problem with the size of the GFCI.
It does become necessary to replace those old shallow boxes with proper
sized boxes. So in short - you're right, it's a PIA, but the relief comes
from a new box.

>
> I'm willing to bet that the number of homes that get that
> inspection ever, let alone periodically, is about nil.

I'd suggest that more wiring gets inspected than you might think. Agreed
that a lot of homeowner rework and add-on work does not get inspected, but
more new work in existing structures does indeed get inspected than you'd
guess.

>
> In an earlier article (not sure if its part of this thread or an
> earlier discussion, someone suggested that for copper
> wire it was better to terminate it on the screw, rather
> than using the clamp. I assume he was referring to
> switches and outlets. I find that to be well-nigh
> impossible with #12. Is it acceptable to use crimped
> lugs, with two lugs on the same screw? Or is there
> really no problem with what Leviton calls 'back' connections?

#12 terminates on the screws just fine. Strip it back, pre-curl the bare
wire, slide it around the screw and give it a squeeze with the needle nose
and tighten the screw. It's done every day and it's no big deal. It's not
even a little deal.

That said, a lot of GFCI outlets now come with a clamp on the back and
screws on the side. You can wire to the screw as you would a standard
outlet, or you can stab the wire into the back and tighten that same screw
to clamp down the wire. This is not the same as the old, cheap back
stabbers that have been discussed here. This is a real mechanical clamp
that holds.


--

-Mike-
[email protected]

On Wed, 13 Dec 2006 21:25:44 GMT, "Pop`" <[email protected]>
wrote:

>Tim Douglass wrote:
>> On Tue, 12 Dec 2006 04:50:26 GMT, "Toller" <[email protected]> wrote:
>>
>>> As you all know, a troll hijacked one of my posts and kept insisting
>>> that omitting a neutral on a pure 240v circuit would cause a fire,
>>> which would invalidate the insurance.
>>> But that brought up the question in my mind, can improper wiring
>>> actually cause a fire?
>>
>> Yes.
>>
>> See here for one example:
>>
>> http://www.douglassclan.com/ManufacturedHomeDanger.html
>
>Ouch! I stopped to read that page, thinking it might have something
>interesting or that I hadn't come across, and indeed, it did. The amount of
>misinformation there is large, especially with the assumed theories that
>were stated.
> I don't doubt your initial experience as I've seen it myself, but ... I
>think you exaggerated greatly and unfortunately made a lot of wrong guesses
>about what what and why.
> If you'd like some assistance in updating that page so it's accurate and
>usable as an FYI, I'm sure there are people here who would assist you in
>that endeavor, myself included. As it stands, it's a badly expressed
>example of a bad situation but your understanding of electricity is
>obviously lacking and in need of improvement.

Please elucidate. I am actually quite experienced with electricity and
understand home wiring very well, but I was attempting to explain the
issue in a "dumbed-down" way so that it would be clear to anyone
reading it. I haven't looked at that page since I put it up a couple
years ago, but it passed muster with a couple of electrical
contractors who are friends of mine.

If you have corrections I would really like to hear about them. Either
post them here or e-mail me.

Thanks.
--
"We need to make a sacrifice to the gods, find me a young virgin... oh, and bring something to kill"

Tim Douglass

http://www.DouglassClan.com

In article <hsegh.5632$yZ4.852@trnddc05>, "resrfglc" <[email protected]> wrote:
>"as long as there is no 120V load "
>
>My point, exactly.

Your "point" originally was that _even_in_the_absence_ of 120V loads, the
neutral wire was supposedly "required by code". It's not.

>The run, w/o he neutral, would be "dedicate" to 240VAC by your approach

Which was what the OP was describing -- and you told him he needed a neutral
too. He doesn't.

>while mine affords he flexibility to employ the run otherwise without
>re-wiring from the MAIN.

While true, that's a separate issue from whether he needs a neutral when he
does *not* have a 120V load.

[further red herring re: ground wire removed]

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

In article <[email protected]>, "Charley" <[email protected]> wrote:
>Solder and shrink tubing are considered less safe than wire nuts for power
>wiring because they will both fail at relatively low elevated temperatures.
>A wire nut will continue to hold the wires tightly together until the wires
>get so hot that the insulation burns off of them.

The insulation will burn off long before they get hot enough to melt solder,
too.

The shrink tubing would be a Code violation unless it's specifically listed
for use at the voltage and amperage of the circuit involved.

> Wire nuts have been used
>safely and successfully in the electrical industry for over 75 years.

Apparently not in the UK :-)

[snip]
>Solder and shrink tubing is great for low current control circuits, but not for power.

The National Electrical Code permits soldered joints, but requires them to be
both mechanically and electrically secure *without* the solder. Nothing wrong
with using solder in power wiring -- it just can't be the *only* thing holding
the junction together.


--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

In article <[email protected]>, "R. Pierce Butler" <[email protected]> wrote:
>"Toller" <[email protected]> wrote in
>news:[email protected]:
>
>> As you all know, a troll hijacked one of my posts and kept insisting
>> that omitting a neutral on a pure 240v circuit would cause a fire,
>> which would invalidate the insurance.
>
>
>What he said was absolutely 100% wrong. The neutral in a pure 220vac
>does nothing but serve as a safety ground in the rare event that
>something were to go wrong and will help keep one from being shocked.

Unfortunately, what you said is *also* absolutely 100% wrong. The neutral in a
pure 240V circuit does nothing. Period. It serves no purpose. There is nothing
to connect it to, and in fact in most cases it is omitted. The safety ground
is the equipment ground, the bare wire.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

In article <[email protected]>, "R. Pierce Butler" <[email protected]> wrote:
>[email protected] (Doug Miller) wrote in
>news:[email protected]:
>
>> In article <[email protected]>, "R. Pierce
>> Butler" <[email protected]> wrote:
>>>"Toller" <[email protected]> wrote in
>>>news:[email protected]:
>>>
>>>> As you all know, a troll hijacked one of my posts and kept insisting
>>>> that omitting a neutral on a pure 240v circuit would cause a fire,
>>>> which would invalidate the insurance.
>>>
>>>
>>>What he said was absolutely 100% wrong. The neutral in a pure 220vac
>>>does nothing but serve as a safety ground in the rare event that
>>>something were to go wrong and will help keep one from being shocked.
>>
>> Unfortunately, what you said is *also* absolutely 100% wrong. The
>> neutral in a pure 240V circuit does nothing. Period. It serves no
>> purpose. There is nothing to connect it to, and in fact in most cases
>> it is omitted. The safety ground is the equipment ground, the bare
>> wire.
>>
>
>But there was no mention of a ground wire. ALl that was mentioned was
>the two wires to supply the 220vac and the neutral which, in this case,
>is the ground.
>
Still 100% incorrect, in at least two respects.

First, the original post proposed using 10/2 romex cable, which consists of a
black, a white, and a bare wire -- which are two hots and a ground. The
'troll' to which Toller refers insisted, incorrectly, that the circuit also
needed a neutral in order to comply with Code; this is false.

Second, a 240V supply consists of two hots and a *ground*. Not a "neutral
which ... is the ground." Neutral is not ground. They are not the same. And
there is no neutral in a [North American] 240V circuit. Period.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

In article <IIAfh.8227$Q36.5885@trnddc08>, "resrfglc" <[email protected]> wrote:
>"insisting that omitting a neutral on a pure 240v circuit would cause a
>fire"
>
>A, now we understand why you are so incensed. You miss read my posts. I did
>not say that as you allege, above.

He wasn't the only one to draw that inference from your mistaken posts.
>
>As regards liability, I simply said that you could be held liable for a fire
>caused by improper wiring and that your insurer might well be off the hook
>if it was shown that you did so in violation of the codes or law in the
>area.

The wiring scheme into which you injected that red herring was in no wise
"improper", despite your repeated insistence that it is.
>
>The 10/2 vs. 10/3 argument made was that it would be prudent to install the
>later regardless the immediate plans for the use of the new 20VAC run.

You said "A missing neutral would be hard to disguise".

Toller responded, "But if code doesn't require it and it isn't connected to
anything..."

And you then said, "CODES DO REQUIRE IT."

