Advice for converting Sears Craftsman 220V compressor plug to washing machine plug

[clare]

Evan - sorry but your ignorance is showing. Virtually every item you plug into a 15 or 20 amp 115 volt receptacle in your home is rated MUCH below the 15 or 20 amps the receptacle is rated at, and the breaker is designed for. It is NOT a safety issue. Your computer draws something like 2 amps, the monitor 1/2 amp, a 100 watt light bult less than an amp, your fancy little transistor table radio about 250 milliamps.

The "right" way to do it would be a "fused adapter" with a 30 amp plug that fits the dryier receptacle, and a 20 amp receptacle to fit the compressor plug, with a 20 amp fuse or breaker between the two. This would protect the wiring to the compressor motor - which, in all likelihood, already has a thermal shutdown protection device built into it - making the fused adapter redundant anyways.

[clare]

If it is a 20 amp 220 plug on the compressor, it would need 40 amps at 110, which is very non-standard. Assuming the 20 amp plug is already over-sized a bit, he might get away with a 30 amp 110 volt circuit - which again is definitely "non-standard" in today's residentiial wiring scheme.

[clare]

Actually, the dryer may have an issue with today's code as it is using the "ground" as a neutral for the 110 volt lamp, motor, and timer circuits. Today's code (at least here in Ontario Canada) requires a FOUR wire plug for dryers and other 220 volt devices that use 110 volts as well.

The compressor is a straight 220 device - not requiring a neutral (which is being "faked" on the ground on a 3 wire plug)

[Jon Danniken]

FatterDumber& Happier Moe"

[clare]

Zip tie the 20 amp "receptacle" to the compressor cord and it is no longer a receptacle but part of the compressor, and that portion of the code is no longer applicable.

[clare]

You are right and safe. Use it.

[Gordon Shumway]

The only thing I can say is what has already been said. If you have to ask these questions you should not be doing this job. This is something left for the professionals.

Consider what could happen to your family if you assume wrong...

[RBM]

The compressor won't work, and they'll run out of air?

[clare]

HOLD ON - I think Steve caught something I missed - you did say ONE blare is crosswise, not 2 - right? That COULD BE a NEMA 5-20 plug. oR IT COULD BE A 6-20. BOTH crosswise would be a 6-15.

WHEN YOU HOLD THE PLUG WITH THE PINS FACING YOU AND THE "U" GROUND DOWN, WHICH SIDE HAS THE "ROTATED" BLADE?? Rotated blade on the right os a 5-20 - 115 volt 20 amp. (nominal) Rotated blade on the left is a 6-20 - 230 volt 20 amp (nominal).

If it is a Nema 6-20, go ahead you are OK (and I think you DID say it was a 6-20R that you were using - which would not let a 5-20P fit)

[clare]

Doesn't really matter if you are on a sub-panel or not as you are not using the "neutral" - it is simply a "safety ground" - and YES, you did pick the right neutral (actually, ground)

[clare]

If his copressor plug fits the 6-30R he bought, I strongly suspect your suspicion is wrong.

[Gordon Shumway]

That's one possibility I hadn't thought of. Another possibility is the compressor will suck. That's the logical possibility. After all, it is a Craftsman compressor...

[dpb]

jamesgangnc wrote: ...

no, No, NO, _NO_!!!

One more time...the third wire in a 3-wire dryer circuit _IS_THE_GROUND_ wire allowed by previous NEC to double as the 120V neutral. It is not, repeat _NOT_ connected to the neutral bus.

--

[RBM]

When you're dealing with amateurs, there are many ifs. With the similarities between nema 20 amp 120 and 240 devices, it's difficult to determine what he bought, or thought he bought, however as the string progressed, it became clear that he does indeed have a 240 volt machine. Had you followed the progression, you may have noticed this as well.

[RBM]

Yea, but it's on old Craftsman, from when the sucked less

[RBM]

It has to original at the service panel, where the neutral/ground conductor of the dryer cable connects to the neutral/ground buss of the panel. It cannot originate in a sub panel where you have separate neutral and ground busses

[RBM]

My mistake, it has to originate in the service panel if type SE cable is used. If a cable with an insulated neutral is used, it can originate in a sub panel, in which case the neutral/ground conductor would go to the neutral buss

[clare]

"the sky is falling, The SKY is FALLING" - Chicken Little.

[Steve B]

You'll shoot yer eye out, kid?

Three wires is pretty hard to screw up. The only thing is that the dryer/range plug will have too big a breaker, and if the compressor overheats, it won't pop off in time to save it.

Steve

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[Stormin Mormon]

I wouldn't want to plug a two phase compressor into a single phase socket.