Tex wrote:
> Take a look at some of the new contactors being used to switch air
> conditioning compressors on/off. Some of the new ones only have ONE
> contact point, yet they switch 240 VAC on/off all the time. Personally,
> I don't like it but it works because current only flows when the two
> legs form a circuit.
Yes, but it still leaves one of the wires at 120V with respect to ground.
With a typical saw setup you could get a nasty shock if you turn off the
machine with a single pole switch, then start working on the motor.
Of course, for safety I'd unplug the machine anyway before working on
it, but still....
Chris
You really don't have a clue, do you?
"Toller" <[email protected]> wrote in message
news:[email protected]...
>
> Well, that's false also. A switch for a motor has to be rated for the hp
of
> the motor. You can be okay on voltage and amperage and still fry the
> switch. It happened on my used table saw; the switch fused closed.
>
>
If you expected to seem credible, you just blew it. Toller normal.
"Toller" <[email protected]> wrote in message
news:[email protected]...
> >
> I would want to test it with volt meter, though an ohm meter ought to be
> okay.
> You sound good to go.
>
>
Toller wrote:
>>>The Switch (A regular switch that is) is ok if you flip it one way and
>>>the motor starts and if you flip it the other way the motor stops.
>>
>>False. The switch is ok if that occurs, *and* the switch is rated for both
>>the
>>voltage and the amperage that it's switching. Better still if the switch
>>disconnects all of the hot conductors going to the motor.
>
>
> Well, that's false also. A switch for a motor has to be rated for the hp of
> the motor. You can be okay on voltage and amperage and still fry the
> switch. It happened on my used table saw; the switch fused closed.
>
>
Humm, something not adding up, Voltage and amperage are the *basic*
elements of electric horsepower. Having the proper Voltage and amperage
rating on a switch would have the proper horsepower rating. Possibly
your used table saw motor may of been defective and drawing a bit more
than it was suppose to. or the V A calculations were wrong. A breaker or
fused should of tripped.
But then again as the tread goes on, someone mentioned something about a
magnetic switch, that is probably the better answer.
Well I was trying to be practical . . . not what if . . ing last time I
checked the average home did not have a 10KV line running to it . . . .
"Chris Friesen" <[email protected]> wrote in message
news:[email protected]...
> Steve DeMars wrote:
> > As to
> > switch safety . . . AMP rating is what you are most concerned with . . .
> > AMPS ! ! !
>
> No, you need to take both into account.
>
> If you take a 10V 100A switch and use it on a 10KV 1A line, you're going
> to have issues.
>
> Chris
Steve W wrote:
> I have a Delta hybrid TS (36-715) and just wired it for 240v. Now the thing
> starts up so fast it makes me worry about belt wear.
>
> Anyway, in the manual it says to make sure I have a 240v rated switch. The
> switch has no rating marked on it so how can I find out if it is ok?
>
> -Steve
>
>
>
Electrical is more of my practical side:
The Switch (A regular switch that is) is ok if you flip it one way and
the motor starts and if you flip it the other way the motor stops.
Here are some symptoms of a under rated switch:
The switch gets hot to the touch
Smoke coming out of the switch
The motor stopped under load and won't start again.
If your switch has a UL or ULC rating, it will have it's ratings usually
on the metal mounting plates. otherwise, I'd invest in another switch.
The RPM's of your motor are not relevant to the switch under normal
conditions.
Hope I can help.
On Fri, 28 Apr 2006 18:25:52 GMT, "CW" <[email protected]> wrote:
>As an aside, LRod, they are no longer teaching it as "E". They now use "V".
>I guess someone decided that is was to hard to remember. Seems I confuse the
>modern electronic types too when I use the term megacycles. :)
You mean back when pico-farads were mickey-mikes?
You won't ever confuse me with those terms. My license dates from
1963.
You know, kilocycle cops never took off in an updated form; kilohertz
cops. I guess ya gotta be a DX'er to understand that one (and you may
be).
--
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.
<<As an aside, LRod, they are no longer teaching it as "E". They now use
"V".
I guess someone decided that is was to hard to remember. >>
You mean Eli is now the Vice Man?
Lee
--
To e-mail, replace "bucketofspam" with "dleegordon"
_________________________________
Lee Gordon
http://www.leegordonproductions.com
In article <[email protected]>, "Toller" <[email protected]> wrote:
>>>The Switch (A regular switch that is) is ok if you flip it one way and
>>>the motor starts and if you flip it the other way the motor stops.