The fact is that the NEC does NOT require it for 240V loads.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

"Rod & Betty Jo" <[email protected]> writes:
>
>"cyrille de Brebisson" <[email protected]> wrote in message
>news:[email protected]...
>> hello,
>>
>> you can start by using 240V like all decent people (read, in the rest of
>> the world (Japan except)) and significantly reduce your risk (with or
>> without a neutral or ground).
>> the main reason is ohm's law (U=RI) coupled with resistance law J=RI² and
>> power law W=UI
>> ie: if you divide the Voltage on a circuit by 2, you will need to increase
>> your intensity by 2 and therefore, the energy wated in the conductors
>> (read heat) (of fixed resistance) will multiply by 4.
>> so, for the same 'product' with the same output power, your cables will
>> heat 4 times more in 120V than in 240...
>> so, 240 is much safter than 120V (at least when it comes to burning down
>> your house)...
>>
>> cyrille
>
>How many houses burn down in the U.S. because of this supposed wiring
>"problem"? Since I believe most electrical fires are related to equipment
>malfunctions, faulty junctions and connections ......in fact I've never
>heard (I don't get out much<g>) of a house burning down from a over heated
>wire that was properly executed and fuse protected. I'd expect lamps, cords
>etc. to cause way more havoc than the "in the wall" wiring......fear
>mongering has its place but can you back it up? Incidently does anyone know
>why "we" chose 120 instead of 220 as the norm?................Rod
>
>

When "we" chose 120, there was no norm.

scott

"Doug Houseman" <[email protected]> wrote in message
news:[email protected]...
>
> solder helps with the movement of DC power thru the wires. It actually
> can hinder the movement of AC since AC moves on the surface of the wire.

At 60Hz, skin effect is not a consideration.

"10/3 was required by Code for a pure 240V circuit "


OK, let's get off this "You're Right, He's Wrong" track for a moment.

Let's say you call your County Electrical Code Inspector and tell him you
want to run a 240VAC Circuit from your Main Breaker Box (say sixty-feet?)
out to your Garage/Shop. what size conductors you should pull for a (40AMP?)
load and see what he recommends.

My point being that, given that information, e.g. MAX 40AMP load @ 220VAC
he's likely to suggest you pull the three conductors and the mechanical
ground.

I agree he will, if pressed, allow that - if the circuit is dedicated to a
water heater, for instance, that you only need pull the two conductors and
the mechanical ground.

And, of course, the same would apply were you to specify the circuit would
be dedicated to a specific electrical motor.




conductors
"Doug Miller" <[email protected]> wrote in message
news:[email protected]...
> In article <Nf_fh.6773$bj5.3077@trnddc07>, "resrfglc"
> <[email protected]> wrote:
>
>>I maintain that the advice/suggestion to use 10/3 (three conductors and
>>equipment ground) over the alternative 10/2 (two conductors and equipment
>>ground) would better serve the OP and most all of us save those who never
>>err nor fail to plan perfectly for the future.
>
> Nobody *ever* criticized anyone for suggesting that 10/3 might be a better
> choice.
>
> You still don't seem to have figured out that you were catching heat for
> your
> insistence that 10/3 was required by Code for a pure 240V circuit -- and,
> by
> the way, it's not "taking shots at" you to point out that a false
> statement
> you made is in fact false.
>
> --
> Regards,
> Doug Miller (alphageek at milmac dot com)
>
> It's time to throw all their damned tea in the harbor again.

"insisting that omitting a neutral on a pure 240v circuit would cause a
fire"

A, now we understand why you are so incensed. You miss read my posts. I did
not say that as you allege, above.

As regards liability, I simply said that you could be held liable for a fire
caused by improper wiring and that your insurer might well be off the hook
if it was shown that you did so in violation of the codes or law in the
area.

The 10/2 vs. 10/3 argument made was that it would be prudent to install the
later regardless the immediate plans for the use of the new 20VAC run.

You concatenated several posts into an argument not intended. My apologies
for getting you off track.

"Toller" <[email protected]> wrote in message
news:[email protected]...
> As you all know, a troll hijacked one of my posts and kept insisting that
> omitting a neutral on a pure 240v circuit would cause a fire, which would
> invalidate the insurance.
> But that brought up the question in my mind, can improper wiring actually
> cause a fire?
>
> Presumably any fool is capable of using the right gauge cable and breaker
> for the current, terminating all cables in junction boxes, using a
> suitable cover on the boxes, and securing the cable so it won't rip out of
> the box. Given that, could doing anything improper actually result in a
> fire? Seems to me that errors will result in the circuit not working, or
> a problem occur in the (presumably) fire resistant boxes.
> Given those basics being done right; what errors would result in fires?
>
> (I suppose one example might come from my cottage. It has cable entering
> the back of a kitchen cabinet and then going up to, and across the top. A
> mouse chewed through the wire to get into the cabinet and short circuited
> it, inches away from a pile of paper napkins. Seeing what happened to the
> mouse, I have to think I was lucky it didn't catch the napkins on fire.
> Obviously the cable shouldn't have been in the cabinet.)
>

My sincere apologies to you and tofler. In my area, my 220 circuits (to
stove, ac, Water healer all contain a neutral and a bare ground wire.

It seemed that this was done in accordance with the electrical codes in my
area as the work was inspected by the City when the house was built.

Maybe "code" allows it in my area.

It seems to me that running a length of conductors to one's shop to operate
a 220VAC device is an expense of time, energy and money that would warrant
the (initially) redundant neutral given the minimal additional cost of the
fourth conductor.

My experience retrofitting homes and garages to serve new uses convinced me
that one never knows how something may be used down the road.


Oh, screw it. The OP is long out of the conversation and you guys are not so
much interested in his issue as you are in winning.

You win.

Wire it your way, I'll wire it my way.


"Doug Miller" <[email protected]> wrote in message
news:[email protected]...
> In article <IIAfh.8227$Q36.5885@trnddc08>, "resrfglc"
> <[email protected]> wrote:
>>"insisting that omitting a neutral on a pure 240v circuit would cause a
>>fire"
>>
>>A, now we understand why you are so incensed. You miss read my posts. I
>>did
>>not say that as you allege, above.
>
> He wasn't the only one to draw that inference from your mistaken posts.
>>
>>As regards liability, I simply said that you could be held liable for a
>>fire
>>caused by improper wiring and that your insurer might well be off the hook
>>if it was shown that you did so in violation of the codes or law in the
>>area.
>
> The wiring scheme into which you injected that red herring was in no wise
> "improper", despite your repeated insistence that it is.
>>
>>The 10/2 vs. 10/3 argument made was that it would be prudent to install
>>the
>>later regardless the immediate plans for the use of the new 20VAC run.
>
> You said "A missing neutral would be hard to disguise".
>
> Toller responded, "But if code doesn't require it and it isn't connected
> to
> anything..."
>
> And you then said, "CODES DO REQUIRE IT."
>
> The fact is that the NEC does NOT require it for 240V loads.
>
> --
> Regards,
> Doug Miller (alphageek at milmac dot com)
>
> It's time to throw all their damned tea in the harbor again.

In article <[email protected]>, [email protected] wrote:
>
>Doug Miller wrote:
>> In article <[email protected]>,
> [email protected] wrote:
>....
>>
>> I assume you mean a GFCI *outlet*... Deeper boxes do exist, and they're
>> frequently used in new construction, particularly where GFCIs are required.
>> >
>> >
>....
>> >wire it was better to terminate it on the screw, rather
>> >than using the clamp.
>>
>> True. It's *much* more secure.
>>
>> Note that for aluminum wire, the clamp isn't even an option: you *must* use
>> the screw.
>
>But (and I am asking this mostly for the lurkers) surely only with
>a proper (rated for aluminum) terminator on the wire. You are NOT
>allowed to use bare aluminum wire under a brass screw, that is
>a sure fire (no pun intended) recipe for disaster, right?

Bare aluminum wire can be attached to any screw terminal that is rated for
aluminum wire. What that consists of specifically, I don't know. I don't seem
to have any CO/ALR-rated devices around; all my spares look to be Cu-only.

>> ... Grab
>> it with the tip of a needlenose pliers and twist. Or use an electrician's
>> stripper-crimper tool (e.g. Gardner-Bender GS-70) -- most have a hole about
>> 1/8" in diameter in one of the jaws, specifically for making such hooks. Stick
>> the wire through the hole, twist the tool 180 degrees, and voila! a perfect
>> hook.
>
>OK that'd work but then the heads of the screws would stand
>proud

Well, yes -- by the thickness of the wire. Big deal.

> and the fixture would not fit back in the box.

Of course it will; what are you talking about? Electricians do this all the
time. A standard receptacle box is 2" wide, and a 120V receptacle with wires
attached to screw terminals on each side is only about 1 3/8" outside
dimension from screw head to screw head.

>The GFCI
>(thank you) protects two 'downstream' circuits.

No, it doesn't.

Quite possibly it does protect two downstream *outlets*. <g>

> Looks like
>one of those larger boxes is called for. And for a fumble
>fingers like myself, lugs.

Just attach the wires to the screw terminals. It's easier and neater.
[...]

