Advise on selecting a compressor motor?

Compressor is an older Champion roll-around. Tank is about 10-15 gallons, compressor is a vee-twin, old U.S.-made I just put a new pressure switch on it, only to find the motor is bad. That motor was not original. I believe the original motor was 115V, HP unknown. What should I look for in a replacement motor? I prefer to stay with 115V.

I tried a 1 HP motor that was wired for 115V, and it was not enough - stalled and tripped the circuit breaker. How do I determine what HP it needs?

Reply to
RB
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Very simple.

Write down pump model number. Call Champion.

They have a database going back to at least 1930s. (did that with a pretty old compressor once) They have some nice ladies in the support department.

Reply to
Ignoramus31576

I considered that, but I can't find any sort of number on it. could be something stamped and covered with paint?

Reply to
RB

is there any flat part near the bottom of the pump?

Reply to
Ignoramus31576

There are several factors to consider, the first of which is the maximum rpm that the pump can run. The motor speed and the ratio of pulley sizes will determine that. With a lower rpm motor the pulley ratio will have to be changed so the motor is not overloaded. If you put a smaller pulley on the 1 hp unit it might have turned the pump but at a lower speed.

The ideal ratio is one that the motor is drawing the rated amps at the full pressure setting of the pressure switch. With a larger motor, there is more power to turn the pump faster and produce more air.

John

Reply to
john

Agreed. You can play with pulley sizes to get the best case from the existing motor.

You are trading off multiple factors:

1) How much air (CF/M) do you need? 2) How much money do you want to spend? 3) How long do you want to futz with it before getting annoyed?
Reply to
David Lesher
1 hp is about the max that you will want to run on 120 power, compressors are notorious for heavy current draw on startup. You might skimp to get 1.5 hp but that would be a push.

Check to see what the HP the replacement motor is (or is that the one you don't know about?).

The pump manufacturers rate the pumps at various HP depending on the output pressure and the rpm. Example: speedair has one twin cylinder pump with 1hp, 1.5hp, and 2 hp motors, the parts list shows the 3 different pulleys necessary to run each different motor.

You might want to look at the Granger catalog, try and match your pump to a current producti> Compressor is an older Champion roll-around.

Reply to
RoyJ

Is the unloader built into the pressure switch?

jw

Reply to
Jim Wilkins

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