>>
>> False. The switch is ok if that occurs, *and* the switch is rated for both
>> the
>> voltage and the amperage that it's switching. Better still if the switch
>> disconnects all of the hot conductors going to the motor.
>
>Well, that's false also. A switch for a motor has to be rated for the hp of
>the motor. You can be okay on voltage and amperage and still fry the
>switch. It happened on my used table saw; the switch fused closed.
Do you really suppose that the horsepower of a motor is independent of the
voltage and amperage?
--
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] says...
>
> "LRod" <[email protected]> wrote in message
> news:[email protected]...
> > On Thu, 27 Apr 2006 07:55:21 GMT, "Toller" <[email protected]> wrote:
> >>
> >>"Steve W" <[email protected]> wrote in message
> >>news:[email protected]...
> >>>I have a Delta hybrid TS (36-715) and just wired it for 240v. Now the
> >>>thing starts up so fast it makes me worry about belt wear.
> >>>
> >>If it doesn't say on the switch, you can tell by measuring (after the
> >>switch, with the switch on off) the voltage from each wire to ground. If
> >>either is 120v, then it is a 120v switch.
> >>That explains why you need a 240v switch. While the tool works fine
> >>either
> >>way; a 120v switch leaves wire energized that you would expect to be dead.
> >
> > Even a SPST switch is technically capable of switching a 240V device
> > on and off--if any break occurs in the circuit (that is, either leg)
> > the motor will not run. That is what you alluded to. There has been a
> > fair amount of debate here as to whether that's a good idea or not.
> >
> > However, if the switch contacts are only rated for 125V service it's
> > not a good idea to employ the switch for 240V use irrespective of
> > whether it's a SPST or DPST.
> >
> > Now, to answer the OP's question, I would be very surprised if there
> > wasn't any voltage rating marked on the switch. I would have thought
> > that a requirement. In any event, I believe one of the other poster's
> > answer is probably a good idea--contact Delta.
> >
> You are FOS.
> A SPST is not a 240v switch in this country, even if it is rated for 240v.
> If you look at a SPST circuit breaker it says "120/240vac". By your
> reasoning you could use one to protect a 240v circuit. It would work,
>
Take a look at some of the new contactors being used to switch air
conditioning compressors on/off. Some of the new ones only have ONE
contact point, yet they switch 240 VAC on/off all the time. Personally,
I don't like it but it works because current only flows when the two
legs form a circuit. Interrupt either one and you break the circuit.
The same thing would happen if you put a SPST in one of the 240 VAC
legs. I certainly wouldn't suggest that, but it'd work -- for how long
I don't know as the switch contacts might not handle the current load
for very long. My suggestion -- CONTACT DELTA and don't give up until
you talk to someone you trust!
"Steve W" <[email protected]> wrote in message
news:[email protected]...
>I have a Delta hybrid TS (36-715) and just wired it for 240v. Now the
>thing starts up so fast it makes me worry about belt wear.
Typically this is normal as there is less voltage drop when you power up.
> Anyway, in the manual it says to make sure I have a 240v rated switch.
> The switch has no rating marked on it so how can I find out if it is ok?
Replace the switch and while you are at it spend the extra $ and get a
Magnetic 240v switch. If using a magnetic switch and you have an
interruption of power you have to manually turn the saw back on. Handy if
you forget to turn the saw off before the power comes back on.
Toller wrote:
> "Mike Marlow" <[email protected]> wrote in message
> news:[email protected]...
>
>>"Toller" <[email protected]> wrote in message
>>news:[email protected]...
>>
>>>>>The Switch (A regular switch that is) is ok if you flip it one way and
>>>>>the motor starts and if you flip it the other way the motor stops.
>>>>
>>>>False. The switch is ok if that occurs, *and* the switch is rated for
>>
>>both
>>
>>>>the
>>>>voltage and the amperage that it's switching. Better still if the
>>>>switch
>>>>disconnects all of the hot conductors going to the motor.
>>>
>>>Well, that's false also. A switch for a motor has to be rated for the hp
>>
>>of
>>
>>>the motor. You can be okay on voltage and amperage and still fry the
>>>switch. It happened on my used table saw; the switch fused closed.
>>>
>>>
>>
>>Please Toller - go study ohm's law.
>>
>
> Please Mike, go study motors and switches. Motors have properties that are
> not covered by ohm's law. (can you say "impedence"? Can you say "starting
> current"? Didn't think so.)