>When I rewire my home, which is currently a bastard
>mix of romex and knob and tube, I intend, wherever possible,
>to avoid both 'pass through' and splices behind the outlets,
>feeding them from separate junction boxes in the attic or
>crawlspace.

Do yourself a favor and get a book or two on residential wiring from the
library or from the Borg before you start.

>It is downright scary to discover that turning the lights on in
>my dining room causes an (unused) upstairs bedroom outlet
>to become hot to the touch.

I think I'd replace that outlet today -- and install the new one with
pigtails.

>But, as Mr Hodgett so diplomatically suggests, I've a lot
>to learn first.

It appears he may be right -- but it's not rocket science, either. You can
learn nearly everything you need to know by reading, and by asking questions
of those who know what they're doing. If you've ever followed other threads on
the Wreck dealing with electrical wiring, you probably have a sense of whose
advice you can trust [*], whose you should take with a grain of salt, and
whose you should disregard altogether.

[*] I'd place LRod in that category, and, if I might be so immodest, myself.
(I'm sure there are others here, too, and I don't mean to offend anyone
whom I have inadvertently failed to mention.) People that LRod and I have
disagreed with (or made sport of!) over electrical issues probably belong in
one of the latter two categories.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

In article <[email protected]>,
Doug Miller <[email protected]> wrote:
<...snipped...>
>The National Electrical Code permits soldered joints, but requires them to be
>both mechanically and electrically secure *without* the solder. Nothing wrong
>with using solder in power wiring -- it just can't be the *only* thing holding
>the junction together.

I'm being somewhat facetious here, but what exactly is the benefit of
adding the solder here?

--
Often wrong, never in doubt.

Larry Wasserman - Baltimore, Maryland - [email protected]

In article <[email protected]>, [email protected] wrote:
>
>Doug Miller wrote:
>> In article <[email protected]
>>, [email protected] wrote:
>> >
>> >You, however, seem to be unclear on the concept of skin depth.
>> >
>> >Skin depth is a measure of the depth to which the electric field
>> >penetrates the material. It is not, as you seem to believe, the
>> >depth at which the current flows.
>>
>> Speaking of unclear on the concept... an electric field is simply a field in
>> which work is done on an electric charge -- IOW, where current flows.
>
>In a force field the potential to do work is present, whether work
>is actually being done or not. Surely you'll agree that the electric
>field extends beyond the wire into the surrounding air where no
>current flows.

Yeah, I'll go along with that.
>
>You do not need current to have an electric field. Light is
>an example. The skin depth for light is real small.

>
>> >
>> >IOW, you're wrong.
>>
>> You might want to grab yourself a high school physics text and [re]acquaint
>
>Wikipedia has good articles on the subject.
>
>> yourself with a few concepts before you so glibly assure CW that he's
>> mistaken. First, it's *static* charge that resides on the surface of a
>> conductor, *not* electric current. Second, the cloud of free electrons in a
>> metal extends throughout it, rather than being confined to the surface.
>
>OK, you got me there.
>
>I wasn't familiar with the relationship between skin depth and
>current density. The current density at the center of #12 wire
>is almost 90% of that at the surface, right?

I haven't run the numbers, but that sounds about right, maybe on the low side,
even.
[snip]
>How about closing an AC circuit through a capacitor?
>Would you agree that the AC 'passes' through the capacitor
>even though the electrons do not?

In a sense, anyway -- but I think we're splitting hairs. Certainly if you
apply an alternating current to one side of a capacitor, you get an
alternating current out of the other side too.
>
>BTW, other than the description at the top of the page,
>I don't see any difference between NEC 310-19 and
>NEC 310-18 here:
>http://www.houwire.com/products/technical/article310_18.html
>http://www.houwire.com/products/technical/article310_19.html
>
>Are those pages correct?

I didn't check every entry, but the first one appears to be correct. The
second one is definitely *not* correct: they have erroneously reproduced
310.18 under the heading of 310.19. The two tables are in fact substantially
different.
>

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

In article <hsegh.5631$yZ4.4045@trnddc05>, "resrfglc" <[email protected]> wrote:
>"The standard U.S. household wiring design has two 120 volt "hot" wires and
>a neutral which is at ground potential. The two 120 volt wires are obtained
>by grounding the centertap of the transformer supplying the house so that
>when one hot wire is swinging positive with respect to ground, the other is
>swinging negative. This versatile design allows the use of either hot wire
>to supply the standard 120 volt household circuits. For higher power
>applications like clothes dryers, electric ranges, air conditioners, etc. ,
>both hot wires can be used to produce a 240 volt circuit."
>
>http://hyperphysics.phy-astr.gsu.edu/hbase/electric/hsehld.html
>
>Hah!

What do you mean, "Hah!" ??

Nobody has disputed what you quoted above. The *entire* dispute in this thread
has been over your uninformed, misinformed, erroneous insistence that the
neutral wire was required for a 240V circuit that had _no_ 120V loads.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

In article <T2Bfh.3648$LL4.1086@trnddc04>, "resrfglc" <[email protected]> wrote:
>Annually, over 40,000 fires are attributed to home electrical distribution
>systems.
[snip remainder]

How many of those 40,000 fires are due to having omitted neutrals from 240V
circuits that don't need them in the first place?

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

Now, that's a response worthy of such a list. And he didn't take a shot at
anyone in the process.

Just to clarify, my original intent (poorly done though it might have been)
was to refer to installing a 240VAC run to a shop. While the OP indicated it
was for a motor, my advice was to run a generic 240VAC run (thinking "down
the line" as it were) that would serve the intended initial purpose and
prove adaptable to others (run a 110VAC branch off, for instance) should
the need arise - saving a re-wiring (not always a "pull" as most folks (and
the OP indicated) use romex rather than individual conductors pulled through
EMT (or equivalent).

I maintain that the advice/suggestion to use 10/3 (three conductors and
equipment ground) over the alternative 10/2 (two conductors and equipment
ground) would better serve the OP and most all of us save those who never
err nor fail to plan perfectly for the future.

Or, for that matter, get confused by return path, ground, equipment grounds,
neutral vs. ground, grounding buss bars and so on and so forth. (my
category)


"LRod" <[email protected]> wrote in message
news:[email protected]...
> On Tue, 12 Dec 2006 18:07:36 GMT, "resrfglc" <[email protected]>
> wrote:
>
>>My sincere apologies to you and tofler. In my area, my 220 circuits (to
>>stove, ac, Water healer all contain a neutral and a bare ground wire.
>>
>>It seemed that this was done in accordance with the electrical codes in my
>>area as the work was inspected by the City when the house was built.
>>
>>Maybe "code" allows it in my area.
>>
>>It seems to me that running a length of conductors to one's shop to
>>operate
>>a 220VAC device is an expense of time, energy and money that would warrant
>>the (initially) redundant neutral given the minimal additional cost of the
>>fourth conductor.
>>
>>My experience retrofitting homes and garages to serve new uses convinced
>>me
>>that one never knows how something may be used down the road.
>
> One of the things you must keep in mind is what code is today vs what
> code was yesterday, and even what it was the day before.
>
> Your four wire 240V circuit to the stove is what is currently required
> by the NEC. It's also required to a clothes dryer. But it wasn't so
> long ago--perhaps within the last five years, certainly within the
> last ten--that there was a code exception that permitted using the
> bare ground as a neutral. In other words, using three wires as a feed.
> In fact, when I remodeled the kitchen in my 30 year old house, I
> pulled out the three wire range cord (which was permitted in 1973) and
> pulled in a four wire for the new range.
>
> In my laundry room, the water heater was fed with 10/2 (no
> ground--also permitted in '73) and the dryer was fed with 10/2
> (w/ground--again, okay in '73). I pulled the heater wire out entirely
> and moved the 10/2 wg from the dryer over to the heater, then pulled a
> brand new 10/3 for the dryer.
>
> There are a couple of issues that seem to crop up regularly in these
> electrical threads that seem to confuse a lot of people. One is that
> folks as old as I am, especially if they worked in a hardware store
> (as did I), don't automatically assume a ground wire when talking
> about 10/2 or 12/3, even though that's the only way it's sold now.
>
> Back in the day, if you wanted a ground wire with your two wire
> non-metallic, you better have said, "with ground," because if you
> didn't, you were SOL when you got home if you needed a ground wire.
> Yes, it was sold both ways.
>
> The other issue that confuses is what's needed electrically and what's
> needed by code. 240V devices only "need" two wires to run. Period.
> They are both hot--there's no such thing as a "neutral" when you're
> talking about 240V. Now, the code requires (in most cases) a ground,
> so practically speaking, the 240V device "needs" a three wire
> circuit--not to run, but to meet code.
>
> When it comes to devices like dryers and stoves, it's a similar story.
> The old code (up to 97?) permitted a three wire circuit (6/2 wg
> typically, for a stove; 10/2 wg typically, for a dryer). That was, as
> Doug says, to permit 120V clocks, microprocessors, etc. to function.
>
> The current code requires four wires to eliminate the congruence of
> the grounded and grounding functions in one wire, which is not a good
> idea.
>
> Frankly, if people would start thinking of a neutral more as a return
> path than as the same thing as a ground (which it is at the main load
> center, and only at the main load center) we would be a lot better
> off. A neutral carries current, a ground in a properly functioning
> circuit does not.
>
> That's why there's no "neutral" in a pure 240V device (like a motor).
> both legs carry current. Just like in a 120V device, where both legs
> carry current. It's just that in a 120V device, the one current
> carrying leg is at the same potential as the ground. At 240V, they're
> both above ground. A lot of people are confused by that.
>
> Someone mentioned a heater needing a four wire circuit, but I think
> that is inaccurate. There shouldn't be anything about a water heater
> that needs a neutral connection. However, I don't have an NEC book at
> hand to confirm that. You have to remember that not all 240V circuits
> have the same purpose. As has been mentioned, a 240V motor circuit
> doesn't need a neutral.
>
> By the way, a water heater, of all things, would be the best device to
> cite that doesn't need a ground. In most cases it's in the very path
> of what the electrical service is bonded to in the first place. That's
> why the two wire feed was not only sufficient but safe enough to pass
> muster for many years. Probably the advent of CPVC plumbing brought
> about the necessity of a separate ground.
>
> Alright, I've said that enough different ways for everyone to have a
> shot at grasping it. I hope it helps.
>
> --
> LRod
>
> Master Woodbutcher and seasoned termite
>
> Shamelessly whoring my website since 1999
>
> http://www.woodbutcher.net
>
> Proud participant of rec.woodworking since February, 1997
>
> email addy de-spam-ified due to 1,000 spams per month.
> If you can't figure out how to use it, I probably wouldn't
> care to correspond with you anyway.

