Can I run a compressor pump with a smaller rated motor?

Can I run a 10 HP compressor pump with a 7.5 HP motor by for instance, using a smaller motor pulley? This would run the pump at a lower speed which would mean less CFM and possibly lower maximum PSI. Would running the pump slower than spec have any negative effect on the pump or would the effect simply be less CFM and possibly lower PSI?

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Bill says...

While running the compressor pump with a smaller motor won't harm it, the compressor may not run at all.

The compressor is mechanically designed to run with the force rotating the shaft that a 10 HP motor and the sheave impart.

Changing sheave sizes may overcome the mechanical disadvantage of a smaller motor, and what will suffer then won't be pressure, but rather, capacity.

I don't think you can hurt the pump by changing motor size, like I say, it may just not work right.

Cheers,

Bill