motor problems

[mistermajestic4@msn.com]

I have a 3 phase, 20 horse motor hooked up to 208 volts that according to nameplate should pull 50 amps at 230 volts, and table 430.250 is listed at 59.4 amps at 208 volts. The motor is fed with #4 in EMT, total length of wire is 115'. The motor is pulling 250 amps at start-up and drops to 68-71 amps under load. The motor is driving a compressor. In its previous location it was fed with #6 and 30' of total wire length and operated fine. The motor now takes too long to start up (starts slowly), the start up current is very high , and the running current is higher than listed. Any ideas what the problem might be? The current and voltage are balanced across the three phases.

 

[iwire]

Is the compressor seizing up?

 

[mistermajestic4@msn.com]

motor problems

No the compressor is running fine, and fills and cycles at the proper volume drop.

 

[Cow]

If the voltage is correct when the motor is under load, I would suspect the compressor has issues. Can you get a compressor tech out there to look it over with you?