3 HP on a 15 Amp 120 v circuit

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This Makita Air compressor is labeled 3 HP but has a 120 V 3 prong cord. I'm used to the limit being 2.4 HP on a 15 Amp breaker. (120 V x 15 A)/746 Watts per HP. Does anyone know the answer on how Makita expects this to be run on a 120 V outlet.I suppose one option is to upgrade to a 20 A breaker if the wiring is up to it. A search of the internet brought up a fellow asking the same question about the same compressor.

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peak hp its how shop vacs are 6.5hp.

that air compressor draws around 13.8amps. so its really more like 2 continuous hp.



ps those are great air compressors.. none better in that size.
 
Snag it's the new math. Smoke and mirrors

746 Watts per hp and don't forget to add the service factor. Modern motors are usually 1.15 sfa the good old ones were 1.25 sfa.
 
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There was a bit in the news years ago about air compressors having misleading or meaningless HP ratings, namely against Craftsman and CH. Their cryptic rating was based on the instantaneous power it could deliver for a split second from the inertia of the rotating assembly if it suddenly stopped. Totally meaningless for an air compressor, but I'm sure the marketers thought it was a great idea. I have a "3 HP" Craftsman that was rated at 13 amps at 120 volts. Yeah, sure. Thought it was funny when years after I bought it, it was recalled for a possible fire hazard, and when it came back from repair it had a new sticker on the motor shroud that says 1.5 HP. Guess they decided they had to come clean and state that it's not really a 3 horsepower motor.
 
Their horses aren't Clydesdales, more like Shetland ponies! You should be OK, but a stout extension cord & running on a circuit with nothing else will be necessary for 15A 120V.
 
Originally Posted by P10crew
Snag it's the new math. Smoke and mirrors
746 Watts per hp and don't forget to add the service factor. ...
... And that's per horsepower electrical input power. Mechanical output power will be substantially less, because the motor is not 100% efficient.
 
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