>
>
Impedance is the resistive value when a capacitor is used in conjunction
to a frequency. in a motor a capacitor is use to lighten the load when
the motor starts and basically does not much afterwards. As I can See
Toller, your not well respected on your comments in this news group.
further more, the others in this newsgroup seem to take what is spoken
and elaborate on it, while your simply trying to knock someone down.
Well if this is your "thing" let it be so, the rest of us will simply
keep on sawing while your trying to make yourself better than others.
I though news groups were to help and discuss issues not to black ball
others????
To the other's, I'd like to present myself, as an electronics hobbies
that also likes wood working. I've been scanning the threads for quite
some times now, "about 9 months" I like the conversations and the good
hearted replies that come from all of you. Keep up the good spirit.
I've learned so much from this newsgroup. Kooda to all.
Roger Bigras.
And my 10Cents for Toller.
Either Ohm's law is
V=IR
or
E=IR
or
P=IV
or
w=IV
In my book, 2X2 = 4 The variable is irrelevant to the equation, If you
know the watts that a horsepower takes, then the rest is MATH.
And as I said!!!!!!!! If the calculations are correct then the switch
will work! Final period. Otherwise Your wasting Your time.
So in the future, If I don't reply to any of your comments, You'll know
why. If you don't, You will when you can figure out E=MC^2
Till Then have fun dissing people.
Roger.
As an aside, LRod, they are no longer teaching it as "E". They now use "V".
I guess someone decided that is was to hard to remember. Seems I confuse the
modern electronic types too when I use the term megacycles. :)
"LRod" <[email protected]> wrote in message
news:[email protected]...
> On Fri, 28 Apr 2006 15:12:51 GMT, "Toller" <[email protected]> wrote:
>
> >>>The Switch (A regular switch that is) is ok if you flip it one way and
> >>>the motor starts and if you flip it the other way the motor stops.
> >>
> >> False. The switch is ok if that occurs, *and* the switch is rated for
both
> >> the
> >> voltage and the amperage that it's switching. Better still if the
switch
> >> disconnects all of the hot conductors going to the motor.
> >
> >Well, that's false also. A switch for a motor has to be rated for the hp
of
> >the motor. You can be okay on voltage and amperage and still fry the
> >switch.
>
> Umm, can you explain that to me? You see, my understanding is that
> voltage is expressed as E. I am also given to understand that amperage
> is expressed as I. I heard once that P (power in watts) is expressed
> as volts times amps, or P=IE. Now here is where it starts to get
> tricky for the uninformed. Power is also expressed as W (for watts)
> and that there are roughly 746 watts per HP (given the givens and
> assuming the assumptions). So, the long and the short of it, as I see
> it, is that there is a direct relationship between amps, volts, and
> hp.
>
> What does that mean for you? Well, if you will simply explain how you
> can be okay on voltage and amperage and still have a problem with the
> hp of the motor, I'll take back everything I've ever said about your
> electrical incompetency. Since CW has summed it up much more
> succinctly than I (that you don't have a clue), you'll be unable to
> and I won't have to eat a single word.
>
> Bottom line: don't give electrical advice. You are so far out of your
> element you are dangerous.
>
>
> >It happened on my used table saw; the switch fused closed.
>
> --
> 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.
Doug Miller wrote:
> In article <[email protected]>, Roger Bigras <[email protected]> wrote:
>
>>Steve W wrote:
>>
>>>I have a Delta hybrid TS (36-715) and just wired it for 240v. Now the thing
>>>starts up so fast it makes me worry about belt wear.
>>>
>>>Anyway, in the manual it says to make sure I have a 240v rated switch. The
>>>switch has no rating marked on it so how can I find out if it is ok?
>>>
>>>-Steve
>>>
>>>
>>>
>>
>>Electrical is more of my practical side:
>>
>>The Switch (A regular switch that is) is ok if you flip it one way and
>>the motor starts and if you flip it the other way the motor stops.
>
>
> False. The switch is ok if that occurs, *and* the switch is rated for both the
> voltage and the amperage that it's switching. Better still if the switch
> disconnects all of the hot conductors going to the motor.
Must agree with the *and* part.
>
>>Here are some symptoms of a under rated switch:
>>The switch gets hot to the touch
>>Smoke coming out of the switch
>>The motor stopped under load and won't start again.
>
>
> If any of those things happen, wouldn't you say the switch was *not* "ok" ?
Yup, in this case *under rated* or *not* would in my understanding
explain that the switch is bad or inadequate.
