Wiring a new shop

Chris Friesen wrote:
> Lew Hodgett wrote:
>
>> Chris Friesen wrote:
>> > What's the point of an insulated ground?
>>
>> It allows the entire distribution system to be grounded at the service
>> entrance point.
>>
>> Single point grounding eliminates "Ground Loops" which can be quite
>> nasty.
>
>
> I'm aware of ground loops. What does this have to do with an insulated
> ground bus in a subpanel?
>
> In my panel for instance, the ground bus is bonded to the panel, which
> is in turn grounded via a conductor going back to the main panel. As
> you mentioned, the entire system is grounded at the service entrance.
>
> Chris


The resulting ground loop (parallel neutral current paths) will allow
dangerous objectionable current to flow onto metal parts of the
electrical installation (and onto metal piping and structural steel).

Source: http://ecmweb.com/mag/electric_grounding_vs_bonding_5/index.html

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

On Jul 15, 8:50 pm, "Epictitus" <[email protected]> wrote:

>
> Plan where you are going to put your table saw and work table. If in the
> middle of the room then install a couple of 4" conduits into the floor.
>
What he said.
30 X 30 leaves a lot of space that's a long ways from a wall. Cords
hung from the ceiling get in the way more than you think. Put a
couple of runs of conduit under the slab with long-radius elbows and
couplings that are capped off flush with the floor. If the layout
changes, the conduit won't be a tripping hazzard. I ran flexible
conduit carrying both 220 and 110 from the floor fitting to my
tablesaw. The 110 is wired to a receptacle on my tablesaw extension
to run the router or whatever else I need out in the middle of the
floor. For the small investment in conduit, the payoff in safety and
convenience is big.

DonkeyHody
"In theory, theory and practice are the same, but in practice, they
are not."

On Jul 15, 4:42?pm, ed louie wrote:
Ed

Lots of nice information so far. So here comes mine.

I am in the sunbelt so am well insulated (12"), 12" walls and
ceiling. Steel studs and framing, Air Conditioned, no need for heat.
Shop temp rises 3 degrees on a 100 degree day with the air off.

Windows, (double pane) and door on the north side. Other 3 walls have
shelving from floor to ceiling. (Costco)

Electric is from main house panel. 60 Amp 220 volts and a 20 amp
emergency circuit should I trip any breakers on the subpanel in the
shop. Emergency circuit feeds a 20 amp outlet and a light which comes
on with loss of either side of the 60 amp 220 circuit.

Subpanel in the shop is a Square D 125 Amp panel that has 8 single
spaces or 16 ? spaces. Remember the neutral does not get grounded on a
subpanel. I also have a 10' ground rod for the ground at the shop.

I have my lathe, Air Compresser and AC on 220 circuits with 2 spare
220 breakers. All 220 is wired with #10 wire. All other wiring is #12.
I have 8 light switches in 2 metal boxes on the wall adjacent to the
door. Also a 12" X 12" electrical box for any spill over connections
that tend to clutter the subpanel. And a separate 4X4 box for the
emergency light and outlet. The box is large enough for the relay that
monitors the 220 legs from the house service panel.

All my 220 outlets are in the same box with a 110 outlet. All outlets
are the 20 amp type. 110 & 220. And all the outlet boxes are deep 4" X
4" metal boxes with mounting brackets that attach the boxes to steel
studs.

My Air Comprersser is 220 volts. I turn it on with its' breaker as
needed but intend to put in a relay that is controlled by the main
lighting switch. This will keep it from cycling when I am not in the
shop.

All my lighting is on 15 amp circuits. Everything else on 20 amp
circuits. Remember circuit breakers are for the protection of the
wiring only.

I have cable TV, phone, intercom, remote swithching for the AC and
anything else I can think of including an alarm and the outside light
so I can see in the dark coming and going. The shop is 10 feet below
the house. I can see the roof from the back porch. There are 2
condutits from the house. Power and everything else. 1?" and 1".
Should I have to do it over both would be 2".

Get everything you can on 220 volts. It will ease your electrical
problems. Don't buy cheap electrical outlets. Get the specification
grade at least. Buy wiring by the coil. 250' for # 10 and 500' for
#12.

My AC is the split type. The remote compressor/fan on the outside in
the shade and the coil and fan on the ceiling at the back of the 20 X
20 shop.

Hope this helps
Bob AZ

On Jul 16, 4:58?am, Frank Boettcher <[email protected]> wrote:
> On Sun, 15 Jul 2007 20:55:17 -0700, Bob AZ <[email protected]>
> wrote:
>
>
>
> >> I'm planning something similar.
>
> So you put a 60 amp breaker in the main (house) panel and ran a
> circuit to the subpanel. Did you pull the 125 main breaker from your
> subpanel and put a 60 amp main in the sub?
>
> what feed did you use. #4/3 wg Type SER or individual # 6 THWN wires
> in conduit with a # 10 ground? Or did you go oversize from the
> minimum required to carry 60 amps. Did you cost the difference
> between SER and conduit. Did you have to go underground or all above?
>
> Why the extra ground rod? Does the code require it? The sub ground
> bus is tied back to the main panel ground bus with the subpanel bonded
> to the ground bus but not strapped to the nuetral bus, I assume.
>
> FRank

Frank

The NEC allows a 60 amp feed from the house or another sub panel, to
feed directly to the additional subpanel buss without using a main
breaker in the additional subpanel. The 125 amp panel comes without a
main breaker. Home Depot.
I used #6 THHN wire. 2 hot legs, 1 neutral and a ground from the house
panel. #6 is oversize but I always go oversize on the feed to any
panel. This was an underground run, 85'.

The extra ground rod is not required by code. I did it for lightning
protection. I would lose lots of things without it since we have nasty
lightning every summer. The #6 ground back to the main panel is
required and would be wiped out ion a lightning strike every summer.
Thus the ground rod. There is no wire size that will take a lightning
strike of any intensity.

Where I live we have soil conditions such that one goes PVC conduit or
else. Even EMT conduit eventually disappears due to electrolysis. I
know it sounds funny but just this last week a friend had to start
replacing a service to his shop that was in EMT conduit. And direct
burial is nice but requires a 12" sand barrier. Thus PVC conduit is
the less exensive way to go. Costs a bit less and lasts forever. I
don't use Al wire at all. Too many longterm problems. The power
company has my house fed, underground, with AL and they will
eventually have to replace it. The neutral usually burns in two.
I knew PVC underground was cheaper and while the man was preparing my
site for the slab he just took another hour to dig the electric
trench. I had the conduit ready to drop in and he covered it up in
about 2 minutes with clean fill. We have lots of rocks that move
around a lot.
Under certain conditions the NEC requires a ground the size of the
current carrying conductors or larger. With what I know now I would go
even larger. It was not much more money. I probably spent less than
$100.00 for all the electric add ons. It is cheap insurance. And I had
less to worry about for all the other things like cable TV, intercom,
computer etc.

