Maybe I am reading the post wrong but the way I am reading it they are wondering why the smaller breaker didn't trip instead of the 1600.
I' m think the 1600 tripped because of the lower Ic rating of the main breaker and not the GFI protection built into the main.
If it tripped because it seen a ground fault from the GFI I would agree with you but I dont think they said that?
If it did tripped from seeing a small ground fault from the GFI equipment protection on the breaker then Don was right, no it wouldn't be reflected back through the motor drive.
I' m think the 1600 tripped because of the lower Ic rating of the main breaker and not the GFI protection built into the main.
If it tripped because it seen a ground fault from the GFI I would agree with you but I dont think they said that?
If it did tripped from seeing a small ground fault from the GFI equipment protection on the breaker then Don was right, no it wouldn't be reflected back through the motor drive.