In article <[email protected]>, "Toller" <[email protected]> wrote:
>As you all know, a troll hijacked one of my posts and kept insisting that
>omitting a neutral on a pure 240v circuit would cause a fire, which would
>invalidate the insurance.
>But that brought up the question in my mind, can improper wiring actually
>cause a fire?

Absolutely it can. Don't you ever read your local newspaper? It happens with
disturbing frequency.
>
>Presumably any fool is capable of using the right gauge cable and breaker
>for the current, terminating all cables in junction boxes, using a suitable
>cover on the boxes, and securing the cable so it won't rip out of the box.

That's an awfully big presumption, in my opinion, based on some of the stuff
I've seen by previous owners of every house I've lived in.

>Given that, could doing anything improper actually result in a fire? Seems
>to me that errors will result in the circuit not working, or a problem occur
>in the (presumably) fire resistant boxes.
>Given those basics being done right; what errors would result in fires?

Improper connections with aluminum wiring is the biggie. A fellow I used to
carpool with lived across the street from a subdivision that was built in the
70s, with all homes wired with aluminum. One morning when I came to pick him
up, I saw that one of the homes had clearly just had a massive fire; he told
me it was common in that subdivision -- that about one house a year burned,
all due to faulty wiring.

Inadequate overcurrent protection is another. Just last week, at Lowe's, I had
to explain to another customer why it was not a good idea to replace a 15A
breaker with a 20A. "But it keeps tripping...."

Backstabbed connections on receptacles and switches, that work loose over time
and spark.

Receptacles recessed too far into a combustible wall (e.g. wood paneling). Not
dangerous in and of itself, but when combined with one of the problems cited
above, it's a disaster waiting to happen.

Much more information here:
http://www.cpsc.gov/volstd/afci/AFCIFireTechnology.pdf

Note this excerpt:

There are two basic types of arcing faults – series and parallel. Series
arcing faults occur when the current-carrying path in series with the load is
unintentionally broken. Arcing may occur across the broken gap and create
localized heating. The magnitude of the current in a series arc is limited by
the load. The series arcing currents are typically well below the typical
circuit breaker’s ampacity rating (often referred to as handle rating)
and, therefore, would never trip the conventional circuit breaker either
thermally or magnetically. Series arcing can lead to overheating that can be
hazardous. Examples of conditions that may result in series arcing faults
include loose connections to a receptacle or a wire splice, a worn conductor
from over flexing of a cable, or a pinched cable in which the conductor has
been severed.

A parallel arcing fault occurs when there is an unintentional conducting path
between conductors of opposite polarity. Parallel arcing is only limited by
the available fault current of the source and the impedance of the fault. If
the fault is of low impedance, then the overcurrent device should open.
However, when the fault impedance is relatively high, there may be
insufficient energy to open the overcurrent device. This can cause arcing that
can propel particles of molten metal onto nearby combustibles. A short circuit
caused by an intermittent contact is one type of parallel arcing fault that
can create hazardous arcs. A line-to-ground arcing fault is another form of
parallel arcing fault and occurs when an ungrounded line conductor is faulted
to a metal enclosure or other metal structure in contact with a grounding
conductor. Examples of these are cords cut by furniture with a metal leg or
loose wires that contact a grounded surface.

Parallel arcing faults are known to develop in three stages: leakage,
tracking, and arcing. Leakage currents normally occur in every electrical
wiring system due to parasitic capacitance and resistance of the cable
insulation. Leakage current values below 0.5 mA are considered safe. If the
wiring is maintained in good condition, the wiring may be used safely for
several decades. However, when the wiring is subjected to moisture,
conductive dusts, salts, sunlight, excessive heat, or high-voltage lightning
strikes, the insulation can break down and conduct higher leakage currents. As
leakage current increases – undetected across the conduction path – the
surface can heat up and pyrolyze the insulation. This process, known as
tracking, produces carbon that generates more heat and progressively more
carbon. Although this process may continue for weeks, months, or longer
without incident, eventually, sustained arcing may occur.

Parallel arcing faults are generally considered more hazardous than series
arcing faults, since there is more energy associated with a parallel arcing
fault than a series arcing fault. Parallel arcing faults usually result in
peak currents above the handle rating of the conventional circuit breaker.
This may trip the circuit breaker magnetically, if the impedance of the fault
is low and the available fault current is sufficient. However, in many
instances, the available short-circuit (fault) current is not sufficient to
trip the circuit breaker instantaneously (magnetic trip). In addition, in many
instances, the fault may be intermittent, so the overcurrent will not be
sustained long enough to trip the conventional circuit breaker thermally.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

In article <[email protected]>,
Mike <[email protected]> wrote:
>On Fri, 15 Dec 2006 17:40:32 -0500, "Mike Marlow" <[email protected]>
>wrote:
>
>>
>>"Mike" <[email protected]> wrote in message
>>news:[email protected]...
>>> On 14 Dec 2006 10:56:08 -0800, [email protected] wrote:
>>>
>>> > and attached with good wirenuts
>>>
>>> ROFLMAO
>>>
>>> Wirenut: Heap of crap half assed solution looking for a fire, bodge,
>>> commonly found in North American wiring installations.
>>>
>>
>>And your problem with wire nuts is precisely what?
>
>Everything, I wouldn't even trust them on low voltage door bell wiring
>let alone anything carrying mains voltage and current.
>
>They are pure unadulterated crap.
>
>
>--

I'm curious about what you consider an acceptable alternative.

--
When the game is over, the pawn and the king are returned to the same box.

Larry Wasserman - Baltimore Maryland - [email protected]

[email protected] wrote:

> Lew? I didn't realize you were the OP. Anyway, here's a specific
> example, tell me what you would use in the place of wire nuts:
>
> Ceiling junction box with light fixture attached, power coming directly
> to the that box, with a switch loop going to a wall mounted switch.
> Using regular NM (Romex) cabling.
>
> How would you connect the line neutral to the light fixture
> neutral,the line hot to the switch loop, and the return from the
> switch loop to the light fixture hot conductor?

What you are describing is the classic application for which the wirenut
was designed to solve.

Namely, the joining of a solid conductor (Romex) and a stranded pigtail
(the lighting fixture).

It is not a particularly good long term connection; however, there are
some conditions in this application that minimize future problems.

1) There is very little chance of vibration impacting the wirenut
termination.

2) The load is probably 600 watts or less so long term heat build up as
a result of a high resistance connection is minimized.

About the only possible alternate to a wirenut that is economically
viable would be a butt splice connector which would be totally dependent
on being able to make a proper mechanical crimp on a solid conductor,
something I'm not qualified to comment on, but would refer to the splice
manufacturer.

