230v motor wiring

I was struggling thinking of where to go for help with this without going to an electrician, might as well try here first.

Ive got a 2 hp air compressor motor that im wiring up for a belt sander but I cant for the life of me get it to work. Initially to test the motor I wired up the black and white leads coming off the motor to the two hot lines and the ground to the green wire, plugged it straight into the wall and it fired up and spun. I cant quite figure out how it worked in the first place seeing as the green wire isnt actually acting as a line but as the ground. All the pictures are the sections ive got to try and get this to work, keep in mind i will be changing out the wire thats going from the motor to the switch since the 12 gauge wire isnt enough to sustain a load. Both prongs on the outlet are reading 120 volts, and the ground lug has no volts. Every time i flip the breaker on with the switch set to off the breaker either blows or its fine until i switch to the on position, where it blows the main breaker to the entire shop. Any ideas?
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Why is your red hooked to ground?

I wired up the line to have red as the return wire, which is using the ground lug. Not sure why since white normally return but this is just a testing setup to make sure it works before i do it all proper.

On your plug, you have red as the ground, white as hot and black as hot. On the light switch, you have both hots (black and white) to one terminal and the ground to the other terminal (red). When you flip the switch on, the circuit gets grounded and you will draw max amperage until your breaker trips or a fire starts/wire melts/etc.

I would recommend an electrician to help you out. An online post can be cold, but I'm trying to be nice --> you have mixed up the wire colors, you are using a solid copper wire for a cord and you did not recognize the ground wire inside your 4 wire cord that you are using as the cord from the plug to the switch. On further inspection, it appears that the wiring for the switch has more mistakes in it. I would recommend an electrician. I'm not trying to be harsh and please forgive me if I sound that way.

Suggest trying an electrician over at homeshopmachinist.com

In addition to the other comments, I have to wonder about the switch in the photos. I suspect it is what is called a "four way" switch which is intended to be used in a light circuit where three or more switches are used to control one light. These are usually 115V circuits, nor 230V ones. A switch for controlling 230V would either switch only one leg of the two hot legs (not a good idea and probably not up to code) OR it would be a TWO POLE switch which would have two terminals marked "Line" (perhaps Line1 and Line2) and two terminals marked "Load" (perhaps Load1 and Load2). I can not tell from the photos, but your switch does not appear to be that type.

I suspect that you really do not understand electrical wiring and your attempts worry me. I also strongly suggest that you do consult an electrician before your burn the house/shop down or injure yourself.

Not clear if this is single or three phase. I have a older tablesaw that was factory wired with black, white,green for three phase. they used the green wire as one of the three phase power legs. There was no separate ground wire to the motor. They figured the metal frame would act as ground lead from the switch box. This was made around 1960 or earlier. It did use four conducter wire with ground into the switch box
Bil lD

Bill D said:

Not clear if this is single or three phase.

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I'm pretty sure it's single phase Bill. The green wire is bolted to the frame of the motor to indicate it is a ground and there are two other leads. Also, the nameplate on the motor indicates single phase.

medsar said:

On your plug, you have red as the ground, white as hot and black as hot. On the light switch, you have both hots (black and white) to one terminal and the ground to the other terminal (red). When you flip the switch on, the circuit gets grounded and you will draw max amperage until your breaker trips or a fire starts/wire melts/etc.

I would recommend an electrician to help you out. An online post can be cold, but I'm trying to be nice --> you have mixed up the wire colors, you are using a solid copper wire for a cord and you did not recognize the ground wire inside your 4 wire cord that you are using as the cord from the plug to the switch. On further inspection, it appears that the wiring for the switch has more mistakes in it. I would recommend an electrician. I'm not trying to be harsh and please forgive me if I sound that way.

Click to expand...

No worries, im just trying to avoid an electrician since they charge almost $100 an hour in this area.

I do not understand that switch. I would buy a two pole switch designed for 240 volts single phase. It will connect and disconnect two seperate switches at the same time. DPST.
Wiring into the motor is not exactly correct the white should be marked hot at both ends with black tape, heatshrink, paint etc. The green shall never be switched.
Color code is easy green or bare is ground, white is neutral(not used here) Any other color is hot(often red, black or blue).
Bill D

That is the wrong switch. DO NOT USE IT.

Also because it has carried large fault currents it
should be discarded.