>
>>The Switch (A regular switch that is) is ok if you flip it one way and
>>the motor starts and if you flip it the other way the motor stops.
>
> False. The switch is ok if that occurs, *and* the switch is rated for both
> the
> voltage and the amperage that it's switching. Better still if the switch
> disconnects all of the hot conductors going to the motor.
Well, that's false also. A switch for a motor has to be rated for the hp of
the motor. You can be okay on voltage and amperage and still fry the
switch. It happened on my used table saw; the switch fused closed.
"LRod" <[email protected]> wrote in message
news:[email protected]...
> On Thu, 27 Apr 2006 07:55:21 GMT, "Toller" <[email protected]> wrote:
>
>>
>>"Steve W" <[email protected]> wrote in message
>>news:[email protected]...
>>>I have a Delta hybrid TS (36-715) and just wired it for 240v. Now the
>>>thing starts up so fast it makes me worry about belt wear.
>>>
>>> Anyway, in the manual it says to make sure I have a 240v rated switch.
>>> The switch has no rating marked on it so how can I find out if it is ok?
>>>
>>A 240v switch opens both wires rather than just one. All my tools say if
>>it
>>is 240v in the manual; if yours warns you to be sure you have a 240v
>>switch,
>>you probably don't.
>>If it doesn't say on the switch, you can tell by measuring (after the
>>switch, with the switch on off) the voltage from each wire to ground. If
>>either is 120v, then it is a 120v switch.
>>That explains why you need a 240v switch. While the tool works fine
>>either
>>way; a 120v switch leaves wire energized that you would expect to be dead.
>
> Please don't give electrical advice.
>
> There is a huge difference between whether a switch is physically
> capable of switching 240V (DPST), and whether the contacts (regardless
> of switch configuration) are rated at 240V.
>
> Even a SPST switch is technically capable of switching a 240V device
> on and off--if any break occurs in the circuit (that is, either leg)
> the motor will not run. That is what you alluded to. There has been a
> fair amount of debate here as to whether that's a good idea or not.
>
> However, if the switch contacts are only rated for 125V service it's
> not a good idea to employ the switch for 240V use irrespective of
> whether it's a SPST or DPST.
>
> Now, to answer the OP's question, I would be very surprised if there
> wasn't any voltage rating marked on the switch. I would have thought
> that a requirement. In any event, I believe one of the other poster's
> answer is probably a good idea--contact Delta.
>
You are FOS.
A SPST is not a 240v switch in this country, even if it is rated for 240v.
If you look at a SPST circuit breaker it says "120/240vac". By your
reasoning you could use one to protect a 240v circuit. It would work,
wouldn't it. Well except that the circuit would still be energized between
the unswitch hot and the switch. There is no debate over it; well, except
between you and another person FOS.
A DPST is a 240v switch; find one on a woodworking machine that isn't rated
for 240v. There is no reason to read the switch, except to see if it opens
both wires.
In fact, a motor switch will handle a larger motor on 240v than on 120v;
didn't you know that?
In short, open both wires good, open one wire bad.
"Steve W" <[email protected]> wrote in message
news:[email protected]...
>
> "Chris Friesen" <[email protected]> wrote in message
> news:[email protected]...
>> Tex wrote:
>>
>>> Take a look at some of the new contactors being used to switch air
>>> conditioning compressors on/off. Some of the new ones only have ONE
>>> contact point, yet they switch 240 VAC on/off all the time. Personally,
>>> I don't like it but it works because current only flows when the two
>>> legs form a circuit.
>>
>> Yes, but it still leaves one of the wires at 120V with respect to ground.
>>
>> With a typical saw setup you could get a nasty shock if you turn off the
>> machine with a single pole switch, then start working on the motor.
>>
>> Of course, for safety I'd unplug the machine anyway before working on it,
>> but still....
>>
>> Chris
>
> Thanks for the help.
>
> I took the switch apart and inside it says it is rated for 250v @ 20a.
> Then I checked both poles with an ohm meter and both open when the switch
> is off. So, it looks like the saw has a DPST 250v switch if I understand
> correctly. It would have been nice if they labeled the outside or manual,
> but it looks like I am good to go so I am happy.
>
I would want to test it with volt meter, though an ohm meter ought to be
okay.
You sound good to go.
I hadn't thought about that until you brought it up. They still teach that
saying, in it's original form. Never occurred to me why so many had such
trouble with it.
