Wiring PM lathe 220v ?

If possible, you should replace the recepticle, like Roy said.
Hopefully the original installer ran something like 10/3 wire to it.
That means that it should have black, white, red, and bare (or green)
wires. Then, it's a simple switch-over to put in a four-prong
recepticle like a NEMA 6-20; just wire as the directions show. Then
connect green from your pigtail to the ground terminal on the
four-prong plug, and connect white and black where the directions say
to put red and black. The neutral terminal on the plug will have no
connection (even though the directions will probably say to connect the
white wire there).

However, given that there's only a 3-prong outlet now, there's a
reasonable chance that the installer only ran 10/2 (white, black, and
bare) to it. In that case, the RIGHT thing to do is to rerun 10/3 or
12/3 wire from the box, but that's a huge pain. It's very unlikely
that your lathe requires a neutral connection (and if it did, one would
hope that their supplied pigtail would have black, red, white, and
green). So if you're one to take shortcuts, keep your three-prong plug
and connect the green wire to the L-shaped prong, and the white and
black to the slanted prongs. The neutral should technically be
grounded back at your main panel.

If you really want to be sure, using a multimeter (sometimes called a
VOM), you should be able to measure a short circuit between the green
wire and any exposed metal on your lathe (thus verifying that the green
is, indeed, ground), and some relatively low resistance (maybe
somewhere between 0.5 and 5 ohms) between the white and black wires.
There should be an open circuit (very high resistance) between the
green and either of the other two.

Josh

"Roy Fek" <[email protected]> wrote in message
news:[email protected]...
> Hello,
>
> I just received today a Powermatic 3520b lathe. It came wired with a
> pigtail but no plug. The pigtail has three wires - black, white and
> green. The lathe operates on 220v and I have a 220v outlet in the
> garage. The outlet has three "openings", sorry, I don't know the right
> term. Two of the openings are slanted and the third is "L" shaped. I've
> seen this kind of outlet/plug on clothes dryers.
>
http://www.leviton.com/sections/techsupp/nema.htm

You should be using a 6-20. (How many amps is the lathe?) You are probably
using 10-30, you are reusing an old dry outlet and there is a 30a 240v
breaker on it, right?

I would replace the breaker and outlet, and get the right plug.
Other people would say that was a waste of money. They would just connect
the ground of the lathe to the neutral on the plug and use it that way. But
you are right, the green is ground and would go where the neutral is
supposed to go, the two hots going to the blades.
The 10-30 is made for two hots and a neutral, hence the non-grounded
circuit. Since your lathe does not have a neutral (or so I am assuming;
best check that....) you can use the neutral for your ground.
I am also assuming this it going to a panel, rather than a subpanel. The
neutral and ground go to the same place on the panel, but not on the
subpanel.



> I want to power the lathe via this outlet and so I bought a plug to
> match from Home Depot. The instructions for the plug say "Caution: this
> device is not for grounding use. Connect to non-grounding circuits
> only, unless it is to be used for a range or clothes dryer." It also
> states that the white lead should be attach/screwed to the "L" shaped
> blade and the other two remaining wires, I'm left with black and green,
> should be attached to the two slanted blades.
>
> Is this going to work? I thought the two slanted blades were hot and
> the "L" neutral. So, attaching my green wire to one of the slanted
> blades doesn't sound right. Where's my ground? Do I need a Different
> kind of outlet/plug?
>
> Any help would be MUCH appreciated!!!
> Thanks,
> Roy Fek
>