Voltage Drop

[rp9ball]

I have a ice cream compressor motor that keeps tripping internally (not the breaker). The technician says its due to voltage drop. The run is about 250', #10 wires, 20 amp circuit, single phase. Our meter reads 116 volts. When the compressor motor starts the voltage drops as low as 98 volts. FLA = 15. We moved this machine to a receptacle next to the panel and it worked just fine. The service is 120/208. Any suggestions or ideas (besides larger wires; the conduits are full and the data guys used our spare)
Thanks in advance.

 

[hurk27]

Re: Voltage Drop

I have to say that the repair man is correct as the startup current can be much higher than the FLA current and it can be as high as the LRA amps. if you throw this current you will see the motor is starving. See if the repair man could install a powerfactor correction capactor. or a booster starting capactor? It will be allot cheeper if it works. Is the machine only 120 volts or does it use 240 volts also? Another way to get more power to it is with a 2 or 3 kva step down transformer. (not a buck/boost) reconnect the branch circuit to 208 volts and step down at the load end back to the 120 volts, This would bring it back in line.

[ March 02, 2005, 02:15 AM: Message edited by: hurk27 ]