Take care
Bob AZ

On Jul 16, 7:04?am, Steve <[email protected]> wrote:
> Bob AZ wrote:
>
> > My AC is the split type. The remote compressor/fan on the outside in
> > the shade and the coil and fan on the ceiling at the back of the 20 X
> > 20 shop.
>
> What capacity AC unit did you get? Did you installl it yourself? What
> brand is it?
>
> Thanks!
>
> --Steve

Steve

2? ton split unit. Smallest split unit I could locate. Forgot the
brand. Only 13 SEER. Shop for the most SEER. I really pays off and the
higher SEER units are usually better built. I have a a friend now who
will find me what I want were I need to do it again.

I installed it myself and had the refrigerant lines soldered/done by a
AC technician. He does them everyday.Shop for what you want. It is out
there. I also made sure I got a 220 unit.

Bob AZ

On Jul 16,
>
> Better check that NEC. My understanding is if it is a completely
> separate building and has over six spaces it's required. But I never
> checked it, going by an article I read in Fine Hombuilding (April
> 2003)
>
> Frank-

The 60 Amp breaker feeding a subpanel is an exception according to the
city permit folks. I know the inspector checked the 60 amp thing. I
watched him do this.

But beware. Not all municipalities always follow all the code all the
time.

A little background. Goes something like this. Years ago when 50 amp
was a big panel they went to 100 amp. But the biggest branch circuit
breaker that would fit in the panel was 60 amp. So they allowed 60 amp
branch circuits to power a sub panel. And there was no max on the
subpanel as long as it was fed by a 60 amp breaker. Thus the provision
to allow a sub panel to be fed by a 60 amp breaker with no main in the
sub panel. So using a bigger subpanel gives some options for lots of
separate breakers/circuits in a shop like yours and mine.

Bob AZ

Mike Berger wrote:

> It's very common with metalworking machines.
<snip>

You must be new.

Trying to talk to Miller is like pissing up wind.

After a while, you know better.

Lew

Bob AZ wrote:

>
> My AC is the split type. The remote compressor/fan on the outside in
> the shade and the coil and fan on the ceiling at the back of the 20 X
> 20 shop.
>

What capacity AC unit did you get? Did you installl it yourself? What
brand is it?

Thanks!

--Steve

Lew Hodgett wrote:

Now I'm no pro, but it seems like some of these suggestions are overkill.

> Use 1P-20 c'bkrs for all 120V circuits of which at least 4 are dedicated
> to lighting.

Why? I could see two for safety, but four? And why bother making the
lighting circuits 20A, when they won't be drawing anywhere close to 15A?

> 240V circuits:
>
> Dedicate a 2P-50 for a 5HP air compressor

Sounds reasonable. I didn't in my small shop, but only because I don't
have room for a big compressor. I have a spare 30A circuit available
for a future compressor upgrade.

> 2P-30 for the balance.

This seems like overkill, since its generally only needed for 5HP
motors. Given the price of copper around here, I couldn't justify it.

> Run every thing you can at 240V, especially stationary tools like DC,
> TS, Jointer, dedicating an individual c'bkr for each load.

The individual circuits won't hurt, but it's probably overkill. In a
small shop the stationary tools likely won't ever run simultaneously
(and with only 60A supply, there isn't the juice for it anyways). It
makes sense to have DC and compressor on individual circuits, the rest
likely won't be an issue. I split mine over multiple circuits because I
had the cable, but its likely not necessary.

> Use 30A locking receptacles & plugs for 240V services.

This would require replacing the plugs on the tools. If you're using
overhead drops it makes sense, but for wall or floor I don't see major
benefits. I've never pulled out a cord accidentally on a stationary tool.

Chris

Bob AZ wrote:

>
> 2? ton split unit. Smallest split unit I could locate. Forgot the
> brand. Only 13 SEER. Shop for the most SEER. I really pays off and the
> higher SEER units are usually better built. I have a a friend now who
> will find me what I want were I need to do it again.

All the units I've found on-line are 13 SEER. I found one at 14 SEER
that's about $300 more than the others.

>
> I installed it myself and had the refrigerant lines soldered/done by a
> AC technician. He does them everyday.Shop for what you want. It is out
> there. I also made sure I got a 220 unit.

One on-line vendor claims it's illegal for someone who is not
EPA-certified to mess with refrigerants - is that true?

>
> Bob AZ
>

Lew Hodgett wrote:
> Frank Boettcher wrote:

> > Insulated ground bar means remove the strap to the nuetral if so
> > configured?
>
> NO, what you are describing is a bonding strap used to bond the neutral
> to the enclosure when the panel is used as a service entrance panel.
>
> An insulated ground bus is exactly that.
>
> It will look like the neutral bus but be insulated from the panel.
>
> An electrical distributer will have them as a kit.


At least in my circumstance the subpanel did not use an insulated
ground. The bonding screw was removed from the neutral bus (so that
neutral was separate from ground), but the ground bus is bonded to the
panel (and is tied to the main panel ground via a bare conductor).

The inspector signed off on it no problem.

What's the point of an insulated ground?

Chris

Lew Hodgett wrote:
> Chris Friesen wrote:
> > What's the point of an insulated ground?
>
> It allows the entire distribution system to be grounded at the service
> entrance point.
>
> Single point grounding eliminates "Ground Loops" which can be quite nasty.

I'm aware of ground loops. What does this have to do with an insulated
ground bus in a subpanel?

In my panel for instance, the ground bus is bonded to the panel, which
is in turn grounded via a conductor going back to the main panel. As
you mentioned, the entire system is grounded at the service entrance.

Chris

Chris Friesen wrote:

> What's the point of an insulated ground?

It allows the entire distribution system to be grounded at the service
entrance point.

Single point grounding eliminates "Ground Loops" which can be quite nasty.

The cathodic electrode industry exists to minimize the effects of
"Ground loops" or stray electrical currents in the soil.

Lew

On Mon, 16 Jul 2007 21:15:48 -0700, Steve <[email protected]>
wrote:

>Bob AZ wrote:
>
>>
>> 2? ton split unit. Smallest split unit I could locate. Forgot the
>> brand. Only 13 SEER. Shop for the most SEER. I really pays off and the
>> higher SEER units are usually better built. I have a a friend now who
>> will find me what I want were I need to do it again.
>
>All the units I've found on-line are 13 SEER. I found one at 14 SEER
>that's about $300 more than the others.
>

Keep looking. Go to 15 SEER, and take a $300 tax credit to offset the
cost. make up the rest over a couple of years with energy savings. I
think a shop AC qualifies if it is at the same address as your home,
but you may need to check that.

http://www.energystar.gov/index.cfm?c=products.pr_tax_credits#s2

Frank


>>
>> I installed it myself and had the refrigerant lines soldered/done by a
>> AC technician. He does them everyday.Shop for what you want. It is out
>> there. I also made sure I got a 220 unit.
>
>One on-line vendor claims it's illegal for someone who is not
>EPA-certified to mess with refrigerants - is that true?
>
>>
>> Bob AZ
>>

My 2 cents FWIW:

> 1. Do each of these need its own dedicated circuit?

Asside from your noted exceptions (DC&AC), no they do not. My lathe, jointer
and BS share. The BS is 2HP and the Jointer is 1.5 and I can still run them
at the same time on a 20 amp breaker. I have not had them both "under load"
simultaniously through.

