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jstenvme1980 · Jul 16, 2007, 05:59 PM

I have a Champion compressor I came across dirt cheap but it is 3 phase I bought a new 1 phase motor for it wired up a 220 plug and Now I need help wiring the compressor for that switch from 3 phase to 1 phase any ideas?? I am worried about smoking my new $400 motor

Thanks in Advance
Nick (The Mechanic Not electrician)

acetc · Jul 16, 2007, 08:49 PM

When you disconnect the wiring from the old motor you will see three wires (line voltage) and maybe a ground wire (usually green) remove one line wire or tape it off . The new motor may pull more amps then the old motor (compare FLA rating on both motors ) You may have to increase the wire size. Connect the two wires and ground wire to new motor following the wiring diagram on the new motor, check rotation and reverse if necessary, there is normally an arrow on the compressor pulley wheel.

labman · Jul 16, 2007, 09:04 PM

Are you talking about power to the motor, or the controls? When it reaches the set pressure does it unload the valves or shut the motor down? If it had a 3 pole relay, you can just connect 2 of the 3 poles on both the line and load side. Just make sure one of them is the pole the line to the pressure switch comes off.

tkrussell · Jul 17, 2007, 02:42 AM

If the compressor unit came with a magnetic motor starter, (relay), each of the 3 poles on the starter have an overload heater in line , usually at the bottom, or the load of the starter. These will need to be replaced with OLH that will match the running load amps, RLA or FAL, of the new motor. The rating of overload heaters should be 125% of the RLA.