220 V table saws and ground

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I realize this isn't exactly a woodworking question, but when I asked about 220 V wiring for my shed in an earlier thread a lot of electricians came out of the 'woodwork'.
So. I now have 220 V in my shed for my Walker Turner table saw. I noticed that the plug from the saw only has two wires. The ground is not connected. My shed has a ground stake. Should I run the ground wire to the saw? It certainly has a whooping iron chasis. Should I not do this?
(For those of you who helped me the last time, I finally decided to get an electrician to wire it. He took the 220V line from my 30 amp circuit for the house drier (I have a gas drier, so I don't use it), ran #10 wires out to a 30 amp breaker panel in the shed, split out two 110V circuits and a 20 amp 220v and put in a ground stake. This took him 6 hours. It would have taken me about 2 months).
thanks, b
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On Mon, 07 Dec 2009 23:28:28 -0800, sibosop wrote:

A ground is never a bad idea. I would add one. I am not familiar with that TS, so not sure how you would add it. Sure someone here can give you some help with adding the ground.
Paul T.
--
The only dumb question, is the one not asked

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I AM NO ELECTRICIAN
But I wired my 220 TS 10 years ago. Mine has 3 wires. 2 leads and a neutral, not a ground. Are you sure yours is not wired for 110? From what I understand more modern wiring set ups are 4 wire. 2 leads, a neutral and a ground.
Might want to consult a qualified electrician on the matter.
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Leon wrote: ...

No, there is no neutral for a 220 (US, not Brit); the third conductgor is a ground. You're confusing the use of the ground as neutral for the 110V circuit of a 3-wire dual voltage hookup (electric range range/dryer for example) as making it a neutral--it isn't.

Again, that's only for dual-use--the TS doesn't have the 110V load so no need. Recent NEC requires the neutral rather than shared but again there's no neutral for 220V only.

OP did have the circuit run by an electrician he says -- as somebody else noted, all he needs is a 3-wire cordset to update the old 2-wire one in the most convenient manner to add the ground.
--
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That is right. You only need a neutral when you need dual voltage as in a dryer or stove. 240V (no longer 220 volt) only equipment such as motors only need the two hot wires and a ground. Use the specific plug and receptical for 240 volt and the rated amperage, better still, use a twist lock plug and receptical (again the correct type for the voltage and amperage) if the wire trails across the floor so that it doesn't get pulled out.
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EXT wrote: ...

I just kept w/ Leon's values -- there's really ime no telling what any given locale will be running as actual voltages...
The motor only "needs" the two hots if you're going to get into "needs" (as the fact OP's running it currently on the 2-wire cordset shows). :)
/No, I _couldn't_ help myself now, could I? :)/
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OKay. Thanks everybody. The way it is now is that there is a long extension cord (two wire with ground) going to a short cord from the saw (two wire). I can just replace the two wire cord with a three wire and hook the ground to some appropriate piece of iron on the saw top.
b
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sibosop wrote: ...

I'd _strongly_ suggest (and maybe it's what you're saying) get rid of the extension cord entirely and put an appropriately-sized cord on the saw that is sufficient in length.
As for the ground connection, there should be a suitable grounding location in the box where the cord is attached on the machine or very near there that would be suitable and make for a neat installation.
Again, note that the ground conductor is simply that -- it serves no operational electrical function; it's only a safety ground.
--
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That's not quite complete; you MUST connect the ground wire to the box with the on/off switch, and the frame of the motor, and you can then (if you want) bond the motor or switch to the tablesaw top and/or frame.
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Ok. Thank you. Switch, Motor Switch. Motor. Switch. Motor b
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sibosop wrote:

In _very_ high likelihood those bondings are already done w/ the mounting but never hurts to check or run a separate. Logically, while you're at it you would run 3-wire from the switch to the motor at the same time you're doing the rest and tie the grounds together.
--
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On Tue, 8 Dec 2009 10:22:32 -0800 (PST), the infamous sibosop

IANAE, but I'd ground the _motor_ if I were you, not the top. The top isn't electrified. ;)
I did all my own 240v wiring in this shop (with attached house), then ran 25' cords from each of the tools to the wall outlets. I can move them around any way I like, any time I like. It's all 12/3 going to the outlets and 12/3 cordage, with NEMA L6-20 twistlocks.
Dina came with a whoopass 10/3 cable (thicker than my thumb.) The Griz G1012 BS and Griz G1029 DC are each 2hp, so 12/3 has plenty of current handling capability.
-- To know what you prefer instead of humbly saying Amen to what the world tells you you ought to prefer, is to have kept your soul alive. -- Robert Louis Stevenson
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Snip
Hey It is hard to tell what the voltage is any more. LOL. 2 weeks ago "after" having 3 new leads run underground to my home, I lost electricity in 1/2 of my house and had no 240? ;!) I started having issues with lights diming.
I used a volt meter to check the voltage on the side of the house that I had previousely been dead and got 105 volts on about half the recepticals. The other half showed 138 volts.
The common neutral that was dedicated to my house and 3 neighbors had rusted and was causing the dimming problem for all of us. The light company came out and replaced the "thang" that attached the neutrals to the 4 houses.
Every thing went back to 122 volts after the repair.
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Leon wrote: ...

Bad neutral is different that my reference altho can be entertaining set of symptoms (unfortunately, which may also turn into expensive)...
I've seen "normal" anywhere from 107V - 130V as pretty common just depending on where on a line and how far from distribution transformer a run is. Perhaps not as much variation common in residential/metro areas that don't cover such long distances w/ individual or very few loads as see out here...
...
BTW, on that 240V circuit, I'd presume it is more than likely ok but it might not hurt to double check did actually hook the ground conductor to the ground buss in the box rather than to the neutral buss if really were thinking neutral as opposed to ground way back then...nothing is going to happen but it really ought to be on ground, not neutral per Code.
--
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"dpb" wrote:

Years ago, NEMA standardized on voltage ratings as follows:
Distribution devices such as transformers and circuit breakers:
120VAC and multiples there of.
Utilization devices such as motors and heating equipment:
115VAC and multiples there of.
The 5VAC differential accomodates line losses and calculation of loads.
Lew
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Lew Hodgett wrote: ...

That's theory; I'm talking observed...again, may be better in less rural areas.
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"dpb" wrote:

Theory hell, that's just the way it has been for over 30 years.
Measured values at any point in the system are not relavent to a rating standard.
Lew
Lew
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Lew Hodgett wrote:

Other than I wasn't speaking of them but referring to measured... :)
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scrawled the following:

That's true. Local companies adjust transformers so the voltage at most outlets is going to be that nominal 120v. If you have a lot of heavy users on your particular transformer, the normal voltage will run high to compensate during those times the heavy users are using heavily. Capice?
-- To know what you prefer instead of humbly saying Amen to what the world tells you you ought to prefer, is to have kept your soul alive. -- Robert Louis Stevenson
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Nope. The transformers at the substation have tap changers (works like a voltage regulator) to maintain the voltage as close as possible under varying load. As there are a finite number of taps, the voltage my vary a bit.
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