I have a 30amp wall socket in my garage, connected to two 20amp fuses in my garage sub box. I bought a 60 gallon air compressor rated 230v 15amp (non-reversible???). I am under the impression that I can use this compressor with the socket I have. The compressor did not come with a plug but did have the wires. One red, one green, one white. The plug I bought to the match the socket has instructions for one black wire (hot) one green (ground) and one white (neutral) I guess my question is, would the red wire be my hot wire? Does everything else sound ok?
Sounds like you may have a mix of 115v and 230v parts in your circuit.
The bottom line is that your load is 15a at 230v and your supply is 20a at 230v so it should work. 230v has two hots, usually black and red.
The only thing that sounds strange is the red/white/green combination on the existing compressor wiring. Some tools, like compressors, table saws, radial arm saws etc. can be wired for either 115v or 230v. You may want to check that your compressor is not already wired for 115v. IF it's already set up for 230, then once you match up comparable plugs to outlet it should work.
Good point about the compressor being set up for 115v. When I originally looked at it, the thought crossed my mind but the sticker/plate on the motor didn't say anything about 115v so it slipped my mind. See picture.
So would a 230v set up have two live wires, a ground and a neutral wire? If so, I seem to be missing a wire both coming from my compressor and in the diagram for wiring the new plug.This message has been edited. Last edited by: HillBillyBuddha,
Here is a NEMA plug and receptacle chart:
Can you take a look at that wall outlet you have and tell us what NEMA number that receptacle is. If it's a 220 volt 30 amp receptacle, I'm expecting it's a NEMA 14-30.
Is that correct?This message has been edited. Last edited by: Nestor,
It's a nema 6-30 wall socket. I got the matching nema 6-30 plug. I decided to just go for it. Just finished putting it together and it works so I'm not complaining.
So, did you:
1. Connect the red wire from the motor to the connection point for the black wire on the plug,
2. Connect the white neutral wires together, and
3. Connect the green ground wires together
and having done that, you pluged it in to your 6-30 socket and the compressor started and ran fine without the motor overheating?
Is that correct?
Yeah, seems to work perfectly. After pulling the access plated off of the starter and engine, and realizing that not only is there no fourth wire, there is also no place to put a fourth wire. I just went with it. Works great. No over heating at all.
If that's the case, then I don't understand that wiring what-so-ever.
You see, house wiring consists of two hot wires (red and black), each of which carries 120 volts AC. But, the voltage sine wave in those red and black wires is out of phase by 180 degrees, so that when the red wire is at +120 volts, the black wire would be at -120 volts, and vice versa. So, if you measured the voltage between them, you'd have 240 volts AC, and that's why 240 VAC appliances like clothes dryers and electric ranges must have both the red and black wires going to them.
In your case, you have a neutral wire, a ground wire and only one "hot" wire. I am at a total loss to figure out how you can get 208 volts AC into a single wire (presumably) coming from your house. You SHOULD only have 120 volts available to you if you're only using one "hot" wire to run your compressor motor.
I'm going to put this one in the same bag as the Bermuda Triangle, crop circles and UFO's.
I'm with you on this one.
"Why isn't everyday Earth Day ?"
I'm calling imported compressor here. whatever they get cheapest generally goes in.
green (or brown on the British side of the pond) is almost universally ground. that is easy to check with a meter or a test lamp. stuff gets blocked at customs if that isn't right.
for 240V service, that leaves two wires for single-phase 240 volts.
as always, YMMV. I'd recode that white wire with 33+ black tape, just because I'm a crank, and I don't leave things iffy.
sig: if this is a new economy, how come they still want my old-fashioned money?
Actually its an older compressor. All the different parts are printed or stamped, "Made in America" and in smaller letters. Meaning to me, that it was made in a time that "Made in America" was assumed and not something that was unusual and needed attention drawn too. My only assumption about the weird wire colors is a previous owner. I have no assumptions about the lack of a neutral (or is it the lack of a second hot) Regardless, I use this compressor almost everyday and it works better then my old Husky Brand 60gl 240v 5hp 15amp set-up. Much better actually. With much less efforts.
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