Latest Discussions : Electrical & Lighting


05:21PM | 04/19/04
Member Since: 04/18/04
2 lifetime posts
I recently purchased a 240V Craftsman compressor for my garage and had a question about wiring. The wiring hook up on the compressor has three places to connect to. They are L1, L2 and ground. L1 and L2 are the two hots and the ground is self explanatory, but then what do I do with the neutral that comes from my power source? Do I connect it to ground or do I not connect it to anything and instead just put a wire nut on it? My feeling is that I just cap it, but I want to know for sure. There is one other device (clothes dryer) on this circuit.

Thanks for the help!

- Matt


05:41AM | 04/20/04
Member Since: 02/21/04
138 lifetime posts
The dryer should be on it's own circuit. If the dryer is on and pulling close to full load amps, when the air compressor starts up then you will trip the 30 amp. circuit breaker. I assume it is a 30 amp breaker.

To answer your question, yes the neutral wire would be capped.


09:06AM | 04/20/04
Member Since: 04/18/04
2 lifetime posts
Thanks for the advice. I figured it needed to be capped.

It is a 30 amp circuit that the dryer is on, with the compressor drawing 15 amps. I do realize that if the compressor and the dryer run at the same time, the breaker will pop. So, I'm just going to avoid that situation. Ultimately I'd like to run a dedicated line for both of them, but right now I'll just deal with only running one at a time.

- Matt


12:01AM | 05/30/07
Member Since: 02/17/05
2 lifetime posts
Hi Guy

I recently bought a Sears 2 stage 240v.

air compressor and have a problem.

Don't know where to put those (4) leads coming off the extension cord I bought to hook-up to the on/off switch box on the a/compressor?


1. White lead

1. Black lead

1. Green lead

1. Red lead

On the switch box there is:

L1 (what leads goes on that?)

L2 (what leads goes on that?)

Where do I put the ground wire?

Don't know what color the ground wire is anyway.

HELP !!!!





05:18AM | 05/30/07
Member Since: 04/25/05
1915 lifetime posts
What size is this motor? What is on the MOTOR LABEL for HP, Voltage, and current?

What is the size of this "extension cord"? How long is it?

What does it plug into?


02:56PM | 05/30/07
Member Since: 01/09/07
199 lifetime posts
This is a 240V appliance; it's highly unlikely that a standard extension cord would for this. Did you buy a normal extension cord, or was it a special 4-wire extension cord? What kind of plugs does it have at the ends. Proper extension cords that will work for 4-wire, 240 appliances are expensive, and rare (because in most cases, it is not legal under the code to run such appliances off extension cords -- they have to be hard wired).

But to answer your question about the connections:

white goes to the neutral wire from the breaker panel -- usually a white wire, or a black wire with a white stripe on it.

green goes to the ground wire -- usually a bare wire.

black and red go to the two 'hot' wires. Usually they are black and red, or maybe both black. It doesn't really matter which wire goes to which, but if one is marked red, connect that to the red.

If you are confronted with 3 unmarked wires, you can identify the neutral by the voltage -- there will be 120V between it and either of the other two wires, while there will be 240V between the 2 hot wires.


11:01PM | 09/19/17
I am wiring a 240v compressor with a 17 amp motor.
1) can I use 12-3 romex .
2) I will wire it to the fuse box with a 20 amp breaker.
3) I will run the "red" and "black" wire to the 20amp breaker
(the white wire and the bare wire go where in the fuse box ?)
4) I have a 20amp outlet but it has only 3 wire connection.

(planning on running a plug with a 4' 12-3 cable from compressor)

all help welcomed...thanks in advance.


06:37AM | 09/20/17
Member Since: 07/22/04
649 lifetime posts
"(the white wire and the bare wire go where in the fuse box ?)"They both connect to the neutral buss bar unless this is a sub panel.. The compressor only needs 2 conductor with ground connecting black and white(recoded black)to your double breaker and ground to ground.

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