"Lee Gordon" <[email protected]> wrote in message
news:[email protected]...
> <<As an aside, LRod, they are no longer teaching it as "E". They now use
> "V".
> I guess someone decided that is was to hard to remember. >>
>
> You mean Eli is now the Vice Man?
>
> Lee
>
> --
> To e-mail, replace "bucketofspam" with "dleegordon"
>
> _________________________________
> Lee Gordon
> http://www.leegordonproductions.com
>
>
On Thu, 27 Apr 2006 07:55:21 GMT, "Toller" <[email protected]> wrote:
>
>"Steve W" <[email protected]> wrote in message
>news:[email protected]...
>>I have a Delta hybrid TS (36-715) and just wired it for 240v. Now the
>>thing starts up so fast it makes me worry about belt wear.
>>
>> Anyway, in the manual it says to make sure I have a 240v rated switch.
>> The switch has no rating marked on it so how can I find out if it is ok?
>>
>A 240v switch opens both wires rather than just one. All my tools say if it
>is 240v in the manual; if yours warns you to be sure you have a 240v switch,
>you probably don't.
>If it doesn't say on the switch, you can tell by measuring (after the
>switch, with the switch on off) the voltage from each wire to ground. If
>either is 120v, then it is a 120v switch.
>That explains why you need a 240v switch. While the tool works fine either
>way; a 120v switch leaves wire energized that you would expect to be dead.
Please don't give electrical advice.
There is a huge difference between whether a switch is physically
capable of switching 240V (DPST), and whether the contacts (regardless
of switch configuration) are rated at 240V.
Even a SPST switch is technically capable of switching a 240V device
on and off--if any break occurs in the circuit (that is, either leg)
the motor will not run. That is what you alluded to. There has been a
fair amount of debate here as to whether that's a good idea or not.
However, if the switch contacts are only rated for 125V service it's
not a good idea to employ the switch for 240V use irrespective of
whether it's a SPST or DPST.
Now, to answer the OP's question, I would be very surprised if there
wasn't any voltage rating marked on the switch. I would have thought
that a requirement. In any event, I believe one of the other poster's
answer is probably a good idea--contact Delta.
--
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.
"Toller" <[email protected]> wrote in message
news:[email protected]...
> >>The Switch (A regular switch that is) is ok if you flip it one way and
> >>the motor starts and if you flip it the other way the motor stops.
> >
> > False. The switch is ok if that occurs, *and* the switch is rated for
both
> > the
> > voltage and the amperage that it's switching. Better still if the switch
> > disconnects all of the hot conductors going to the motor.
>
> Well, that's false also. A switch for a motor has to be rated for the hp
of
> the motor. You can be okay on voltage and amperage and still fry the
> switch. It happened on my used table saw; the switch fused closed.
>
>
Please Toller - go study ohm's law.
--
-Mike-
[email protected]
"Toller" <[email protected]> wrote in message
news:[email protected]...
>
> "Mike Marlow" <[email protected]> wrote in message
> news:[email protected]...
> >
> > "Toller" <[email protected]> wrote in message
> > news:[email protected]...
> >> >>The Switch (A regular switch that is) is ok if you flip it one way
and
> >> >>the motor starts and if you flip it the other way the motor stops.
> >> >
> >> > False. The switch is ok if that occurs, *and* the switch is rated for
> > both
> >> > the
> >> > voltage and the amperage that it's switching. Better still if the
> >> > switch
> >> > disconnects all of the hot conductors going to the motor.
> >>
> >> Well, that's false also. A switch for a motor has to be rated for the
hp
> > of
> >> the motor. You can be okay on voltage and amperage and still fry the
> >> switch. It happened on my used table saw; the switch fused closed.
> >>
> >>
> >
> > Please Toller - go study ohm's law.
> >
> Please Mike, go study motors and switches. Motors have properties that
are
> not covered by ohm's law. (can you say "impedence"? Can you say
"starting
> current"? Didn't think so.)
>
>
At the risk of sounding repetitive...
While you're studying this stuff, don't be surprised to find that ohm's law
well covers those issues.
You're throwing out a bunch of terms that have meaning but they do nothing
to support your case. If you understood ohm's law and other principles of
electricity you'd know the folly of your statement. Electrical discussion
haven't been your strong suit here - I can't help but wonder why you step
into this same trap time and time again.
--
-Mike-
[email protected]
"CW" <[email protected]> wrote in message
news:[email protected]...
> As an aside, LRod, they are no longer teaching it as "E". They now use
"V".