Lew

In article <[email protected]>, Roy Smith <[email protected]> wrote:
>In article <[email protected]>,
> [email protected] (Doug Miller) wrote:
>
>> In article
>> <[email protected]>, Doug
>> Houseman <[email protected]> wrote:
>> >solder helps with the movement of DC power thru the wires. It actually
>> >can hinder the movement of AC since AC moves on the surface of the wire.
>>
>> I thought that effect occurred only at higher frequencies, in the
>> neighborhood
>> of 400Hz and up -- i.e. at 60Hz, AC is still moving mostly inside the
>> conductor. No?
>
>I just refreshed what I used to know about skin effect by reading the
>wikipedia article about it (http://en.wikipedia.org/wiki/Skin_effect). The
>executive summary is that for 60Hz, current flows in the outer 8mm of a
>conductor. This means that for a solid wire anything less than 16mm
>diameter (a bit heavier than 6/0 AWG), skin effect can be ignored. It's
>certainly a total non-issue for the sizes of wire likely to be found in
>your house.

Thanks -- that's kinda what I thought, but I wasn't sure I was remembering
that right.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

I have one of those testers and found the circuit to my microwave had the
hot an neutral reversed as I was trying to remove a broken bulb. I did NOZT
unplug the thing and caused a short across the bulb socket and ground (I
assume).

Instead of tripping the breaker downstairs, it fried the component board in
the Microwave. I suspect that, had the outlet been properly wired, the short
I caused would have tripped the breaker an I would have a working Microwave
after resetting it.

No way, now, to prove this suspicion, but I should have 1. unplugged the
damn thing and 2. rewired the outlet too.

I did re-wire the outlet before the warranty repair guy got there and I
didn't share the entire story with them when I called or when he was there.
So I can't report that the improperly wired outlet voided my warranty repair
(a new motherboard) and cost me a $300 Microwave. But I have my suspicions.



"Steve B" <[email protected]> wrote in message
news:[email protected]...
>
> "Toller" <[email protected]> wrote in message
> news:[email protected]...
>> As you all know, a troll hijacked one of my posts and kept insisting that
>> omitting a neutral on a pure 240v circuit would cause a fire, which would
>> invalidate the insurance.
>> But that brought up the question in my mind, can improper wiring actually
>> cause a fire?
>>
>> Presumably any fool is capable of using the right gauge cable and breaker
>> for the current, terminating all cables in junction boxes, using a
>> suitable cover on the boxes, and securing the cable so it won't rip out
>> of the box. Given that, could doing anything improper actually result in
>> a fire? Seems to me that errors will result in the circuit not working,
>> or a problem occur in the (presumably) fire resistant boxes.
>> Given those basics being done right; what errors would result in fires?
>>
>> (I suppose one example might come from my cottage. It has cable entering
>> the back of a kitchen cabinet and then going up to, and across the top.
>> A mouse chewed through the wire to get into the cabinet and short
>> circuited it, inches away from a pile of paper napkins. Seeing what
>> happened to the mouse, I have to think I was lucky it didn't catch the
>> napkins on fire. Obviously the cable shouldn't have been in the cabinet.)
> This is an experiment I suggest to everyone.
>
> Go to the store. Buy one of the testers you insert into a three pronged
> plug that has the three lights. It gives you three indicator lights that
> tell you if the circuit is wired correctly, or if the wires are not
> correct.
>
> It is absolutely amazing how many circuits are wired wrong. Both in homes
> and in commercial buildings. Wiring that was done by professionals.
>
> I cannot say from my limited experience with electrical circuits whether
> or not what you suggest can actually start a fire.
>
> I can say from experience as a safety inspector how absolutely amazing it
> is that so many circuits are wired incorrectly.
>
> Steve
>

Annually, over 40,000 fires are attributed to home electrical distribution
systems.

These fires result in more than 300 deaths and over 1,400 injuries each
year. Statistics

from 1992-1996 show level trends in each of these estimates with no
indications of

decline. In 1996, $680 million in property loss was attributed to home
electrical

distribution fires.1

Arcing faults are one of the major causes of electrical wiring fires.2 A
1994

insurance company survey of 660 electrical fires indicated that over 33% of
these fires

were from arcing conditions.3 This data is further supported in a report by
Smith and

McCoskrie4 that summarized the characteristics of 149 investigated
residential fires.

http://www.cpsc.gov/volstd/afci/AFCIFireTechnology.pdf



"Toller" <[email protected]> wrote in message
news:[email protected]...
> As you all know, a troll hijacked one of my posts and kept insisting that
> omitting a neutral on a pure 240v circuit would cause a fire, which would
> invalidate the insurance.
> But that brought up the question in my mind, can improper wiring actually
> cause a fire?
>
> Presumably any fool is capable of using the right gauge cable and breaker
> for the current, terminating all cables in junction boxes, using a
> suitable cover on the boxes, and securing the cable so it won't rip out of
> the box. Given that, could doing anything improper actually result in a
> fire? Seems to me that errors will result in the circuit not working, or
> a problem occur in the (presumably) fire resistant boxes.
> Given those basics being done right; what errors would result in fires?
>
> (I suppose one example might come from my cottage. It has cable entering
> the back of a kitchen cabinet and then going up to, and across the top. A
> mouse chewed through the wire to get into the cabinet and short circuited
> it, inches away from a pile of paper napkins. Seeing what happened to the
> mouse, I have to think I was lucky it didn't catch the napkins on fire.
> Obviously the cable shouldn't have been in the cabinet.)
>

In article <[email protected]>, Chris Friesen <[email protected]> wrote:
>Doug Miller wrote:
>
>> - Why is it important that the equipment grounding conductor for a circuit be
>> run in the same cable or raceway as the circuit conductors?
>
>You've got me on this one. If I have two PVC conduits going from the
>panel and put the hots in one and the ground in the other, and the
>equpment is grounded properly, I'm at a loss as to what could happen.

Google up a thread in alt.home.repair titled "Use two 12/2s for 240v?" -- the
topic was discussed starting about 18 posts deep in the thread.
>
>> - Why is it OK to install a 20A receptacle on a 15A circuit, but not a 30A
>> receptacle on a 20A circuit?
>
>According to this
>
>http://www.passandseymour.com/knowhowfaq/showquestions.cfm?faqcategory=Electric
>al%20Basics
>
>It's *not* okay to install a 20A receptacle on a 15A circuit.

My mistake -- sloppy typing and proofreading; I reversed the amperage numbers
in both halves. Thanks for the catch. Question should have read:

Why is it OK to install a 15A receptacle on a 20A circuit, but not a 20A
receptacle on a 30A circuit?

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

In article <[email protected]>, Renata <barskir@not_myrealbox.com> wrote:

>You'd be surprised. Just had an aquaintance, who's not an
>unintelligent fellow, say - what difference does it make if I put a
>15A receptacle on a 20A circuit.

Fact is, it *doesn't* make any difference. The NEC explicitly permits placing
15A receptacles on 20A circuits, with the only restriction being that if a 20A
circuit has only *one* receptacle, it must be a 20A receptacle.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

In article <[email protected]>, "Mike Marlow" <[email protected]> wrote:

>Hey Doug - I think that what he meant by "common sense" was the common sense
>to follow such things as electrical code, and not get all wrapped up in
>"would-be-nice-if" scenarios. Keep it simple, apply the code, and use
>common sense with code as your guide line.

Well, perhaps so -- but do you spend much time at alt.home.repair? Seems that
a lot of people are unaware that there even *is* an electrical code. And some
of the posts in this thread should be more than ample to show that even some
folks who know that the Code exists, don't know nearly as much about what it
says than they think they do.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

"Toller" <[email protected]> wrote in message
news:[email protected]...
> As you all know, a troll hijacked one of my posts and kept insisting that
> omitting a neutral on a pure 240v circuit would cause a fire, which would
> invalidate the insurance.
> But that brought up the question in my mind, can improper wiring actually
> cause a fire?
>
> Presumably any fool is capable of using the right gauge cable and breaker
> for the current, terminating all cables in junction boxes, using a
> suitable cover on the boxes, and securing the cable so it won't rip out of
> the box. Given that, could doing anything improper actually result in a
> fire? Seems to me that errors will result in the circuit not working, or
> a problem occur in the (presumably) fire resistant boxes.
> Given those basics being done right; what errors would result in fires?
>
> (I suppose one example might come from my cottage. It has cable entering
> the back of a kitchen cabinet and then going up to, and across the top. A
> mouse chewed through the wire to get into the cabinet and short circuited
> it, inches away from a pile of paper napkins. Seeing what happened to the
> mouse, I have to think I was lucky it didn't catch the napkins on fire.
> Obviously the cable shouldn't have been in the cabinet.)
This is an experiment I suggest to everyone.

