Re: Need Electrical Help

Sat Apr 02, 2011 11:48 pm

Now I feel a little stupid! After looking on the internet for a wiring diagram for days I took the cover off the pressure switch. Guess what I found? Stuck to the inside of the cover was...... the wiring diagram! DUH!!! Low and behold it shows WHITE,BLACK and GREEN. Couldn't have been more obvious!
Anyway,I love my new compressor! So far I have used an air grinder,air ratchet and HVLP spray gun and all have worked great. All that without that steady growl of my smaller compressor.
So in conclusion thanks to everyone that offered advice on this subject!

Re: Need Electrical Help

Mon Apr 04, 2011 12:54 pm

Your compressor switch label is for a 3 wire plug. You stated you have 4 wires. For a 3 wire plug, the hot legs, L1 and L2, are black and another color, in this case, white. You have a 4 wire cord and the color convention is L1, L2 are black and another non-white non-green color, in your case black and red. In a 4 wire 220 volt cord, the white is reserved for the neutral 110 volt leg.

If you have a 3 wire plug installed then use the white or red, your choice as long as the switch and plug are the same. If you have a 4 wire plug then it is not according to convention and should be changed at both the switch and plug so they match convention.

I have not seen a photo of your cord but it seems like someone took a 3 wire plug and used 4 wire cord. Sounds like it is working so electrically it must be correct. I have my fathers old ( 50 year old) 1 HP compressor. I get to sandblast for 15 seconds then wait minutes to reload.