> I guess someone decided that is was to hard to remember. Seems I confuse
the
> modern electronic types too when I use the term megacycles. :)
>
Megacycles - those are the big cycles, right? The really big cycles.
--
-Mike-
[email protected]
In article <[email protected]>, [email protected]
says...
> Tex wrote:
>
> > Take a look at some of the new contactors being used to switch air
> > conditioning compressors on/off. Some of the new ones only have ONE
> > contact point, yet they switch 240 VAC on/off all the time. Personally,
> > I don't like it but it works because current only flows when the two
> > legs form a circuit.
>
> Yes, but it still leaves one of the wires at 120V with respect to ground.
>
> With a typical saw setup you could get a nasty shock if you turn off the
> machine with a single pole switch, then start working on the motor.
>
> Of course, for safety I'd unplug the machine anyway before working on
> it, but still....
>
> Chris
>
Yes, that's why I don't like it. I guess at an a.c. compressor it's
pretty isolated and not that much a danger. But, technically, "it sure
ain't pretty" I realize it's cheap (in all respects to use of that term
including, but not limited to, less expensive). So, to each his own -
I'll buy something better.
Also, I wouldn't advocate switching ONLY one leg, particularly one where
someone might, by whatever means, come into contact with a live 120 VAC
leg on the downside of that switch. I admit I haven't checked the NEC
to see where/when this is allowed/disallowed -- I just don't like it on
esoteric/technical grounds.
On unplugging the machine -- I NEVER even change a blade without
unplugging the connection. And, I have a 240 VAC magnetic switch
between on/off.
For me, with power tools and firearms there just "ain't no way to be too
safe"!
"Mike Marlow" <[email protected]> wrote in message
news:[email protected]...
>
> "Toller" <[email protected]> wrote in message
> news:[email protected]...
>> >>The Switch (A regular switch that is) is ok if you flip it one way and
>> >>the motor starts and if you flip it the other way the motor stops.
>> >
>> > False. The switch is ok if that occurs, *and* the switch is rated for
> both
>> > the
>> > voltage and the amperage that it's switching. Better still if the
>> > switch
>> > disconnects all of the hot conductors going to the motor.
>>
>> Well, that's false also. A switch for a motor has to be rated for the hp
> of
>> the motor. You can be okay on voltage and amperage and still fry the
>> switch. It happened on my used table saw; the switch fused closed.
>>
>>
>
> Please Toller - go study ohm's law.
>
Please Mike, go study motors and switches. Motors have properties that are
not covered by ohm's law. (can you say "impedence"? Can you say "starting
current"? Didn't think so.)
Call Delta with all model numbers in hand is the best advice . . . As to
switches, somewhere they are marked, may be criptic, but marked. As to
switch safety . . . AMP rating is what you are most concerned with . . .
AMPS ! ! !
Steve
"Steve W" <[email protected]> wrote in message
news:[email protected]...
> I have a Delta hybrid TS (36-715) and just wired it for 240v. Now the
thing
> starts up so fast it makes me worry about belt wear.
>
> Anyway, in the manual it says to make sure I have a 240v rated switch.
The
> switch has no rating marked on it so how can I find out if it is ok?
>
> -Steve
>
>
>
On Fri, 28 Apr 2006 15:12:51 GMT, "Toller" <[email protected]> wrote:
>>>The Switch (A regular switch that is) is ok if you flip it one way and
>>>the motor starts and if you flip it the other way the motor stops.
>>
>> False. The switch is ok if that occurs, *and* the switch is rated for both
>> the
>> voltage and the amperage that it's switching. Better still if the switch
>> disconnects all of the hot conductors going to the motor.
>
>Well, that's false also. A switch for a motor has to be rated for the hp of
>the motor. You can be okay on voltage and amperage and still fry the
>switch.
Umm, can you explain that to me? You see, my understanding is that
voltage is expressed as E. I am also given to understand that amperage
is expressed as I. I heard once that P (power in watts) is expressed
as volts times amps, or P=IE. Now here is where it starts to get
tricky for the uninformed. Power is also expressed as W (for watts)
and that there are roughly 746 watts per HP (given the givens and
assuming the assumptions). So, the long and the short of it, as I see
it, is that there is a direct relationship between amps, volts, and
hp.
What does that mean for you? Well, if you will simply explain how you
can be okay on voltage and amperage and still have a problem with the
hp of the motor, I'll take back everything I've ever said about your
electrical incompetency. Since CW has summed it up much more
succinctly than I (that you don't have a clue), you'll be unable to
and I won't have to eat a single word.