Go to the store. Buy one of the testers you insert into a three pronged
plug that has the three lights. It gives you three indicator lights that
tell you if the circuit is wired correctly, or if the wires are not correct.

It is absolutely amazing how many circuits are wired wrong. Both in homes
and in commercial buildings. Wiring that was done by professionals.

I cannot say from my limited experience with electrical circuits whether or
not what you suggest can actually start a fire.

I can say from experience as a safety inspector how absolutely amazing it is
that so many circuits are wired incorrectly.

Steve

In article <S2Bfh.3647$LL4.1369@trnddc04>, "resrfglc" <[email protected]> wrote:
>I have one of those testers and found the circuit to my microwave had the
>hot an neutral reversed as I was trying to remove a broken bulb. I did NOZT
>unplug the thing and caused a short across the bulb socket and ground (I
>assume).
>
>Instead of tripping the breaker downstairs, it fried the component board in
>the Microwave. I suspect that, had the outlet been properly wired, the short
>I caused would have tripped the breaker an I would have a working Microwave
>after resetting it.

If the outlet had been properly wired, the shell of the socket would have been
connected to the neutral conductor, instead of the hot. Bridging the neutral
to ground would not have tripped the breaker, since the two are at the same
potential anyway.


--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

"Toller" <[email protected]> wrote in
news:[email protected]:

> As you all know, a troll hijacked one of my posts and kept insisting
> that omitting a neutral on a pure 240v circuit would cause a fire,
> which would invalidate the insurance.


What he said was absolutely 100% wrong. The neutral in a pure 220vac
does nothing but serve as a safety ground in the rare event that
something were to go wrong and will help keep one from being shocked.


> But that brought up the question in my mind, can improper wiring
> actually cause a fire?
>

Sure.....anything can happen even in properly wired situations.


> Presumably any fool is capable of using the right gauge cable and
> breaker for the current, terminating all cables in junction boxes,
> using a suitable cover on the boxes, and securing the cable so it
> won't rip out of the box. Given that, could doing anything improper
> actually result in a fire? Seems to me that errors will result in the
> circuit not working, or a problem occur in the (presumably) fire
> resistant boxes. Given those basics being done right; what errors
> would result in fires?
>

Fires that started from electricty are generally due to a few factors. A
poorly made connection will causes things to heat up and get hot and
could eventually cause a fire. An piece of wire carrying too much current
will do the same thing.

> (I suppose one example might come from my cottage. It has cable
> entering the back of a kitchen cabinet and then going up to, and
> across the top. A mouse chewed through the wire to get into the
> cabinet and short circuited it, inches away from a pile of paper
> napkins. Seeing what happened to the mouse, I have to think I was
> lucky it didn't catch the napkins on fire. Obviously the cable
> shouldn't have been in the cabinet.)
>
>

That situation is one that could happen at any time. Romex is common in
walls, ceilings and attics...eveywhere a mouse is likely to be found.

There are no 100% safe electric wiring, devices, etc. There are
circumstances that can arise that will cause fire, death, injury, etc.

[email protected] (Doug Miller) wrote in
news:[email protected]:

> In article <T2Bfh.3648$LL4.1086@trnddc04>, "resrfglc"
> <[email protected]> wrote:
>>Annually, over 40,000 fires are attributed to home electrical
>>distribution systems.
> [snip remainder]
>
> How many of those 40,000 fires are due to having omitted neutrals from
> 240V circuits that don't need them in the first place?
>

exactly zero

[email protected] (Doug Miller) wrote in
news:[email protected]:

> In article <[email protected]>, "R. Pierce
> Butler" <[email protected]> wrote:
>>"Toller" <[email protected]> wrote in
>>news:[email protected]:
>>
>>> As you all know, a troll hijacked one of my posts and kept insisting
>>> that omitting a neutral on a pure 240v circuit would cause a fire,
>>> which would invalidate the insurance.
>>
>>
>>What he said was absolutely 100% wrong. The neutral in a pure 220vac
>>does nothing but serve as a safety ground in the rare event that
>>something were to go wrong and will help keep one from being shocked.
>
> Unfortunately, what you said is *also* absolutely 100% wrong. The
> neutral in a pure 240V circuit does nothing. Period. It serves no
> purpose. There is nothing to connect it to, and in fact in most cases
> it is omitted. The safety ground is the equipment ground, the bare
> wire.
>

But there was no mention of a ground wire. ALl that was mentioned was
the two wires to supply the 220vac and the neutral which, in this case,
is the ground.

Tim Douglass <[email protected]> wrote in
news:[email protected]:

> On Wed, 13 Dec 2006 21:25:44 GMT, "Pop`" <[email protected]>
> wrote:
>
>>Tim Douglass wrote:
>>> On Tue, 12 Dec 2006 04:50:26 GMT, "Toller" <[email protected]> wrote:
>>>
>>>> As you all know, a troll hijacked one of my posts and kept
>>>> insisting that omitting a neutral on a pure 240v circuit would
>>>> cause a fire, which would invalidate the insurance.
>>>> But that brought up the question in my mind, can improper wiring
>>>> actually cause a fire?
>>>
>>> Yes.
>>>
>>> See here for one example:
>>>
>>> http://www.douglassclan.com/ManufacturedHomeDanger.html
>>
>>Ouch! I stopped to read that page, thinking it might have something
>>interesting or that I hadn't come across, and indeed, it did. The
>>amount of misinformation there is large, especially with the assumed
>>theories that were stated.
>> I don't doubt your initial experience as I've seen it myself, but
>> ... I
>>think you exaggerated greatly and unfortunately made a lot of wrong
>>guesses about what what and why.
>> If you'd like some assistance in updating that page so it's
>> accurate and
>>usable as an FYI, I'm sure there are people here who would assist you
>>in that endeavor, myself included. As it stands, it's a badly
>>expressed example of a bad situation but your understanding of
>>electricity is obviously lacking and in need of improvement.
>
> Please elucidate. I am actually quite experienced with electricity and
> understand home wiring very well, but I was attempting to explain the
> issue in a "dumbed-down" way so that it would be clear to anyone
> reading it. I haven't looked at that page since I put it up a couple
> years ago, but it passed muster with a couple of electrical
> contractors who are friends of mine.
>
> If you have corrections I would really like to hear about them. Either
> post them here or e-mail me.
>
> Thanks.
> --
> "We need to make a sacrifice to the gods, find me a young virgin...
> oh, and bring something to kill"
>
> Tim Douglass
>
> http://www.DouglassClan.com
>



> Also note that the amount of electricity that can flow through a system
is controlled by the amount of resistance on the circuit, with the most
basic factor controlling resistance being the size of the wire. If we
shrink the wire two things happen; first, less power gets through, and
second, the wire heats up at that point.

You wrote this? This is really a 'dumbed down' start. I stopped reading
after the above. I'm sure you are experienced with electricity and
understand home wiring very well, but your explanation of it needs work.
No offense meant.
Hank

[email protected] (Doug Miller) wrote in
news:[email protected]:

> In article <[email protected]>, "R. Pierce
> Butler" <[email protected]> wrote:
>>[email protected] (Doug Miller) wrote in
>>news:[email protected]:
>>
>>> In article <[email protected]>, "R. Pierce
>>> Butler" <[email protected]> wrote:
>>>>"Toller" <[email protected]> wrote in
>>>>news:[email protected]:
>>>>
>>>>> As you all know, a troll hijacked one of my posts and kept
>>>>> insisting that omitting a neutral on a pure 240v circuit would
>>>>> cause a fire, which would invalidate the insurance.
>>>>
>>>>
>>>>What he said was absolutely 100% wrong. The neutral in a pure
>>>>220vac does nothing but serve as a safety ground in the rare event
>>>>that something were to go wrong and will help keep one from being
>>>>shocked.
>>>
>>> Unfortunately, what you said is *also* absolutely 100% wrong. The
>>> neutral in a pure 240V circuit does nothing. Period. It serves no
>>> purpose. There is nothing to connect it to, and in fact in most
>>> cases it is omitted. The safety ground is the equipment ground, the
>>> bare wire.
>>>
>>
>>But there was no mention of a ground wire. ALl that was mentioned was
>>the two wires to supply the 220vac and the neutral which, in this
>>case, is the ground.
>>
> Still 100% incorrect, in at least two respects.
>
> First, the original post proposed using 10/2 romex cable, which
> consists of a black, a white, and a bare wire -- which are two hots
> and a ground. The 'troll' to which Toller refers insisted,
> incorrectly, that the circuit also needed a neutral in order to comply
> with Code; this is false.
>
> Second, a 240V supply consists of two hots and a *ground*. Not a
> "neutral which ... is the ground." Neutral is not ground. They are not
> the same. And there is no neutral in a [North American] 240V circuit.
> Period.
>

Then why is neutral abnd ground in the CB box the same thing
electrically? Both are uninsulated blocks bolted to the case of the CB
box?