How big 20 or 30
> amp?

I wired all my 220 with 10ga, just in case I ever install a 5HP something.

Do all 220 machines operate at the same amperage or use the same
> plug?

Most machines don't even come with a plug, you get to put on anything you
like. So long as it is rated for more than your machine, you're OK. Some
folks insist on twist-lock... I happen to think it's overkill except when
it's there is a specific pull-out hazzard

> 2. With some of these machines situated in the middle of the floor how
> would you get power to them? Extension cord, ceiling drop?

I put it in (below) the floor, but that does seriously limit your options
later on. I'm glad I did, but in my 20x25 shop, there was exactly one place
I was going to put the stationary TS. With 30x30, I wuld imagine that you
put a higher premium on flexibility.

> 3. If an extension cord is used, would placing the 220 outlets at
> floor level be appropriate? And placing the 110 outlets at >48"? Is
> there a need for placing 220 higher than ground level?

I think that makes sense.... all this discussion about the ergonomic hight
of an outlet seems to skim over the fact that there alot of devices that
seldom get unplugged (prill press), and then there are things like a palm
sander which is in and out all the time. I guess it depends on how you
work. I have all of my recepticals low and it does not create any problem
for me. That's because I have power strips just below counter height at each
of my workstations. Smaller portable tools et plogged into the ergonomically
placed strips, and the stationary tools and the power strips plug in down
low where the cords are out of the way.

>
> 4. What size of extension cord, 12/3 or 10/3?

For a 220 machine, that depends on the amperage draw. Since you will likely
have to assemble/attach cords for these machines, so just make exactly what
you need/want in length and pass on the extension cord. I was able to get
some really nice 12 gauge cord stock from the local electrical supply that
was really nice: thick, plyable rubbery insulation for a very reasonable
price.

> 5. Type of wiring. 12/3 or 10/3? Would you wire the 110 with the same?
> Why?

220 - 10/3...just in case you need it some day. 110V... no reason to go
beyond 12/3 as there's not much out there that will draw more than 15 Amps
(continuously) that runs on 110V.

-Steve



--
Posted via a free Usenet account from http://www.teranews.com

In article <0s9ni.4506$4J4.3563@trndny05>, Nova <[email protected]> wrote:
>Chris Friesen wrote:
>> Lew Hodgett wrote:
>>
>>> Chris Friesen wrote:
>>> > What's the point of an insulated ground?
>>>
>>> It allows the entire distribution system to be grounded at the service
>>> entrance point.
>>>
>>> Single point grounding eliminates "Ground Loops" which can be quite
>>> nasty.
>>
>> I'm aware of ground loops. What does this have to do with an insulated
>> ground bus in a subpanel?
>>
>> In my panel for instance, the ground bus is bonded to the panel, which
>> is in turn grounded via a conductor going back to the main panel. As
>> you mentioned, the entire system is grounded at the service entrance.
>>
>The resulting ground loop (parallel neutral current paths) will allow
>dangerous objectionable current to flow onto metal parts of the
>electrical installation (and onto metal piping and structural steel).

*What* "resulting ground loop"?

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

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

On Mon, 16 Jul 2007 23:12:43 GMT, Lew Hodgett
<[email protected]> wrote:

>Somebody wrote:
>

>
>Add a 2p-60A main c'bkr kit along with an insulated ground bus bar
>since this is a sub panel.

Easily obtained? None of the low cost "packaged panels" I've seen
have a 60 main. 60 main will be a different configuration than the 60
branch? Electrical supply house?

Insulated ground bar means remove the strap to the nuetral if so
configured? But ground buss needs to remain bonded to the panel,
correct?

Thanks,

Frank

>

>

<<<<<<<<<< SNIPPAGE >>>>>>>>>
> For a one-man shop, 60A should be plenty. Why 200A?
>> A number of the machines, TS, BS, Jointer, DC, etc. will be 220.
>>

60A??? I could use almost that much just for lighting. :-)

Wayne

In article <[email protected]>, Mike Berger <[email protected]> wrote:
>It's very common with metalworking machines. Coolant pumps and
>DRO's operate on 117 v while the big motor operates on 220.

Well, of course we were talking about woodworking machinery here... :-)

>It seems silly to me to go to the trouble of wiring new circuits
>without installing the third wire. It's a lot more trouble to add
>later.

Which is why I said this, in the part that you snipped:

If you want to plan for "in case you need it some day" it's better to not
run cables at all, but instead pull individual conductors through conduit:
pull what you need now, now; pull what you need later, later.


>
>Doug Miller wrote:
>> In article <[email protected]>, "Stephen M"
> <[email protected]> wrote:
>>
>>> 220 - 10/3...just in case you need it some day.
>>
>> We've had that discussion here before. :-)
>>
>> There's *no* reason to use 3-conductor cable for 240V power tools. It's just
>> unnecessary expense. Three-conductor cable is needed for combined 240/120
>> loads such as a range or a dryer, that have 240V heating elements and 120V
>> motors and/or control circuits. A power tool with a 240V motor needs only
>> two-conductor cable; there isn't even anything to attach the third conductor
>> to, if it's present.
>>

--
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]>, NoOne N Particular <[email protected]> wrote:
><<<<<<<<<< SNIPPAGE >>>>>>>>>
>> For a one-man shop, 60A should be plenty. Why 200A?
>>> A number of the machines, TS, BS, Jointer, DC, etc. will be 220.
>>>
>
>60A??? I could use almost that much just for lighting. :-)

60A @ 240V = 14.4KW = 3,600 standard 48" fluorescent tubes.

Atsa lotsa lights!

--
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]>, Lew Hodgett <[email protected]> wrote:
>Frank Boettcher wrote:
>
> >But ground buss needs to remain bonded to the panel,
> > correct?
>
>NO, not at the sub panel, but yes at the main service entrance panel.

Yes, at the subpanel, as well as at the main panel. He's asking about the
ground bus. Not the neutral bus.

Correct is:
Ground bus *must* be bonded to panel chassis in main *and* subpanels.
Neutral bus *must* be bonded to ground in main panel.
Neutral bus *must*not* be bonded to ground in a subpanel.

--
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]>, "Stephen M" <[email protected]> wrote:

>220 - 10/3...just in case you need it some day.

We've had that discussion here before. :-)

There's *no* reason to use 3-conductor cable for 240V power tools. It's just
unnecessary expense. Three-conductor cable is needed for combined 240/120
loads such as a range or a dryer, that have 240V heating elements and 120V
motors and/or control circuits. A power tool with a 240V motor needs only
two-conductor cable; there isn't even anything to attach the third conductor
to, if it's present.

If you want to plan for "in case you need it some day" it's better to not
run cables at all, but instead pull individual conductors through conduit:
pull what you need now, now; pull what you need later, later.

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

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

Somebody wrote:

> The NEC allows a 60 amp feed from the house or another sub panel, to
> feed directly to the additional subpanel buss without using a main
> breaker in the additional subpanel. The 125 amp panel comes without a
> main breaker.


Be careful, the "six hand rule" applies.

IOW, all power must be disconnected with a maximum of six motions of
the hand.

