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Recent content by T247

  1. T247

    Wye-Wye Transformer on Low Resistance Grounded System

    We can't access the X0 bushing to the 13.8-4.16 kV transformer since the equipment is energized.
  2. T247

    Wye-Wye Transformer on Low Resistance Grounded System

    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...
  3. T247

    Sync Motor PF Trip

    They replace the Sync-Rite device on the diode wheel and they were able to get the motor to run.
  4. T247

    Sync Motor PF Trip

    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.
  5. T247

    Sync Motor PF Trip

    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...
  6. T247

    Sync Motor PF Trip

    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...
  7. T247

    Sync Motor PF Trip

    No, just power factor trip
  8. T247

    Sync Motor PF Trip

    Thanks, I'll have this checked out. For a brushless sync motor, what happens if the field leads are reversed?
  9. T247

    Sync Motor PF Trip

    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...
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