Electric Motor Rated Vs. Start-Up Current?
Electric Motor Rated Vs. Start-Up Current?
(OP)
I'm trying to pair a portable generator to a 3-5hp air compressor. The compressors I'm looking at all all rated 19-22 amps and the generator will mainly be powering the compressor, so it only needs to have enough power for this purpose. I understand electric motors require a significant current draw to start up, but of course this isn't listed in the specs. Should I just assume I need a generator with enough surge wattage to supply twice the rated amperage of the compressor I intend to power, or is there a way I can more accurately calculate my requirement?





RE: Electric Motor Rated Vs. Start-Up Current?
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RE: Electric Motor Rated Vs. Start-Up Current?
RE: Electric Motor Rated Vs. Start-Up Current?
If the compressor manufacturer can provide the motor NEMA starting code, you can estimate the maximum locked rotor amps and provide this info to the generator supplier.
Engine-generator suppliers deal with this issue daily and will be willing to help you.
RE: Electric Motor Rated Vs. Start-Up Current?
Three phase motors generally have a NEMA code on the nameplate that allows the initiated to look up the ratio of starting current to rated running current in the appropriate references. Not usual for single phase motors.
Bill
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"Why not the best?"
Jimmy Carter
RE: Electric Motor Rated Vs. Start-Up Current?
Keith Cress
kcress - http://www.flaminsystems.com
RE: Electric Motor Rated Vs. Start-Up Current?
StrykerTECH Engineering Staff
http://www.stryker-tech.com/
RE: Electric Motor Rated Vs. Start-Up Current?
I was hoping to avoid using a gas powered compressor because of several factors, mainly the problem of situating the gas engine and compressor pump on my step van, but it would appear this will be what I must do. I'm just going to have to build an under-body rack on which to mount the engine and compressor and plumb it to a remote tank. Of course, this will save me a small fortune on a generator, so it's not so bad.