Install a 2P-60 as a branch c'bkr in the main panel.

Upgrade the PVC conduit size at least one size, maybe two.

Conduit is cheap, straining your back isn't.

Install a 125 MLO, 12/24 surface mount panel in shop(12-1" or 24, 1/2"
branch spaces).

Add a 2p-60A main c'bkr kit along with an insulated ground bus bar
since this is a sub panel.

Use 1P-20 c'bkrs for all 120V circuits of which at least 4 are
dedicated to lighting.

240V circuits:

Dedicate a 2P-50 for a 5HP air compressor

2P-30 for the balance.

Run every thing you can at 240V, especially stationary tools like DC,
TS, Jointer, dedicating an individual c'bkr for each load.

Use 30A locking receptacles & plugs for 240V services.

You do the above, the inspector will smile and give you your permit.

Lost count of how many of the above packages I sold over the years,
but it was a bunch.


Lew

PS: Wire all your receptacles in 4" (2 gang) boxes.

Makes life a LOT easier.

In article <[email protected]>, Frank Boettcher <[email protected]> wrote:
>On Mon, 16 Jul 2007 23:12:43 GMT, Lew Hodgett
><[email protected]> wrote:

>>Add a 2p-60A main c'bkr kit along with an insulated ground bus bar
>>since this is a sub panel.

>Insulated ground bar means remove the strap to the nuetral if so
>configured? But ground buss needs to remain bonded to the panel,
>correct?

He's confused. The subpanel needs an insulated *neutral* bus. The ground bus
*must* be bonded to the panel chassis. And the bonding strap between the
neutral and ground buses must be 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]>, ed louie says...
>
> 1. Do each of these need its own dedicated circuit? How big 20 or 30
> amp? Do all 220 machines operate at the same amperage or use the same
> plug? I have heard mention of the different plugs but don't know the
> difference.
>
> 2. With some of these machines situated in the middle of the floor how
> would you get power to them? Extension cord, ceiling drop?
>
> 3. If an extension cord is used, would placing the 220 outlets at
> floor level be appropriate? And placing the 110 outlets at >48"? Is
> there a need for placing 220 higher than ground level?
>

I'll share my thoughts on the things I know about (no idea about your localised
extention gauges or plug styles).

You're unlikely to get single phase machines that draw substantially more than
10A. Most will draw less. My shop is wired 20A 240V on two circuits. Circuit
breakers are thermal as well as overload type, and I've not had a problem with
them tripping, ever. On very rare occasions I have 2 big machines running and 1
small (RAS, planer, compressor/extractor)- usually only 1big, 1 small.
Only time those breakers tripped was when I tried to continuously run a single
phase welder on a hot day. (the welding took place outside the shop, on the
drive, b.t.w!)

I have 1 ceiling drop, for handheld tools at the assembly table and use
extention cord for my over-and-under which gets moved around. Both have their
disadvantages.

Personally I wouldn't put the outlets in a workshop too low. Think back-pain.
Think sawdust. Think spillages. I'll have mine so I don't need to bend over to
get at them, thanks. Speeds things up, too.

-P.

--
=========================================
firstname dot lastname at gmail fullstop com

In article <[email protected]>, dpb <[email protected]> wrote:
>Doug Miller wrote:
>> In article <[email protected]>, "Stephen M"
> <[email protected]> wrote:
>>
>>> 220 - 10/3...just in case you need it some day.
>>
>> We've had that discussion here before. :-)
>>
>> There's *no* reason to use 3-conductor cable for 240V power tools. It's just
>> unnecessary expense. Three-conductor cable is needed for combined 240/120
>> loads such as a range or a dryer, that have 240V heating elements and 120V
>> motors and/or control circuits. A power tool with a 240V motor needs only
>> two-conductor cable; there isn't even anything to attach the third conductor
>> to, if it's present.
>
>I have seen (but _very_ few (well, actually, precisely two :) ) --don't
>know of any current-day that do) a couple of planers that used that as
>well -- the main feed/cutterhead motor was 220V while the table lift and
>an auxiliary sharpening attachment were 110V. Fella' in a shop in VA
>had them. But certainly I'm unaware of anything currently on the market
>set up that way.

Well, yes, as always, the requirements of any specific tool or appliance trump
"general rules". Interesting, though -- I didn't know anything of the sort had
ever been produced. Wonder if some of that might have been aftermarket mods?
>
>> If you want to plan for "in case you need it some day" it's better to not
>> run cables at all, but instead pull individual conductors through conduit:
>> pull what you need now, now; pull what you need later, later.
>
>That's not bad advice, either... :)
>

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

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

Frank Boettcher wrote:

> Again, goes against everything I've read and instinctively know to be
> true. Without the bond, the subpanel panel itself is not grounded and
> it has to be.

Mea Culpa, Mea Culpa, Thank you for being my editor.

That's what happens when you engage fingers before brain.

My previous post is in error as noted by Frank.

The sub panel gets a ground bar with the panel tub (enclosure) bonded
to it with the bonding strap and an insulated neutral bus that then
gets carried back to the service entrance panel.


Sorry for the confusion.

Lew

In article <[email protected]>, Chris Friesen <[email protected]> wrote:
>Lew Hodgett wrote:
>> Chris Friesen wrote:
>> > What's the point of an insulated ground?
>>
>> It allows the entire distribution system to be grounded at the service
>> entrance point.
>>
>> Single point grounding eliminates "Ground Loops" which can be quite nasty.
>
>I'm aware of ground loops. What does this have to do with an insulated
>ground bus in a subpanel?

Absolutely nothing. He may be confusing "insulated ground" with "isolated
ground" or perhaps with "insulated neutral."

In any event, it is a Code violation to insulate the grounding bus from the
panel chassis in either a main panel or a subpanel: metal enclosures are
*required* to be grounded.
>
>In my panel for instance, the ground bus is bonded to the panel, which
>is in turn grounded via a conductor going back to the main panel. As
>you mentioned, the entire system is grounded at the service entrance.

And that is as it should be. This talk of insulating the grounding bus from
the panel is nonsense.

--
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]>, Lew Hodgett <[email protected]> wrote:
>Mike Berger wrote:
>
> > It's very common with metalworking machines.
><snip>
>
>You must be new.
>
>Trying to talk to Miller is like pissing up wind.
>
>After a while, you know better.

Pissed off because I pointed out your electrical errors *again*, I see...

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

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

Chris Friesen wrote:

> I'm aware of ground loops. What does this have to do with an
insulated
> ground bus in a subpanel?

Absolutely nothing.

(See my Mea Culpa on my response to Frank.)

It should have read "Insulated neutral bus".

The ground bus with the sub panel bonded to it's ground bus and then
carried back to service entrance will give single point grounding.