[email protected] (Doug Miller) wrote in
news:[email protected]:


> Also, FWIW, the neutral bus bar in a typical panel is in fact
> insulated from the panel chassis, but also equipped with a bonding
> jumper of some sort that bypasses the insulation and connects the bar
> to the chassis. If the panel is used as service entrance equipment,
> the jumper remains in place. To use it as a subpanel, the jumper is
> removed.
>
>

Not on my service entrance box aka CB box. The are both bolted to the
frame of the box and are uninsulated.

In article <[email protected]>, [email protected] wrote:
>Aha, so is removing the cover plate and then removing the
>switch or outlet from the box is readily accessible,

Absolutely.

> tearing out the wall is where the line is drawn.

Something to the effect of "without removing or damaging the structure or
finish of the building" is where the line is drawn. Tearing out the wall would
fall under that heading, but so would removing a piece of molding.
>
>I sure wish those boxes were bigger, or at least DEEPER.
>I recently replaced a ground -fault breaker in a bathroom
>and it was a PIA.

I assume you mean a GFCI *outlet*... Deeper boxes do exist, and they're
frequently used in new construction, particularly where GFCIs are required.
>
>I'm willing to bet that the number of homes that get that
>inspection ever, let alone periodically, is about nil.

I won't take that bet. :-)
>
>In an earlier article (not sure if its part of this thread or an
>earlier discussion, someone suggested that for copper
>wire it was better to terminate it on the screw, rather
>than using the clamp.

True. It's *much* more secure.

Note that for aluminum wire, the clamp isn't even an option: you *must* use
the screw.

> I assume he was referring to
>switches and outlets. I find that to be well-nigh
>impossible with #12.

Why? It's not that hard to bend a hook on the end of a #12 copper wire. Grab
it with the tip of a needlenose pliers and twist. Or use an electrician's
stripper-crimper tool (e.g. Gardner-Bender GS-70) -- most have a hole about
1/8" in diameter in one of the jaws, specifically for making such hooks. Stick
the wire through the hole, twist the tool 180 degrees, and voila! a perfect
hook.

>Is it acceptable to use crimped
>lugs, with two lugs on the same screw?

Yes, if the lugs are rated for 120V *and* the device is rated for two lugs. Of
course, you could use one wire in a lug as a pigtail, and wire-nut it to as
many other wires as needed.

> Or is there
>really no problem with what Leviton calls 'back' connections?

Yes, there really is a problem -- they're not nearly as secure as originally
believed. In fact, they're no longer listed for use with 14ga wire
specifically because of that. They don't always grab 12ga as tightly as they
should. Better to avoid them altogether, and just use the screws.
>
>I emailed Houston Wire to tell them about the error
>in their webpages. Thanks for checking.
>
No prob.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

"resrfglc" <[email protected]> wrote in message
news:hsegh.5631$yZ4.4045@trnddc05...
> "The standard U.S. household wiring design has two 120 volt "hot" wires
and
> a neutral which is at ground potential. The two 120 volt wires are
obtained
> by grounding the centertap of the transformer supplying the house so that
> when one hot wire is swinging positive with respect to ground, the other
is
> swinging negative. This versatile design allows the use of either hot wire
> to supply the standard 120 volt household circuits. For higher power
> applications like clothes dryers, electric ranges, air conditioners, etc.
,
> both hot wires can be used to produce a 240 volt circuit."
>
> http://hyperphysics.phy-astr.gsu.edu/hbase/electric/hsehld.html
>
> Hah!
>

Hah?????

--

-Mike-
[email protected]

On 15 Dec 2006 18:00:14 GMT, "J. Clarke" <[email protected]>
wrote:

>On Fri, 15 Dec 2006 16:33:08 +0000, Mike wrote:
>
>> On 14 Dec 2006 10:56:08 -0800, [email protected] wrote:
>>
>>> and attached with good wirenuts
>>
>> ROFLMAO
>>
>> Wirenut: Heap of crap half assed solution looking for a fire, bodge,
>> commonly found in North American wiring installations.
>
>Actaully, that "bodge" is required by the electrical code in US wiring,
>that or an equivalent.

So there is an equivalent to a wirenut is there? I'm having great
difficulty thinking of anything else that could "perform" a similar
"function" and be so badly engineered for the task in hand.

>Do you know of any cases in which wire nuts caused
>fires?

Google images "wire nut" and "wirenut" brings up quite a good
selection.

>What do _you_ use?

Fortunately I reside in the true land of the free where higher
standards are used in electrical installations. Basically just about
everywhere other than the USA.


--

In article <[email protected]>, "cyrille de Brebisson" <[email protected]> wrote:
>hello,
>
>you can start by using 240V like all decent people (read, in the rest of the
>world (Japan except)) and significantly reduce your risk (with or without a
>neutral or ground).
>the main reason is ohm's law (U=RI) coupled with resistance law J=RI² and
>power law W=UI
>ie: if you divide the Voltage on a circuit by 2, you will need to increase
>your intensity by 2 and therefore, the energy wated in the conductors (read
>heat) (of fixed resistance) will multiply by 4.
>so, for the same 'product' with the same output power, your cables will heat
>4 times more in 120V than in 240...
>so, 240 is much safter than 120V (at least when it comes to burning down
>your house)...

That's clearly nonsense -- 240 is far more dangerous than 120, both in its
potential (pardon the pun) to electrocute, and to arc. The claim of reduced
heating in the conductors is likewise nonsense: in a properly sized circuit,
with proper overcurrent protection, heating in the conductors is insignificant
regardless of voltage (i.e. if the conductors are getting hot, it's because
they're too small for the load imposed).

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

"Doug Miller" <[email protected]> wrote in message
news:[email protected]...
> In article <[email protected]>, "bf"
<[email protected]> wrote:
>
> >But you're right, if done with care and common sense, wiring really
> >isn't dangerous.
>
> I have to disagree with you on several counts.
>
> First, "common sense" unfortunately is not nearly as common as it should
be.
>
> Second, and more important, 120V and 240V alternating-current *is*
dangerous,
> at least potentially so: if mishandled, it can start fires, or
electrocute. To
> handle it "with care" requires a knowledge of the potential dangers, in
order
> to anticipate and avoid them. Far too many people decide to work on their
own
> wiring, lacking that knowledge -- and further lacking the awareness that
their
> knowledge is incomplete. Thinking they know what they're doing, they
create
> dangerous conditions unknowingly.

Hey Doug - I think that what he meant by "common sense" was the common sense
to follow such things as electrical code, and not get all wrapped up in
"would-be-nice-if" scenarios. Keep it simple, apply the code, and use
common sense with code as your guide line.

--

-Mike-
[email protected]

On Sun, 17 Dec 2006 04:30:41 -0600, "Henry St.Pierre"
<[email protected]> wrote:

>> Also note that the amount of electricity that can flow through a system
>is controlled by the amount of resistance on the circuit, with the most
>basic factor controlling resistance being the size of the wire. If we
>shrink the wire two things happen; first, less power gets through, and
>second, the wire heats up at that point.
>
>You wrote this? This is really a 'dumbed down' start. I stopped reading
>after the above. I'm sure you are experienced with electricity and
>understand home wiring very well, but your explanation of it needs work.
>No offense meant.
>Hank

I have no idea what I was trying to say there. I think I just mashed a
couple thoughts together. Like I said, this was done quickly.
Actually, the basic point there has to be something about smaller wire
getting hotter for a given load, which would relate to the small size
of the connector in the stab-in connection, which is what gets hot
under load. As a matter of fact, the use of stab-in connectors is
either banned or strongly discouraged in many areas now.

Re-reading that article there are a couple places I need to clean up.
--
"We need to make a sacrifice to the gods, find me a young virgin... oh, and bring something to kill"

Tim Douglass

http://www.DouglassClan.com

Backpedaling I see.

