Air Compressor

Thanks

You also need to check the rpms on the two motors and make allowances for any required adjustment to the speed reduction.

In theory, if you have a replacement motor that has half the horsepower but the same rpm as the original, you can interchange it by using a smaller pulley on the motor. However, those pulleys are usually pretty small to begin with, and it probably isn't practical to install a larger pulley on the compressor.

My recommendation is to repair the original motor, or replace it with an equivalent one.

One last thought: Air compressor manufacturers are notorious for exaggerated horsepower ratings. A 3 hp motor at full rated load is going to need around 27 amps on 120 volts, or 13 amps on 240V. If this is a 120 volt compressor, I can guarantee you that it is not a true 3 horsepower compressor. Probably more like a horse and a half.

Also you didn't detail your motor problem too much. Does it run at all? Does it smoke? Could be a simple matter to fix.

Pooh Bear

You can use a smaller horsepower motor, but as noted you also have to use a smaller pulley to give it a little more mechanical advantage in turning over the compressor. It'll take a little longer to fill the tank because the smaller motor can't turn the compressor as fast.

Check the motor speed and direction of rotation...the compressor motors I've tinkered with turn in the opposite direction of the typical small electric motor. Some motors you can change direction, some you can't, should be instructions on the motor tag if you can. Suspect the compressor itself would work in either direction, but the cooling fan incorporated into the compressor pulley would blow in the wrong direction.

Keith