Lew

In article <[email protected]>, dpb <[email protected]> wrote:
>Doug Miller wrote:
>> In article <[email protected]>, NoOne N
> Particular <[email protected]> wrote:
>>> <<<<<<<<<< SNIPPAGE >>>>>>>>>
>>>> For a one-man shop, 60A should be plenty. Why 200A?
>>>>> A number of the machines, TS, BS, Jointer, DC, etc. will be 220.
>>>>>
>>> 60A??? I could use almost that much just for lighting. :-)
>>
>> 60A @ 240V = 14.4KW = 3,600 standard 48" fluorescent tubes.
>>
>> Atsa lotsa lights!
>
>Not many shadows, one would presume?
>
>Eliminates need for space heating in the winter, too, as a bonus!

Yah, but what about the A/C bills in the summer? :-b

--
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]>, Frank Boettcher <[email protected]> wrote:
>On Tue, 17 Jul 2007 16:14:22 GMT, Lew Hodgett
><[email protected]> wrote:
>
>>NO, what you are describing is a bonding strap used to bond the
>>neutral to the enclosure when the panel is used as a service entrance
>>panel.
>>
>No, I'm describing a tie bar that ties the nuetral and ground buses
>together which is normal in a service entrance panel but not for a
>subpanel.

Gentlemen, you're *both* right here. In main panels, as you're both aware, the
neutral bus is bonded to ground. The method of doing so varies depending on
manufacturer. I've seen four different types of jumpers:
- bonding strap connecting the neutral bus to the panel chassis
- bonding strap connecting the neutral and ground buses
- bonding *screw* through the neutral bus into the panel chassis
- solid copper wire connecting the two buses
Regardless of the method, the jumper must be removed if the panel is used as a
subpanel.

>>An insulated ground bus is exactly that.
>>
>>It will look like the neutral bus but be insulated from the panel.

You've got that backwards -- it's the *neutral* bus that's insulated from the
panel, *not* the ground bus.

Ground bars *must* be bonded to the panel.
>>
>Goes against everything I've read. In many main panels the nuetral
>and ground buss are tied together with a strap or tie bar, which
>insures that both buses are grounded. Removing that strap in a panel
>makes it suitable to use as a subpanel. Both the insulated ground and
>the nuetral in the sub continue to be grounded through their paths
>back to the main.

Exactly right.

>> >But ground buss needs to remain bonded to the panel,
>> > correct?
>>
>>NO, not at the sub panel, but yes at the main service entrance panel.

Wrong. Ground bus *must* be bonded to the panel, without regard to whether
it's a main or sub.
>
>Again, goes against everything I've read and instinctively know to be
>true. Without the bond, the subpanel panel itself is not grounded and
>it has to be.

Exactly right.

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

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

ed louie wrote:
...
> The shop will be 30x30 with 10' ceilings, concrete floor. Power will
> be from a 200 amp sub panel. One man workshop with no more than one
> machine with exceptions, air compressor, DC, operating at a time.
>
> A number of the machines, TS, BS, Jointer, DC, etc. will be 220.
>
> 1. Do each of these need its own dedicated circuit? How big 20 or 30
> amp? Do all 220 machines operate at the same amperage or use the same
> plug? I have heard mention of the different plugs but don't know the
> difference.

If you're not using more than one at a time, then more than a couple
circuits would be an absolute requirement. That said, I'd tend to over
design rather than under -- it's relatively cheap extra material in the
scheme of things and almost no extra labor at the same time.

Of course not...a 1hp motor doesn't draw what a 2hp motor does and
certainly not everything has the same size motor.

If it's new, I'd go w/ 30A just on general principles of why limit
yourself from the git-go...

Plugs are rated for current/voltage as well and prong styles are made to
prevent plugging the wrong one in the wrong place.

Pick a standard outlet form factor that has the rating of the largest
needed and match the cords to the outlets. The convenience of a
consistent form factor in the long run far outweighs an initial
conversion process imo.

> 2. With some of these machines situated in the middle of the floor how
> would you get power to them? Extension cord, ceiling drop?

If at all possible, install a raised flooring system and run power and
DC there. If not feasible, overhead drops. I'm assuming from the tone
this is all relatively small stuff, not the 7.5hp planer a concurrent
thread is discussing...

As for extension cords for stationary machines, no!, No!, and NO!

> 3. If an extension cord is used, would placing the 220 outlets at
> floor level be appropriate? And placing the 110 outlets at >48"? Is
> there a need for placing 220 higher than ground level?

Extension cords are for temporary use _only_ and shouldn't be necessary
at all if you wire the shop adequately.

I run all handybox outlets at >48" in shop for convenience in reaching
them when standing and so can occasionally do things like lean a 4x8
sheet of sheet goods against the wall w/o obstructing them. That's my
personal preference and practice, if you have other reasons more
overriding, go for it however you want.

In the bench areas, I make sure there are quad outlets at least every
six feet. I place 220V on the basis of equipment and keep expansion in
mind.

> 4. What size of extension cord, 12/3 or 10/3?

None...except for hand tools, and they can be 12.

> 5. Type of wiring. 12/3 or 10/3? Would you wire the 110 with the same?
> Why?

Depends on the service...I'd go 30A for the 220 for sure, but I have
stuff of the size that requires it. If you're smaller hobbyest type and
don't have and don't foresee getting bigger, might get away w/ 20A
service, but again, why scrimp?

20A for 110 hand tools, etc., is far less problematical, of course
unless you have some sizable single-voltage motors that need more. I'd
avoid them, but if you already have them and they aren't dual voltage
you wouldn't want to be limited from the start...

If you haven't, do a google groups archive search -- there was a really
good discussion of just this subject within the year for sure...

--

Peter Huebner wrote:
...
> You're unlikely to get single phase machines that draw substantially more than
> 10A.

http://www.powermatic.com/shop/index.cfm?navPage=4&iid=12737&tab=Details

All you need is $$$! :) I personally would be lost w/o mine...

Somehow I suspect OP doesn't, though... :) Even then, I'd still
definitely recommend going w/ 30A on a new shop -- just seems cutting
corners where incremental cost just isn't that much.

Again, of course, imo, ymmv, $0.02, etc., etc., ...

--

Doug Miller wrote:
> In article <[email protected]>, NoOne N Particular <[email protected]> wrote:
>> <<<<<<<<<< SNIPPAGE >>>>>>>>>
>>> For a one-man shop, 60A should be plenty. Why 200A?
>>>> A number of the machines, TS, BS, Jointer, DC, etc. will be 220.
>>>>
>> 60A??? I could use almost that much just for lighting. :-)
>
> 60A @ 240V = 14.4KW = 3,600 standard 48" fluorescent tubes.
>
> Atsa lotsa lights!

Not many shadows, one would presume?

Eliminates need for space heating in the winter, too, as a bonus!

:)
--

Doug Miller wrote:
> In article <[email protected]>, "Stephen M" <[email protected]> wrote:
>
>> 220 - 10/3...just in case you need it some day.
>
> We've had that discussion here before. :-)
>
> There's *no* reason to use 3-conductor cable for 240V power tools. It's just
> unnecessary expense. Three-conductor cable is needed for combined 240/120
> loads such as a range or a dryer, that have 240V heating elements and 120V
> motors and/or control circuits. A power tool with a 240V motor needs only
> two-conductor cable; there isn't even anything to attach the third conductor
> to, if it's present.

