ok. I have power to a switched box that i will wire to my compressor. i have 4-strand 6 gauge cord. problem is compressor has 2 hot and a ground, no neutral. what do i do with my white wire? my googling came up with: A. attach it to the breaker along with the black. (sounds sketchy, why not just not use it)? B. ground it at the compressor. Sounds better but ? Any help would be great.
Absolutely not. ...
... No, again....NEC says grounds _MUST_ be green/bare. Besides, what's the point, there's already a ground.
For a 220V-only load, you only need 2 hots and ground. If you want to use this cord, cut the unused white supposed-to-be-neutral flush to the trimmed outer insulation at both ends and fuggidabowtit was ever extant.
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Don't use it. It isn't needed for a 240V circuit.
Wrong.
Indeed.
Also wrong.
Don't connect it to anything at either end. Put a wire nut on each end so that there's no possibility that the conductor might come in contact with anything live.
As others have stated, neither A nor B is correct, there is no neutral connection. The *best* solution would be to use _3-wire_ cable (2 hots plus ground).
thank you all. the simplest solution is usually the correct one!
I would connect it (the white wire) to the neutral bus at the breaker panel, and put a wirenut/tape on the wire at the switch end, in case you want to use the neutral later (for a dryer, etc.)
Bob
I always thought the white wire was the neutral and should be connected to the neutral buss. The ground wire (green or bare) can go to any metal on the object that is being wired or to a ground rod or the neutral buss too.
Am I wrong here? If so, how?
Hank
Hank you're correct - except the "ground to ANY metal."
I guess a better definition would be:
Load bearing neutral - [such as might be used for 110v] as opposed to a safety ground - [used for safety in both 220v or 110v applications]
So, two hot(s) L1 / L2 for 220v and one green [safety]. The white neutral is load bearing if you want to split the 220v to 110v - L1 to N or L2 to N...... if you're not intending on using 110v then cap the white lead off [as suggested.]
All metal raceways within the buss should be grounded / bonded.
Is that helpful?
Yes, you are.
1) White wire is neutral and *must* (not "should") be connected to the neutral buss _in a 120V circuit_. The OP is talking about a 240V circuit. In North America, 240V circuits have two hots but do not have a neutral. When a 240V circuit is wired with 2-conductor cable (plus ground) the white wire is marked black or red at each end and connected to one pole of a double-pole breaker, while the black wire is connected to the other pole. When a 240V circuit is wired using 3-conductor cable (plus ground), the white wire is not connected.2) The ground wire must be connected to the chassis or case of the object being wired, not "any metal".
3) In a main panel, the ground wire is permitted to be connected to the neutral buss, since the neutral and ground busses are required to be bonded together. In a subpanel, the neutral and ground busses are required to be electrically isolated, and the ground wire *must* be connected to the ground buss, never to the neutral buss.
It is called a Condensing Unit (or, A/C unit) ; it is not 'a Compressor' . The Compressor is inside the Unit and it pumps the freon in a gaseous state. You are wanting to wire the Condensing Unit/ A-C Unit. When you are discussing wiring, it is imperative to use the correct labeling of what you are wanting to wire. Thank you.
Dave: WTF
It is actually an Ingersoll Rand 7.5-HP 80-Gallon Two-Stage Air Compressor (230V 1-Phase). But, I agree, best to be clear.
And one more time, thanks to all.
Having written that, the OP will probably post again. And, it will be a shop compressor with a 50 gal upright tank, for running air tools.
Sounds like the one writer had it correct. Wirenut the one end of the white, tie the other end to the neutral. Hook up the black, red, ground.
Please remember to check the oil level in the crank case. Many compressors use ND-30, which is available at Napa.
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