Wiring of generator transformer set of a certain unit

1. The current in phase A is too large and the phase BC is too small, indicating that phase A is a faulty phase

2. There are negative sequence current and zero sequence current, indicating that there is a ground fault

3. The air temperature at the generator outlet increases, indicating that the ground short circuit point is at the generator outlet

The result is: phase A ground fault at the generator outlet.

Then it is necessary to reduce the load, then shut down the machine, check the A-phase fault condition during a power outage, and carry out maintenance.