I have seen (but _very_ few (well, actually, precisely two :) ) --don't
know of any current-day that do) a couple of planers that used that as
well -- the main feed/cutterhead motor was 220V while the table lift and
an auxiliary sharpening attachment were 110V. Fella' in a shop in VA
had them. But certainly I'm unaware of anything currently on the market
set up that way.

> If you want to plan for "in case you need it some day" it's better to not
> run cables at all, but instead pull individual conductors through conduit:
> pull what you need now, now; pull what you need later, later.

That's not bad advice, either... :)

--

Doug Miller wrote:
> In article <[email protected]>, dpb <[email protected]> wrote:
>> Doug Miller wrote:
>>> In article <[email protected]>, "Stephen M"
>> <[email protected]> wrote:
>>>> 220 - 10/3...just in case you need it some day.
>>> We've had that discussion here before. :-)
>>>
>>> There's *no* reason to use 3-conductor cable for 240V power tools. It's just
>>> unnecessary expense. Three-conductor cable is needed for combined 240/120
>>> loads such as a range or a dryer, that have 240V heating elements and 120V
>>> motors and/or control circuits. A power tool with a 240V motor needs only
>>> two-conductor cable; there isn't even anything to attach the third conductor
>>> to, if it's present.
>> I have seen (but _very_ few (well, actually, precisely two :) ) --don't
>> know of any current-day that do) a couple of planers that used that as
>> well -- the main feed/cutterhead motor was 220V while the table lift and
>> an auxiliary sharpening attachment were 110V. Fella' in a shop in VA
>> had them. But certainly I'm unaware of anything currently on the market
>> set up that way.
...

I believe these were factory jobs -- I've wished more than once I had
"bought'en" :) one of them from Eddie when he was selling them as he was
enlarging his shop, but $500 was a _lot_ of money back then and I was
just out of school so the $150 for the small shaper and 6" Rockwell
jointer was all I could manage at the time.

As I recall, everything looked to match and the controls were all
integral to the machine so I don't think it was an add-on. But I was
young and pretty new to stuff at the time so didn't stick w/ me what
they really were. Somebody long gone from the business now, I'm sure.
They were a nondescript gray, darker than Rockwell so no real clue to
try to match up like a recognizable PM green or some such.

He said he had bought'en them from a factory auction somewhere in PA --
they had had a production line of 25 of them -- 5 rows of 5 in line.
Started at one end w/ rough stock, came out at the other with their
surfaced/thicknessed stock for the sawyers on the other. They had
replaced the 25 machines/50 employees with 2 large planers and a wide
belt sander and five guys. About 1969/1970 when I met Eddie by
answering his classified ad. He had had the machines 2-3 years at that
point. I'd guess they were at least 20 years old if a day, probably
closer to 30 then...

--

It's very common with metalworking machines. Coolant pumps and
DRO's operate on 117 v while the big motor operates on 220.
It seems silly to me to go to the trouble of wiring new circuits
without installing the third wire. It's a lot more trouble to add
later.

Doug Miller wrote:
> In article <[email protected]>, "Stephen M" <[email protected]> wrote:
>
>> 220 - 10/3...just in case you need it some day.
>
> We've had that discussion here before. :-)
>
> There's *no* reason to use 3-conductor cable for 240V power tools. It's just
> unnecessary expense. Three-conductor cable is needed for combined 240/120
> loads such as a range or a dryer, that have 240V heating elements and 120V
> motors and/or control circuits. A power tool with a 240V motor needs only
> two-conductor cable; there isn't even anything to attach the third conductor
> to, if it's present.
>

Hi Ed,

New shop? Good for you! Are you planning to stay there long?

If so I'd put a minimum four 120V 15A and two 240V 20A receptacles every 15
feet all around the inside walls, each drop on its own circuit. Install air
and dust collector drops at the same time. Put some power, air and DC
receptacles in the ceiling. Put lights on their own circuit. Install
retractable power and air cord reels. Install a dedicated circuit for your
DC and air compressor.

Plan where you are going to put your table saw and work table. If in the
middle of the room then install a couple of 4" conduits into the floor.

Personally I prefer shop receptacles at 48" off the ground.

Spend money and insulate the shop well. Put in a good heating/cooling/air
make up system.

For a good shop I recommend to spend a little more now or end up paying a
lot more later.

Mike

<ed louie> wrote in message
news:[email protected]...
>I am in the process of designing and building a new 30'x30' shop. A
> few questions concerning wiring have come up that I would like some
> input. I have read a lot of the posts about wiring but still confused
> on a few things.
>
> The shop will be 30x30 with 10' ceilings, concrete floor. Power will
> be from a 200 amp sub panel. One man workshop with no more than one
> machine with exceptions, air compressor, DC, operating at a time.
>
> A number of the machines, TS, BS, Jointer, DC, etc. will be 220.
>
> 1. Do each of these need its own dedicated circuit? How big 20 or 30
> amp? Do all 220 machines operate at the same amperage or use the same
> plug? I have heard mention of the different plugs but don't know the
> difference.
>
> 2. With some of these machines situated in the middle of the floor how
> would you get power to them? Extension cord, ceiling drop?
>
> 3. If an extension cord is used, would placing the 220 outlets at
> floor level be appropriate? And placing the 110 outlets at >48"? Is
> there a need for placing 220 higher than ground level?
>
> 4. What size of extension cord, 12/3 or 10/3?
>
> 5. Type of wiring. 12/3 or 10/3? Would you wire the 110 with the same?
> Why?
>
> I am sure there will be more questions once these get answered, thanks
> for your input.
>
> Ed

On Mon, 16 Jul 2007 08:10:08 -0700, Bob AZ <[email protected]>
wrote:

>On Jul 16, 4:58?am, Frank Boettcher <[email protected]> wrote:
>> On Sun, 15 Jul 2007 20:55:17 -0700, Bob AZ <[email protected]>
>> wrote:
>>
>>
>>
>> >> I'm planning something similar.
>>
>> So you put a 60 amp breaker in the main (house) panel and ran a
>> circuit to the subpanel. Did you pull the 125 main breaker from your
>> subpanel and put a 60 amp main in the sub?
>>
>> what feed did you use. #4/3 wg Type SER or individual # 6 THWN wires
>> in conduit with a # 10 ground? Or did you go oversize from the
>> minimum required to carry 60 amps. Did you cost the difference
>> between SER and conduit. Did you have to go underground or all above?
>>
>> Why the extra ground rod? Does the code require it? The sub ground
>> bus is tied back to the main panel ground bus with the subpanel bonded
>> to the ground bus but not strapped to the nuetral bus, I assume.
>>
>> FRank
>
>Frank
>
>The NEC allows a 60 amp feed from the house or another sub panel, to
>feed directly to the additional subpanel buss without using a main
>breaker in the additional subpanel. The 125 amp panel comes without a
>main breaker. Home Depot.
>I used #6 THHN wire. 2 hot legs, 1 neutral and a ground from the house
>panel. #6 is oversize but I always go oversize on the feed to any
>panel. This was an underground run, 85'.
>
>The extra ground rod is not required by code. I did it for lightning
>protection. I would lose lots of things without it since we have nasty
>lightning every summer. The #6 ground back to the main panel is
>required and would be wiped out ion a lightning strike every summer.
>Thus the ground rod. There is no wire size that will take a lightning
>strike of any intensity.
>
>Where I live we have soil conditions such that one goes PVC conduit or
>else. Even EMT conduit eventually disappears due to electrolysis. I
>know it sounds funny but just this last week a friend had to start
>replacing a service to his shop that was in EMT conduit. And direct
>burial is nice but requires a 12" sand barrier. Thus PVC conduit is
>the less exensive way to go. Costs a bit less and lasts forever. I
>don't use Al wire at all. Too many longterm problems. The power
>company has my house fed, underground, with AL and they will
>eventually have to replace it. The neutral usually burns in two.
>I knew PVC underground was cheaper and while the man was preparing my
>site for the slab he just took another hour to dig the electric
>trench. I had the conduit ready to drop in and he covered it up in
>about 2 minutes with clean fill. We have lots of rocks that move
>around a lot.
>Under certain conditions the NEC requires a ground the size of the
>current carrying conductors or larger. With what I know now I would go
>even larger. It was not much more money. I probably spent less than
>$100.00 for all the electric add ons. It is cheap insurance. And I had
>less to worry about for all the other things like cable TV, intercom,
>computer etc.
>
>Take care
>Bob AZ
>
Thanks, useful information. My shop, although a completely separate
building, is attached to the house, in theory, as a breezeway offers a
protected run without having to make the choice between direct burial
or conduit type. Think I will put a main breaker in my subpanel
though.


