NEMA 10-30 for ground?

[jeremy_ho]

I have a 240V Air compressor I want to wire up. (2 hot and 1 ground)

As the motor plate listed 23 AMPs, the breaker will be 30 AMP dual pole, wire is 10/2 NM with ground. Running conduit to a 240V receptacle, from here a stranded cord to the motor junction box of the compressor, to handle vibration better than solid copper wire such as NM. (as least I think..)

What I planned is to find a dryer cord as it already has the plug, stranded and the lugs crimped on, it would be perfect. I wanted to use NEMA 6-30 plug, as it has ground and 2 hots which matches my wiring. I can find the receptacle, but I cannot find a NEMA 6-30 dryer cord, probably because they are not allowed anymore?

So, can I use 10-30P and wire the "W" prone which is normally neutral with a ground? I am thinking it is not to code, but wanted to know the alternatives here..

The cheapest solution might be wiring a 14-30R properly and just disregard the neutral? ..Since all parts are readily available. But I didn't really want to use the 10/3 wire as this is a dedicated circuit for the compressor..

Thanks.

[Steve Barker]

the 3 prong dryer cords are still available.

[Steve Barker]

[jeremy_ho]

I can easily find 3 prong cords but their configuration is always NEMA

10-30 and not NEMA 6-30 like I am look>

[gfretwell]

Yup and they are about half the price of the 4 prong. I have my compressor, my big pressure washer and buzz box welder all on dryer plugs so they are more portable. With my 50' #6 SO extension cord I can use them at almost anyone's house.

[gfretwell]

Try Dale-electric.com

[zxcvbob]

Since it's a dedicated circuit, you should be able to use it.

You might want to look for a 30A Twistlock plug and receptacle. It'll fit in a normal outlet box.

Bob

[Dan Lanciani]

In article , jeremy [e-mail] writes: | I have a 240V Air compressor I want to wire up. (2 hot and 1 ground) | | As the motor plate listed 23 AMPs, the breaker will be 30 AMP dual | pole, wire is 10/2 NM with ground. Running conduit to a 240V | receptacle, from here a stranded cord to the motor junction box of the | compressor, to handle vibration better than solid copper wire such as | NM. (as least I think..) | | What I planned is to find a dryer cord as it already has the plug, | stranded and the lugs crimped on, it would be perfect. I wanted to | use NEMA 6-30 plug, as it has ground and 2 hots which matches my | wiring. I can find the receptacle, but I cannot find a NEMA 6-30 | dryer cord, probably because they are not allowed anymore?

I don't think 6-30 was ever used for dryers, at least not residential ones. If you are trying to find a "dryer cord" that might be your problem. Look for heavy-duty air conditioner cords or perhaps arc welder cords.

Dan Lanciani ddl@danlan.*com

[Steve Barker]

I see what you're saying now.

I had to look at pictures.

[Toller]

You can do whatever you want on the plug; but the outlet must meet code. You cannot wire them wrong because someone else (or who knows, maybe even you) might plug something in expecting them to be wired correctly.

Consider using 10/3. The cost isn't that much more and it means only doing the job once if you ever come up with a use that requires a neutral. I installed a generator hookup with 10/3 eventhough my generator only needed

12/2 because somebody might want to use a bigger generator some day.

That said, all my 240v is wired with "uninsulated neutral"s. Beats me how they are different from grounds. They don't meet code now, but did when installed.

[Doug Miller]

Here's how they're different from grounds: they carry current under normal operation, at least to the extent that there is an imbalance between the two legs of your 240V circuit (e.g. 120V timers, motors, etc).

Grounds carry current *only* in the event of a ground fault.

[gfretwell]

"Dryer plugs" traditionally were using the neutral as the ground, not the other way around, so that 3d wire was usually insulated white. Since 1996 that practice is not legal in new wiring so the 3d connection is only a ground. You could always wire it with a bare wire (SE cable) if this was coming from the main and not a sub panel.

[mm]

Don't you mean that grounds carry current in the event of a neutral fault?

Ground faults trip ground fault interrupt? circuit breakers, but this is precautionary iiuc. So you'll have to fix your ground to be ready in case you ever need it.

[Toller]

That is what I expected, an insulated white, but there is only a bare wire. It says right on the cable "uninsulated neutral". House was built in 83.

[Doug Miller]

No. "Ground fault" means a fault to ground, i.e. current leaking or shorting to the grounding conductor.

[Thomas Horne]

Jeremy Why is it you won't go to an electrical supply house and buy a NEMA

6-30 receptacle and plug end plus the needed length of 10/3 SO cord. The devices I'm talking about are shown here

-- Tom Horne

[zxcvbob]

Woo-wee! I looked at L6-30 plugs and receptacles today at HD. I was amazed at how expensive they are. (especially the plugs)

Do you need a plug, or can you hardwire it? Use 8-2 NM or SE cable from the compressor to the junction box and it'll have fine stranded wire. Nice and flexible. That's the only size that uses fine stranded conductors.

You could also use #12 or #10 SJO flexible cord, with a cable clamp where it comes out of the J-box, but I don't think you're supposed to permmanently attach flexible cord.

Bob