<[email protected]> wrote in message
news:[email protected]...
>
> CW wrote:
> > <[email protected]> wrote in message
> > news:[email protected]...
> > >
> > > Doug Houseman wrote:
> > > >
> > > > ...
> > > >
> > > > solder helps with the movement of DC power thru the wires. It
actually
> > > > can hinder the movement of AC since AC moves on the surface of the
wire.
> > > > ...
> > >
> > > DC also moves on surface of the wire because the free electrons
> > > all reside on the surface of a conductor. Solder can help by making
> > > that surface continuous all around the circuit.
> >
> > Not at all. To see this, one only has to look at AC skin depth. As
frequency
> > decreases, skin depth increases. At 60Hz, skin depth is approximately
1/3",
> > deeper than common wiring is in diameter.
>
> Are we not discussing different aspects of the phenomenon?
> Isn't skin depth the distance below the surface of the conductor
> at which the electric field strength drops to some fraction of
> what it is at the surface of the conductor?
>
> That is not the location of the free electrons that carry the
> current. They stay on the surface.
>
> > >
> > > DC cannot 'jump' across a gap unless it arcs. AC can, which is
> > > why 'blocking' capacitors prevent DC from flowing around an
> > > AC circuit.
> >
> > AC does not pass through a properly functioning capacitor. Current
charges
> > and discharges the plates, giving the appearance of electrons passing
> > through the gap but at no time do they do so.
>
> Agreed that the electrons per se do not jump across the capacitor.
> But if you have alternating current on one side of the capacitor
> you will also have alternating current on the other side. In that
> (non?)sense the AC jumps across, though the actual electrons
> do not.
>
> --
>
> FF
>

In article <HW2gh.4458$LL4.1957@trnddc04>, "resrfglc" <[email protected]> wrote:
>Let's say you call your County Electrical Code Inspector and tell him you
>want to run a 240VAC Circuit from your Main Breaker Box (say sixty-feet?)
>out to your Garage/Shop. what size conductors you should pull for a (40AMP?)
>load and see what he recommends.

And what does that have to do with whether Code requires a neutral or not?
>
>My point being that, given that information, e.g. MAX 40AMP load @ 220VAC
>he's likely to suggest you pull the three conductors and the mechanical
>ground.

He's more likely to first ask what kind of load it's serving. And when he
hears that it's a 240V motor, with no 120V loads, he's likely to suggest two
conductors plus equipment ground.
>
>I agree he will, if pressed, allow that - if the circuit is dedicated to a
>water heater, for instance, that you only need pull the two conductors and
>the mechanical ground.

If the circuit is serving 240V receptacles with no 120V loads, you only need
to pull two conductors and equipment ground.
>
>And, of course, the same would apply were you to specify the circuit would
>be dedicated to a specific electrical motor.

It doesn't have to be dedicated to *anything*. It can supply a 240V
receptacle, or several 240V receptacles, and as long as there is no 120V load
anywhere on the circuit, two conductors plus ground will be sufficient.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

Mike wrote:
> On Fri, 15 Dec 2006 17:40:32 -0500, "Mike Marlow" <[email protected]>
>
>>And your problem with wire nuts is precisely what?
>
>
> Everything, I wouldn't even trust them on low voltage door bell wiring
> let alone anything carrying mains voltage and current.
>
> They are pure unadulterated crap.
>
>

The National Electrical Code 110.14 state:

"Splices shall be made with an approved splice cap or “wire nut”."

What do you use in place of wire nuts?

--
Jack Novak
Buffalo, NY - USA
[email protected]

In article <[email protected]>,
[email protected] () wrote:

> In article <[email protected]>,
> Doug Miller <[email protected]> wrote:
> <...snipped...>
> >The National Electrical Code permits soldered joints, but requires them to
> >be
> >both mechanically and electrically secure *without* the solder. Nothing
> >wrong
> >with using solder in power wiring -- it just can't be the *only* thing
> >holding
> >the junction together.
>
> I'm being somewhat facetious here, but what exactly is the benefit of
> adding the solder here?

solder helps with the movement of DC power thru the wires. It actually
can hinder the movement of AC since AC moves on the surface of the wire.

If you do a good job with the wire nut (I highly recommend use of wire
nuts to join wires running AC power) then solder is not recommended in
any way. The use of Solder pre-dates the creation of wire nuts. I
typically find it in high end houses from the late 1930's to the early
1950's.

Normally because it is a dissimilar metal to the wire itself, there is
corrosion in the joint where it is used, when we take the joints apart.

"insurers insist that the houses be rewired "

Funny, I was told insurers don't get involved in wiring to codes etc. on
this very listserv.


"Markem" <markem(sixoneeight)@hotmail.com> wrote in message
news:[email protected]...
> On Mon, 18 Dec 2006 16:42:00 GMT, [email protected] (Doug Miller)
> wrote:
>
>>Properly installed aluminum wiring is not hazardous.
>
> Given that most home owners do not know that it also must be
> maintained over "properly installed". A subdivision in Schaumburg
> Illinois has an much high than average electrical fire problem due to
> "properly installed" aluminum wire, so much so that insurers insist
> that the houses be rewired with copper before a new owner can get
> insurance or a mortgage.
>
> It is hazardous to the bankers and insurance companies, and Cook
> county and Chicago no longer allow it for residences. But they still
> require conduit and wire nuts too.
>
> Chicago the most grounded city in the states.
>
> Mark
> (sixoneeight) = 618

In article <Nf_fh.6773$bj5.3077@trnddc07>, "resrfglc" <[email protected]> wrote:

>I maintain that the advice/suggestion to use 10/3 (three conductors and
>equipment ground) over the alternative 10/2 (two conductors and equipment
>ground) would better serve the OP and most all of us save those who never
>err nor fail to plan perfectly for the future.

Nobody *ever* criticized anyone for suggesting that 10/3 might be a better
choice.

You still don't seem to have figured out that you were catching heat for your
insistence that 10/3 was required by Code for a pure 240V circuit -- and, by
the way, it's not "taking shots at" you to point out that a false statement
you made is in fact false.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

On Thu, 14 Dec 2006 06:21:14 -0500, Joe Bemier wrote:

> On Thu, 14 Dec 2006 06:02:53 +0000, LRod <[email protected]>
> wrote:
>
>>On Thu, 14 Dec 2006 02:47:03 GMT, "resrfglc" <[email protected]>
>>wrote:
>>
>>>"10/3 was required by Code for a pure 240V circuit "
>>>
>>>
>>>OK, let's get off this "You're Right, He's Wrong" track for a moment.
>>>
>>>Let's say you call your County Electrical Code Inspector and tell him you
>>>want to run a 240VAC Circuit from your Main Breaker Box (say sixty-feet?)
>>>out to your Garage/Shop. what size conductors you should pull for a (40AMP?)
>>>load and see what he recommends.
>>
>>But that isn't enough information to give a definitive answer. As
>>Marisa Tomei said in "My Cousin Vinnie", "it's a bogus question."
>>
>>>My point being that, given that information, e.g. MAX 40AMP load @ 220VAC
>>>he's likely to suggest you pull the three conductors and the mechanical
>>>ground.
>>
>>I don't agree. Based on my foregoing, I believe your imaginary
>>inspector is going to ask the question you hint at below in order to
>>find which of two or possibly three correct answers he should give
>>you.
>>
>>>I agree he will, if pressed, allow that - if the circuit is dedicated to a
>>>water heater, for instance, that you only need pull the two conductors and
>>>the mechanical ground.
>>
>>The only pressing in the conversation will be him pressing you for
>>more information before he gives an answer, namely, what are you going
>>to run on the circuit?
>>
>>>And, of course, the same would apply were you to specify the circuit would
>>>be dedicated to a specific electrical motor.
>>
>>Which is exactly the kind of information he needs before he will ever
>>give you a definitive answer, because there isn't a definitive answer
>>without those parameters. That's what makes it a bogus question.
>>
>>And, by the way, if it's a county inspector, he's far more likely to
>>not really have that much interest, as opposed to a village, or worse,
>>city inspector.
>>
>>Finally, in addition to the fact that this is usenet and all answers
>>are suspect by definition, whatever anyone says here, even if it's
>>solid gold in the jurisdiction in which they live, there are places
>>that not only have more stringent requirements than those in the NEC,
>>but may not even base their own standards on it (Chicago is the
>>largest notable example of the latter, I'm told).
>
>
> Maybe this will help.....
>
> http://hyperphysics.phy-astr.gsu.edu/hbase/electric/hsehld.html

The trouble is that the Code is law and regulation, not physics.

--

--John

to email, dial "usenet" and validate

(was jclarke at eye bee em dot net)

On Fri, 15 Dec 2006 16:33:08 +0000, Mike wrote:

> On 14 Dec 2006 10:56:08 -0800, [email protected] wrote:
>
>> and attached with good wirenuts
>
> ROFLMAO
>
> Wirenut: Heap of crap half assed solution looking for a fire, bodge,
> commonly found in North American wiring installations.

Actaully, that "bodge" is required by the electrical code in US wiring,
that or an equivalent. Do you know of any cases in which wire nuts caused
fires? What do _you_ use?


--

--John

to email, dial "usenet" and validate

(was jclarke at eye bee em dot net)