We have a 4160 V system that is low resistance grounded. The transformer supplying the 4.16 kV system is a 10 MVA, 13.8 kV Delta-Wye with a 12 Ohm neutral ground resistor. There is a temporary feeder being installed to supply some 480 V equipment along with a 4160-480 V transformer, however...
We haven't been able to investigate this further so nothing to report yet. I'll update this thread once we determine the cause or have more information. I do appreciate everyone's inputs.
Gr8blu - I believe you are correct. The doesn't seem like the motor ever synchronizes. It is a brushless motor and the field is applied as soon as the motor starts. The following information is what we have for the start. The initial current is ~1600 A (motor FLA is 428 A), the current drops...
panter - no, we don't have access to the motor to measure the resistance of the rotor windings at this point.
wcaseyharman
Motor voltage dipped to 3815 V during the start, but was back to 4120 V within 3 seconds. I don't have the field current readings during the initial start, but right...
We have a sync motor that is tripping on power factor shortly after it starts. The motor comes up to speed and the trips on power factor after the delay expires. They were able to watch the PF on the relay display during the start event. The PF is initially at 0.3 lag, but then decreases to...