Outlet/Plug for 240volt, single phase, 20amp lathe

[Dick in Wisconsin]

Bought an old South Bend 4x10L lathe (catalog #8187A). Guy I bought it from thought he bought it 25 years ago from a job shop in Milwaukee. Doesn't know how old it is, I'm guess 1940's/50's ... maybe a touch older.

He told me it was 240volt, single phase, 20amp motor. He had it plugged into the garage next to his house ... so I believe the single phase part is solid.

He had it plugged into the twist lock outlet shown in the picture. I went to home depot and bought a 240volt, single phase, 20 amp outlet (NEMA L6-20A). But the old plug wouldn't fit in the new outlet. The "L" on one of the prongs of the old plug points to the outside of the circle and the "L" on the new outlet points to the inside.

It's a three wire set up; the cord to the lathe has single black, white, and green wires. I presume (I'm not an electrician) two hots (black and white) and a single ground or neutral, green).

Rummaging around in Google I found "NEMA wiki" which led me to the Hubbell catalog. In there I found a NEMA L7-20P (20A 277V AC) outlet/plug configuration which has the "L" of a prong pointing to the outside of the circle. I wonder if this was the plug/outlet that was originally used?

Has the configuration of these plugs changed over time? Was the lathe (in the industrial setting) originally wired for a NEMA L7-20P plug and hence outlet?

So ... my question is ... can I use a NEMA L6-20 plug and outlet? I have 12-3 wire (black, red, white, and bare copper ground) coming to the outlet for the lathe that will be wired into the panel by a real electrician. My plan is to not use the bare copper ground wire. From the service panel, black and red will be hots, white will be the ground(?).

Wire from Lathe .... wire to service panel
Green (ground?) ... white
Black (hot) ... black (hot)
White (hot) ... red (hot)

Question about direction of relation of the motor. Does it make any difference how the motor is wired regarding the direction of rotation?

Are my assumptions correct? I'll have this double checked by the electrician when he wires everything to the service panel.

 

[pattenp]

You need to use the bare for the ground. White is not to be designated as a ground.

 

[Dick in Wisconsin]

You need to use the bare for the ground. White is not to be designated as a ground.

Ahhhh. Thank you so much!

Then I wouldn't use the white. Red and Black hot, bare copper for the ground.

 

[abk241]

You should really confirm motor voltage and current draw on the nameplate first.

 

[Aceman]

The very first thing you need to check is the motor HP from it's nameplate. This will help size the proper cord end and recep.

 

[Dick in Wisconsin]

Now this wasn't easy. The motor is inside the lathe, down near the floor, behind a small door, and the motor data plate faces the floor. Luckily for two things: the lathe is still on furniture dollies and I have an iPhone. The iPhone took a three picture burst and only one of the three is in focus enough too see.

The motor is a Leeson.
Volt: 115/208-230
Amp: 14/7
Phase: 1
Cy: 60
RPM: 1725

I hope this helps you guys help me! Thanks!

 

[Cmreschke]

Looks single phase to me. You can use either twist lock or standard 240 volt receptacle just get a matching set and change the plug on the end of the cord. Do not use a standard 120 volt receptacle.

 

[nadogail]

With a used machine you are not guaranteed that even though you saw it operate, the seller used the correct materials to hook it up.

He may have used was something he had that was "good enough" to make it work.

There are things in my shop that some would take exception to how it is wired up, but it works and is safe.

 

[Aceman]

For that 240V lathe using a twistlock, I'd be looking at a Leviton 2320 L6-20R and a Leviton 2321 L6-20P. Rated for 2HP.

 

[homebuilt burner]

Nice lathe

 

[Dick in Wisconsin]

With a used machine you are not guaranteed that even though you saw it operate, the seller used the correct materials to hook it up. He may have used was something he had that was "good enough" to make it work.

Very good point. No need to repeat a wrong!

For that 240V lathe using a twistlock, I'd be looking at a Leviton 2320 L6-20R and a Leviton 2321 L6-20P. Rated for 2HP.

I have LeGrand/Pass & Seymour componets L620PCCV3 plug and L620RCCV3 receptacle. Both indicate NEMA L6-20R & L6-20P.

Nice lathe

Thanks! I'm excited to get it going. Wanted a lathe for a long time, resigned myself that I end up with something much less, and am pleased to have been able to buy it.

Questions on the wiring:

1. The cord on the lathe has three wires ... black, white, and green (I presume green is ground and the black and white are hot 120volt, I'll remove the plate on the motor where the wiring goes in to confirm that).

2. I used 12-3 (black, red, and white with a bare ground wire) from the panel to the lathe outlet.

3. A poster above said I should not use the white wire for a ground; use the bare copper wire for the ground.

4. So wiring panel to lathe, I plan on:

A. Black to black.
B. Red to white.
C. Bare copper to green.
D. Not use the white wire coming from the panel.

Would this be a correct way to wire it?

Does how the lathe motor is wired determine the direction of the motor? I don't think so, but I want to confirm that.

Thanks for all the help!

 

[pattenp]

Your wiring is correct. Just leave the white in the circuit from panel to outlet unused. You can wirenut off on both ends. The two hot's don't make a difference in the motor rotation based on how they're wired at the outlet or plug. Rotation is control internally by wiring in the motor if shown on the motor diagram/plate.

 

[Dick in Wisconsin]

Your wiring is correct. Just leave the white in the circuit from panel to outlet unused. You can wirenut off on both ends. The two hot's don't make a difference in the motor rotation based on how they're wired at the outlet or plug. Rotation is control internally by wiring in the motor if shown on the motor diagram/plate.

So if it turned in the right direction for the previous owner, it should turn in the right direction for me.

Confirm. Thanks!

 

[pattenp]

So if it turned in the right direction for the previous owner, it should turn in the right direction for me.

Confirm. Thanks!

It better turn in the same direction as it did for the previous owner. If it doesn't I'm sure we'll hear from you.

 

[BD1]

You could hard wire to a fused disconnect too.

 

[Dick in Wisconsin]

It better turn in the same direction as it did for the previous owner. If it doesn't I'm sure we'll hear from you.

You could hard wire to a fused disconnect too.

I thought about that, but this gives me flexibility in case I need it.

 

[ExxWhy]

That name plate says it will run on 115 or 230. Seems like there should be a diagram on there someplace to say how to wire it for either voltage. Are you definitely sure it was hooked up to 240 in the old location?

 

[Dick in Wisconsin]

That name plate says it will run on 115 or 230. Seems like there should be a diagram on there someplace to say how to wire it for either voltage. Are you definitely sure it was hooked up to 240 in the old location?

The previous owner was very emphatic about that. The ancient receptacle said 20amp/240volt ... which I realize might NOT coincide with how it was actually wired.

You're making a good point. I'll pull the cover off the motor's electrical connection and confirm how its wired.