Bottom line: don't give electrical advice. You are so far out of your
element you are dangerous.
>It happened on my used table saw; the switch fused closed.
--
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.
On Fri, 28 Apr 2006 01:47:42 GMT, "CW" <[email protected]> wrote:
>If you expected to seem credible, you just blew it. Toller normal.
He blew credible in his first post, but then he always does in any
thread about electricity.
>"Toller" <[email protected]> wrote in message
>news:[email protected]...
>> >
>> I would want to test it with volt meter, though an ohm meter ought to be
>> okay.
>> You sound good to go.
>>
>>
>
--
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]>, Roger Bigras <[email protected]> wrote:
>Steve W wrote:
>> I have a Delta hybrid TS (36-715) and just wired it for 240v. Now the thing
>> starts up so fast it makes me worry about belt wear.
>>
>> Anyway, in the manual it says to make sure I have a 240v rated switch. The
>> switch has no rating marked on it so how can I find out if it is ok?
>>
>> -Steve
>>
>>
>>
>Electrical is more of my practical side:
>
>The Switch (A regular switch that is) is ok if you flip it one way and
>the motor starts and if you flip it the other way the motor stops.
False. The switch is ok if that occurs, *and* the switch is rated for both the
voltage and the amperage that it's switching. Better still if the switch
disconnects all of the hot conductors going to the motor.
>
>Here are some symptoms of a under rated switch:
>The switch gets hot to the touch
>Smoke coming out of the switch
>The motor stopped under load and won't start again.
If any of those things happen, wouldn't you say the switch was *not* "ok" ?
--
Regards,
Doug Miller (alphageek at milmac dot com)
It's time to throw all their damned tea in the harbor again.
On Thu, 27 Apr 2006 13:24:41 GMT, "Toller" <[email protected]> wrote:
>
>"LRod" <[email protected]> wrote in message
>news:[email protected]...
>> On Thu, 27 Apr 2006 07:55:21 GMT, "Toller" <[email protected]> wrote:
>>
>>>
>>>"Steve W" <[email protected]> wrote in message
>>>news:[email protected]...
>>>>I have a Delta hybrid TS (36-715) and just wired it for 240v. Now the
>>>>thing starts up so fast it makes me worry about belt wear.
>>>>
>>>> Anyway, in the manual it says to make sure I have a 240v rated switch.
>>>> The switch has no rating marked on it so how can I find out if it is ok?
>>>>
>>>A 240v switch opens both wires rather than just one. All my tools say if
>>>it
>>>is 240v in the manual; if yours warns you to be sure you have a 240v
>>>switch,
>>>you probably don't.
>>>If it doesn't say on the switch, you can tell by measuring (after the
>>>switch, with the switch on off) the voltage from each wire to ground. If
>>>either is 120v, then it is a 120v switch.
>>>That explains why you need a 240v switch. While the tool works fine
>>>either
>>>way; a 120v switch leaves wire energized that you would expect to be dead.
>>
>> Please don't give electrical advice.
>>
>> There is a huge difference between whether a switch is physically
>> capable of switching 240V (DPST), and whether the contacts (regardless
>> of switch configuration) are rated at 240V.
>>
>> Even a SPST switch is technically capable of switching a 240V device
>> on and off--if any break occurs in the circuit (that is, either leg)
>> the motor will not run. That is what you alluded to. There has been a
>> fair amount of debate here as to whether that's a good idea or not.
>>
>> However, if the switch contacts are only rated for 125V service it's
>> not a good idea to employ the switch for 240V use irrespective of
>> whether it's a SPST or DPST.
>>
>> Now, to answer the OP's question, I would be very surprised if there
>> wasn't any voltage rating marked on the switch. I would have thought
>> that a requirement. In any event, I believe one of the other poster's
>> answer is probably a good idea--contact Delta.
>>
>You are FOS.
Really? Let's review:
>A SPST is not a 240v switch in this country, even if it is rated for 240v.
Huh? In this country (which country is that, by the way? Do you even
know where I live?) I'm pretty sure I can switch 240V with a SPST
switch (assuming it's rated for 240V). The test might be "does the
motor work when I switch one leg of the two pole, single phase
electrical service" which would absolutely not be true. Of course I
could also be switching a 240V plate supply in a vacuum tube circuit,
in which case a SPST switch is all I'd ever need.
