Jason wrote at 2014-12-04 04:50:05
I understand this is an older question. However I have ample experience with various compressors from tiny hot dog units to large industrial units at different voltages from 120v to 440 3 phase and I would like to add my input for future readers. Consumer compressor horsepower is "fake" therefore you cannot use NEMA amp draws. They take the max amp draw, and convert that to a horsepower rating. The 3 HP Craftsman compressor in the original question is probably a true NEMA 1/2 - 3/4 HP motor (Unless it is very old, pre 70's). You must take the amp draw off the motor, not the HP rating, to figure amps and wire gauge. As far as running compressors in the home, I have two compressors, a 5HP and a 3HP. These are both industrial units running at 220 volts, the 5HP draws 21 amps, the 3HP I forget. It's a very (very) old motor, so probably not much less. And yes, they run off of circuit breakers, and if I need to start or stop them, it is done with the breakers. To think that a circuit breaker is that fragile is ridiculous. As a note, on any compressor or appliance drawing substantial amperage (let's say over 10 amps) on 120v I would highly recommend running it at 230v which cuts the amp draw in half. The wire gauge can be lighter, you will have less over all draw on your power system, and the compressor will start easier.
Three phase/ AC DC single phase motors, controls, any problems or failures, motor installation, performance issues, connections. All other electric motors/gearboxes/apparatus. Specialty repair concerns, obsolete motors and solutions. Other mechanical or specialty equipment.
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30 plus years in the electrical motor and apparatus repair industry. VP level management of repair facilities, current owner of my own specialty repair and consulting firm.
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