Eric MFG

07-01-2012, 10:08 PM

Hi Guys,

I’m having some problems with a 480V three phase rotary air compressor, the compressor keeps blowing a single time delayed fuse. I was performing a quick and dirty ohm test on the motor not sure what the coil windings resistance should be. Basically I tested each leg to earth ground my readings were, L1 and L2 were 1.5 ohms and L3 was 65 ohms. Does anyone know where I could find motor technical specifications?

I know the resistance will be relative to horse power ratting voltage exedra.

Also if a motor is rated 40 amps 480 volts does that mean 40 amps is the total draw of all three legs combined? So would the 40 amps be divided in to each leg? Knowing voltage and current draw per leg I could figure out the resistance with ohms law or somthing close.

Thanks Eric,

I’m having some problems with a 480V three phase rotary air compressor, the compressor keeps blowing a single time delayed fuse. I was performing a quick and dirty ohm test on the motor not sure what the coil windings resistance should be. Basically I tested each leg to earth ground my readings were, L1 and L2 were 1.5 ohms and L3 was 65 ohms. Does anyone know where I could find motor technical specifications?

I know the resistance will be relative to horse power ratting voltage exedra.

Also if a motor is rated 40 amps 480 volts does that mean 40 amps is the total draw of all three legs combined? So would the 40 amps be divided in to each leg? Knowing voltage and current draw per leg I could figure out the resistance with ohms law or somthing close.

Thanks Eric,