breaker size

by Rob
(Ontario, Canada)

I just bought a new MaxAir 80 gallon 18.5 CFM compressor. It is rated at 21 Amps, 240 Volts. What size breaker do I need for it? I am not sure if a 15A 240V breaker will supply 15A to each line or just a load that adds up to 15 Amps. Does the 21 Amp rating mean that it pulls 10 1/2 amps off each of the 2 lines?

Comments for breaker size

Click here to add your own comments

May 14, 2012
Breaker sizing
by: Buster

Hey Rob, the current reference is for each leg of power coming to the motor. For safe and reliable operation, you will need a 30 amp double pole circuit breaker and use 10 gauge wire to feed the motor. When a motor starts, there is a very high inrush current momentary to get the motor started and then drops to rated current when the motor gets up to speed. The 30 amp breaker should serve your purpose well.
Hope this helps.
Buster

Click here to add your own comments

Add your own question or comment. It's easy to do. How? Simply click here to return to Electrical-troubleshooting-compressors.

how to connect the circuit reset button up?

by Jeff
(Haysville,Ks USA)

I have a dual voltage Puma compressor and changed it from 115V to 220V how does the circuit reset connect?

_____________________

Bill says...

Jeff, this I've never done. I hope someone out there can give you some guidance.

If not, talk to your local electric motor rebuild shop to see if they can help.

Cheers,

Bill

Click here to post comments

Add your own question or comment. It's easy to do. How? Simply click here to return to Electrical-troubleshooting-compressors.