Better check that NEC. My understanding is if it is a completely
separate building and has over six spaces it's required. But I never
checked it, going by an article I read in Fine Hombuilding (April
2003)

Frank

Chris Friesen wrote:

> Now I'm no pro, but it seems like some of these suggestions are
overkill.

One word: Standardization.

You buy wire in full spools instead of cut lengths.

You buy devices in quantity.

You provide for future expansion.

Overall, you save money.

Lew

Lights on dedicated circuit is a great idea. It stinks having the
lights go off because something poped the circuit.

I did 20 amp circuits in my house using 12 guage wire. The air
compressor and the vacuum cleaner in the garage on the same breaker
sometimes pops when bead blasting.

Circuit size of 220 is dictated by equipment. Your big air compressor
might spec a bigger circuit than the table saw.

On Sun, 15 Jul 2007 20:50:14 -0500, "Epictitus"
<[email protected]> wrote:

>Hi Ed,
>
>New shop? Good for you! Are you planning to stay there long?
>
>If so I'd put a minimum four 120V 15A and two 240V 20A receptacles every 15
>feet all around the inside walls, each drop on its own circuit. Install air
>and dust collector drops at the same time. Put some power, air and DC
>receptacles in the ceiling. Put lights on their own circuit. Install
>retractable power and air cord reels. Install a dedicated circuit for your
>DC and air compressor.
>
>Plan where you are going to put your table saw and work table. If in the
>middle of the room then install a couple of 4" conduits into the floor.
>
>Personally I prefer shop receptacles at 48" off the ground.
>
>Spend money and insulate the shop well. Put in a good heating/cooling/air
>make up system.
>
>For a good shop I recommend to spend a little more now or end up paying a
>lot more later.
>
>Mike
>
><ed louie> wrote in message
>news:[email protected]...
>>I am in the process of designing and building a new 30'x30' shop. A
>> few questions concerning wiring have come up that I would like some
>> input. I have read a lot of the posts about wiring but still confused
>> on a few things.
>>
>> The shop will be 30x30 with 10' ceilings, concrete floor. Power will
>> be from a 200 amp sub panel. One man workshop with no more than one
>> machine with exceptions, air compressor, DC, operating at a time.
>>
>> A number of the machines, TS, BS, Jointer, DC, etc. will be 220.
>>
>> 1. Do each of these need its own dedicated circuit? How big 20 or 30
>> amp? Do all 220 machines operate at the same amperage or use the same
>> plug? I have heard mention of the different plugs but don't know the
>> difference.
>>
>> 2. With some of these machines situated in the middle of the floor how
>> would you get power to them? Extension cord, ceiling drop?
>>
>> 3. If an extension cord is used, would placing the 220 outlets at
>> floor level be appropriate? And placing the 110 outlets at >48"? Is
>> there a need for placing 220 higher than ground level?
>>
>> 4. What size of extension cord, 12/3 or 10/3?
>>
>> 5. Type of wiring. 12/3 or 10/3? Would you wire the 110 with the same?
>> Why?
>>
>> I am sure there will be more questions once these get answered, thanks
>> for your input.
>>
>> Ed
>

On Tue, 17 Jul 2007 16:14:22 GMT, Lew Hodgett
<[email protected]> wrote:

>Frank Boettcher wrote:
>
> > Easily obtained? None of the low cost "packaged panels" I've seen
> > have a 60 main. 60 main will be a different configuration than the 60
> > branch? Electrical supply house?
>
>The 60A bkr is the same, but has different hardware to be used as a
>main bkr.
>
>Any decent electrical distributer can help you.
>
> > Insulated ground bar means remove the strap to the nuetral if so
> > configured?
>
>NO, what you are describing is a bonding strap used to bond the
>neutral to the enclosure when the panel is used as a service entrance
>panel.
>
No, I'm describing a tie bar that ties the nuetral and ground buses
together which is normal in a service entrance panel but not for a
subpanel.

>An insulated ground bus is exactly that.
>
>It will look like the neutral bus but be insulated from the panel.
>

Goes against everything I've read. In many main panels the nuetral
and ground buss are tied together with a strap or tie bar, which
insures that both buses are grounded. Removing that strap in a panel
makes it suitable to use as a subpanel. Both the insulated ground and
the nuetral in the sub continue to be grounded through their paths
back to the main.


>


> >But ground buss needs to remain bonded to the panel,
> > correct?
>
>NO, not at the sub panel, but yes at the main service entrance panel.
>

Again, goes against everything I've read and instinctively know to be
true. Without the bond, the subpanel panel itself is not grounded and
it has to be.

Frank

Steve wrote:


> One on-line vendor claims it's illegal for someone who is not
> EPA-certified to mess with refrigerants - is that true?

These days, yes.

Has to do with protecting the ozone layer.

Checked the price of 12 or 22, if you can even find it.

Lew

In article <[email protected]>, ed louie wrote:
>I am in the process of designing and building a new 30'x30' shop. A
>few questions concerning wiring have come up that I would like some
>input. I have read a lot of the posts about wiring but still confused
>on a few things.
>
>The shop will be 30x30 with 10' ceilings, concrete floor. Power will
>be from a 200 amp sub panel. One man workshop with no more than one
>machine with exceptions, air compressor, DC, operating at a time.

For a one-man shop, 60A should be plenty. Why 200A?
>
>A number of the machines, TS, BS, Jointer, DC, etc. will be 220.
>
>1. Do each of these need its own dedicated circuit?

Depends on the tool, but generally, no -- especially since in a one-man shop,
you'll not be simultaneously using any *two* major tools. One exception is the
dust collector: presumably, it will be on nearly all the time. I'd put that on
a dedicated circuit. But all the other tools you named could easily share the
same circuit, since only one of them will be on at a time.

