Running vs peak hp question

[jonlb]

I recently got a free Campbell housfeld 60 gallon air compressor. The sticker on the front says 7.5 hp but does not specify running or peak. My question is how much running hp could it possible have with a 21 amp motor? 7.5 seems A bit ambitious.

 

[rockchucker]

There should be a Sticker on the Motor Case telling you what the LR (Locked Rotor) or Starting Amps are and the RA (Running Amps).


Here...


http://sawdustmaking.com/ELECTRIC MOTORS/electricmotors.html


The 7.5 Horsepower seems a touch off even if it is running at 220v it should only be about 4~5 True HP. If it is on a 110 Circuit then it should only be about 2.

 

[A_Pmech]

"Peak horsepower" is a scam, I think they base "peak horsepower" on starting current, which is much higher than running current.

A 21A single phase 230V motor would produce about 3.75 HP.