>If you look at a SPST circuit breaker it says "120/240vac". By your
>reasoning you could use one to protect a 240v circuit. It would work,
>wouldn't it.
Huh? Who said anything about circuit breakers? I certainly didn't.
>Well except that the circuit would still be energized between
>the unswitch hot and the switch. There is no debate over it; well, except
>between you and another person FOS.
In any circuit, if it is interrupted, it will no longer work. That's
dirt simple, fundamental electronics. You seem unable to even grasp
that.
>A DPST is a 240v switch;
Really? That's the first I've ever heard that. That will certainly
save UL and a whole lot of other people a bunch of work testing switch
dilectrics for voltage capacity.
>...find one on a woodworking machine that isn't rated
>for 240v. There is no reason to read the switch, except to see if it opens
>both wires.
Huh? So you're saying that when you want to change a dual voltage
motor from 120V to 240V and the owner's manual says "make sure you
have a 240v rated switch," your solution is to just fire it up and go.
You don't feel any need to check to see if the switch is rated at
240V. Worse, you somehow feel the need to propagate that
irresponsibility to innocent users who haven't as yet had a chance to
witness your electrical incompetency over a period of time.
>In fact, a motor switch will handle a larger motor on 240v than on 120v;
>didn't you know that?
Huh? What does that have to do with the OP's question?
>In short, open both wires good, open one wire bad.
But not illegal. Intuitively (and solely from the safety standpoint),
I would prefer to switch both legs, but I don't believe it's necessary
(and it isn't necessary from an electrical standpoint).
So, in the final analysis, in regard to your statement:
>You are FOS.
I can only point out the obvious and say PKB.
Don't you get tired of embarrassing yourself? Stay out of electrical
discussions and you will reduce your vulnerability 100 fold. You
haven't a clue as to what your're talking about--just a few buzz words
you throw together like monkeys at typewriters.
--
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.
"Steve W" <[email protected]> wrote in message
news:[email protected]...
>I have a Delta hybrid TS (36-715) and just wired it for 240v. Now the
>thing starts up so fast it makes me worry about belt wear.
>
> Anyway, in the manual it says to make sure I have a 240v rated switch.
> The switch has no rating marked on it so how can I find out if it is ok?
>
A 240v switch opens both wires rather than just one. All my tools say if it
is 240v in the manual; if yours warns you to be sure you have a 240v switch,
you probably don't.
If it doesn't say on the switch, you can tell by measuring (after the
switch, with the switch on off) the voltage from each wire to ground. If
either is 120v, then it is a 120v switch.
That explains why you need a 240v switch. While the tool works fine either
way; a 120v switch leaves wire energized that you would expect to be dead.
"Chris Friesen" <[email protected]> wrote in message
news:[email protected]...
> Tex wrote:
>
>> Take a look at some of the new contactors being used to switch air
>> conditioning compressors on/off. Some of the new ones only have ONE
>> contact point, yet they switch 240 VAC on/off all the time. Personally,
>> I don't like it but it works because current only flows when the two legs
>> form a circuit.
>
> Yes, but it still leaves one of the wires at 120V with respect to ground.
>
> With a typical saw setup you could get a nasty shock if you turn off the
> machine with a single pole switch, then start working on the motor.
>
> Of course, for safety I'd unplug the machine anyway before working on it,
> but still....
>
> Chris
Thanks for the help.
I took the switch apart and inside it says it is rated for 250v @ 20a. Then
I checked both poles with an ohm meter and both open when the switch is off.
So, it looks like the saw has a DPST 250v switch if I understand correctly.
It would have been nice if they labeled the outside or manual, but it looks
like I am good to go so I am happy.
-Steve
[email protected] (Doug Miller) writes:
>In article <[email protected]>, "Toller" <[email protected]> wrote:
>>>>The Switch (A regular switch that is) is ok if you flip it one way and
>>>>the motor starts and if you flip it the other way the motor stops.
>>>
>>> False. The switch is ok if that occurs, *and* the switch is rated for both
>>> the
>>> voltage and the amperage that it's switching. Better still if the switch
>>> disconnects all of the hot conductors going to the motor.
>>
>>Well, that's false also. A switch for a motor has to be rated for the hp of
>>the motor. You can be okay on voltage and amperage and still fry the
>>switch. It happened on my used table saw; the switch fused closed.
>
>Do you really suppose that the horsepower of a motor is independent of the
>voltage and amperage?
At sears, yes.
scott :-)