The other exception is the air compressor, which also could be powered on at
the same time as other tools. If you need an air compressor big enough to need
240V, put it on a dedicated circuit too.

>How big 20 or 30 amp?

Again, depends on the tool. You may not need even 20A for the dust collector
or bandsaw. If you run 10AWG wire for all your 240V circuits, you can use 15,
20, or 30A receptacles and breakers as needed.

> Do all 220 machines operate at the same amperage or use the same
>plug?

No.

>I have heard mention of the different plugs but don't know the difference.

15, 20, and 30A receptacles all have different configurations, in order to
prevent plugging a 30A tool into, say, a 20A circuit. Size the circuit, and
the receptacles on it, to the tools you will install.
>
>2. With some of these machines situated in the middle of the floor how
>would you get power to them? Extension cord, ceiling drop?

Largely a matter of personal preference. I don't have a whole lot to say on
this one, because I've never had a shop big enough for that to be an issue. I
do have a 120V retractable extension cord mounted to the ceiling near the
center of my shop, and that's *damned* convenient -- so based on that
admittedly limited experience, ceiling drop would be my preference. Might not
be yours, though.

I'm sure you'll see plenty of comments on this from others, giving the pros
and cons of different methods. Consider the comments, and make your choice.
>
>3. If an extension cord is used, would placing the 220 outlets at
>floor level be appropriate?

Not unless you enjoy bending and stooping. :-)

>And placing the 110 outlets at >48"?

Yep. Make sure you have the *bottom* of the receptacle box at 48+", not the
center.

>Is there a need for placing 220 higher than ground level?

It's kinder to your back and knees.
>
>4. What size of extension cord, 12/3 or 10/3?

Depends on the tool: 12AWG is the minimum for 20A, 10AWG is the minimum for
30A.
>
>5. Type of wiring. 12/3 or 10/3?

Wire size depends on the breaker: 12AWG for 20A, 10AWG for 30A. As noted
above, though, I'd run 10AWG for all of them, to enable changing a 20A circuit
to 30A without having to pull new wire.

Note, though, that for 240V branch circuit wiring, you use 12/2 or 10/2, not
xx/3. 240V circuits use two hots and a ground, but no neutral. Mark the white
wire black or red to indicate that it's being used as a hot conductor. (A 10/3
extension cord has three conductors in it, black, white, and green; 10/3
nonmetallic cable has *four* conductors, black, red, white, and bare. You only
need three.)

>Would you wire the 110 with the same?

Yep -- that is, using 10/2 or 12/2 as appropriate, not xx/3.

>Why?

Because that's what's needed.

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

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

On Mon, 16 Jul 2007 08:15:39 -0700, Bob AZ <[email protected]>
wrote:
> Only 13 SEER. Shop for the most SEER. I really pays off and the
>higher SEER units are usually better built.

If one gets sold too low of a SEER rating, are they a SEER sucker?

---------------------------------------------
** http://www.bburke.com/woodworking.html **
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On Sun, 15 Jul 2007 20:55:17 -0700, Bob AZ <[email protected]>
wrote:


>

>
>Electric is from main house panel. 60 Amp 220 volts and a 20 amp
>emergency circuit should I trip any breakers on the subpanel in the
>shop. Emergency circuit feeds a 20 amp outlet and a light which comes
>on with loss of either side of the 60 amp 220 circuit.
>
>Subpanel in the shop is a Square D 125 Amp panel that has 8 single
>spaces or 16 ? spaces. Remember the neutral does not get grounded on a
>subpanel. I also have a 10' ground rod for the ground at the shop.
>

>
I'm planning something similar.

So you put a 60 amp breaker in the main (house) panel and ran a
circuit to the subpanel. Did you pull the 125 main breaker from your
subpanel and put a 60 amp main in the sub?

what feed did you use. #4/3 wg Type SER or individual # 6 THWN wires
in conduit with a # 10 ground? Or did you go oversize from the
minimum required to carry 60 amps. Did you cost the difference
between SER and conduit. Did you have to go underground or all above?

Why the extra ground rod? Does the code require it? The sub ground
bus is tied back to the main panel ground bus with the subpanel bonded
to the ground bus but not strapped to the nuetral bus, I assume.

FRank

<ed louie> wrote in message
news:[email protected]...
>I am in the process of designing and building a new 30'x30' shop. A
> few questions concerning wiring have come up that I would like some
> input. I have read a lot of the posts about wiring but still confused
> on a few things.
>
> The shop will be 30x30 with 10' ceilings, concrete floor. Power will
> be from a 200 amp sub panel. One man workshop with no more than one
> machine with exceptions, air compressor, DC, operating at a time.
>
> A number of the machines, TS, BS, Jointer, DC, etc. will be 220.
>
> 1. Do each of these need its own dedicated circuit? How big 20 or 30
> amp? Do all 220 machines operate at the same amperage or use the same
> plug? I have heard mention of the different plugs but don't know the
> difference.
>
Circuits need to handle the largest load.
No, 220 machines do not draw the same amperage.
No, they don't necessarily use the same plugs, but plugs are not that hard
to change.
> 2. With some of these machines situated in the middle of the floor how
> would you get power to them? Extension cord, ceiling drop?
Extension cords are a safety hazard. Ceiling drop can be hard to use.
It just boils down to personal preference.
>
> 3. If an extension cord is used, would placing the 220 outlets at
> floor level be appropriate? And placing the 110 outlets at >48"? Is
> there a need for placing 220 higher than ground level?
I would put them all at the same height. It takes real effort to get a 110
plug
to fit into a 220 socket.
>
> 4. What size of extension cord, 12/3 or 10/3?
Depends on the length of the cord and the amperage draw. There is a table
in the fine manuals.
>
> 5. Type of wiring. 12/3 or 10/3? Would you wire the 110 with the same?
> Why?
Depends on the amperage for the 220 circuits. Just follow the code.
I would wire all 110 circuits with 12/3. This would allow up to 20 amp.
>
> I am sure there will be more questions once these get answered, thanks
> for your input.
>
> Ed

Frank Boettcher wrote:

> Easily obtained? None of the low cost "packaged panels" I've seen
> have a 60 main. 60 main will be a different configuration than the 60
> branch? Electrical supply house?

The 60A bkr is the same, but has different hardware to be used as a
main bkr.

Any decent electrical distributer can help you.

> Insulated ground bar means remove the strap to the nuetral if so
> configured?

NO, what you are describing is a bonding strap used to bond the
neutral to the enclosure when the panel is used as a service entrance
panel.

An insulated ground bus is exactly that.

It will look like the neutral bus but be insulated from the panel.

An electrical distributer will have them as a kit.

>But ground buss needs to remain bonded to the panel,
> correct?

NO, not at the sub panel, but yes at the main service entrance panel.

You need to have a heart to heart with the local building department.

Local codes vary.

Some places will want a ground rod at the sub panel, some may not and
want the earth ground carried all the way back to the service entrance
panel.

If you try to out guess the inspector, you lose, every time out of the
box<G>.

Lew