Thanks again for all the replies. One of the links that Jraef posted (http://www.ssusa.cc/reference/wiring_diagrams/standard_series_drawings/series_107/107_21.pdf) is exactly the circuit used in the compressor we have. If you look at the schematic, you'll see that there is no overload...
Thanks to all for their replies. If I understand correctly, I need to add 2 overload relays to monitor the current in each of the delta windings. The FLA of the motor is 63 amps, so I want each OL relay to be set at approximately 37 amps. I would wire the N.C overload contacts in series with...
We just had a 50HP compressor motor burn up. It has a star / delta starter. One of the delta contacts failed, causing that part of the winding to single phase. The overload relay never tripped. Motor FLA is 60 Amps. Overloads rated at 63 Amps. Overload relay is connected to T1, T2, and T3...
