Double Check me PLEASE

[Mike Davis]

I installed a 220V outlet in my shop today and I'd like a second check to be sure I got it right.

After i flipped the breaker and nothing went kablooie I checked the voltage at the outlet.

The numbers are what my volt meter read and the colors are the wire color.

Does this look right to you?

 

[FredP]

looks right to me. red and black are hot 125 each white is neutral and bare wire is ground from what I see ya dun gud! but get a second opinion please.....:gar-Bi

 

[steviegwood]

As long as if you have 240v between the black and red it is correct but it could be possible to get the readings that you have and still only have 125v to the outlet unless the other end is attached to a double pole breaker. You could get your readings and have the red and black coming from the same leg. I hope that makes sense. Steve

 

[fergy]

As long as if you have 240v between the black and red it is correct but it could be possible to get the readings that you have and still only have 125v to the outlet unless the other end is attached to a double pole breaker. You could get your readings and have the red and black coming from the same leg. I hope that makes sense. Steve

If he's getting a reading of 245V between red and black he's on two different phases. No other way to get that reading.

You look good to go. The only other thing I meter is between ground and neutral, just to make sure it's 0. If not, somethings up.

 

[Mike Davis]

Yes, that makes sense Steve. I did put in a new 20 amp 220V double breaker and made sure that each leg goes to a separate input.

So, the next step is to put a plug on the motor wire and see if it goes round and round!

Maybe some pics later.

 

[Mike Davis]

AHH ha! :slap: me.

Thanks Fergy, I didn't think to check ground to neutral.

 

[Joe Scharle]

Fred's got it...
Now measure between neutral & gnd to make sure there's no floating gnd. You're looking for zero.

 

[Mike Davis]

0.456 V

And I get the same reading in the house on my 125V outlets and on my dryer outlet.

So, does that mean I have a ground fault in the house somewhere?

I checked the meter and get 0.000 when i touch the leads directly together.

 

[fergy]

You're fine with that voltage between neutral and ground. That's just induction being caused by electrical motors and other, for lack of better words, "leaky" electrical stuff. You'd only notice it if you had a recording studio in your house or were an audiophile. Actually, induction isn't the righ term, but you get the idea.

 

[steviegwood]

If he's getting a reading of 245V between red and black he's on two different phases. No other way to get that reading.

You look good to go. The only other thing I meter is between ground and neutral, just to make sure it's 0. If not, somethings up.

DUH!!! I completely missed the 245v reading in the drawing. I looked at all of the readings around the circuit and missed the middle. The eyes and brain just ain't what they used to be. Steve :eusa_doh::eusa_doh::eusa_doh:

 

[Alan in Little Washington]

That is an L14-20R receptacle. You have the ground (bare copper) and the neutral (white) reversed. And yes it does make a difference!!!!! Especially if the machine connected to it has a 120V component.

I have a question- why are you using a 4-prong outlet?

Does the 220V equipment that will plug in there have a 120V component? If not, you only need a three prong outlet- two hots and a ground. A neutral is not needed. Four prong outlets are more expensive than three and other than the case I mentioned, not needed. Most equipment that comes with a 220V plug like my Unisaw have a 3 prong molded plug either a 6-15P (15 amp) or a 6-20P (20 amp).

See here for the NEMA plug configurations.

If you wanted to use twist-loc plugs, depending on the rating of the outlet I would have used a NEMA L6-20R (20 amp) or a L6-30R (30 amp), both 3 prong.

 

[fergy]

Ah, good catch. I didn't see that as a receptacle, just a wiring diagram. I missed the key on the neutral.

That is an L14-20R receptacle. You have the ground (bare copper) and the neutral (white) reversed. And yes it does make a difference!!!!! Especially if the machine connected to it has a 120V component.

I have a question- why are you using a 4-prong outlet?

Does the 220V equipment that will plug in there have a 120V component? If not, you only need a three prong outlet- two hots and a ground. A neutral is not needed. Four prong outlets are more expensive than three and other than the case I mentioned, not needed. Most equipment that comes with a 220V plug like my Unisaw have a 3 prong molded plug either a 6-15P (15 amp) or a 6-20P (20 amp).

See here for the NEMA plug configurations.

If you wanted to use twist-loc plugs, depending on the rating of the outlet I would have used a NEMA L6-20R (20 amp) or a L6-30R (30 amp), both 3 prong.

 

[Mike Davis]

Well, I guess I wasted a little money three years ago when I bought the receptacle and matching plug at Lowes and the guy there steered me wrong. I also got 10-3 wire with ground which I probably didn't need.

I have the wires switched now and all is well.

I bought a variable speed set up including 1.5 hp 3 phase inverter duty motor, 2 hp controller with remote switch and pot. I got a real deal on the package and would rather not reveal my source unless he wants to tell the story. (Thanks Brother! :icon_thum ) It came to me completely wired and programmed except for the end plug.

So, I just bench tested it and it runs great, very quiet, slow start, great torque even at the very low end. I've already warned Collin not to run it below 20 percent of power. I'll have to make a red zone on the face plate.

I still have to drill my lathe mount to fit the motor and build a case for the controller. I think I have an old computer tape drive case from the 90s around here somewhere. That should work fine for a dust cover.

Oh, and I have to buy a new step pulley for the motor, everything I have has a 5/8 or 3/4 hole and this shaft is 7/8.

 

[Alan in Little Washington]

Ah, you live and learn!

Sounds like you are good to go.

Depending on your VFD, you may be able to program a low speed so won't need to worry about running it slower than you want. Set the low end speed and the VFD drives the motor no slower.

It sure is nice being able to dial in the speed instead of messing with a pulleys, and even easier than adjusting a Reeves drive. Now, you either need to make a FREQ vs RPM chart or get a tach.

 

[Mike Davis]

Yeah, I got by with just a 400, 800 and and 1600 rpm pulley set for a couple years. Now it is time to enjoy turning.

My son is beginning to turn bowls and I worry about him turning a big chunk of wood at 400 rpm. I have had a few whompers on there and it gets hairy. The lathe is so big and solid the whole building starts to bounce and sway with the out of balance blank.

Hopefully now we can start slow and get the weight balanced at lower speeds.

Actually I bought all the wire and fixtures for something else that didn't materialize and had to look in the deepest corners of the shop to put it all together. But, it pays to have and not need, right? I don't even want to know what 50 feet of 10-3/Gnd cost now. But I'm sure 10-2/gnd would have cost a good bit less.