2) CONTACTOR DRIVER
MDI-PRC Code = 75
- Cause: This alarm occurs when the voltage on the Main Contactor is
smaller than expected: this means that the Main Contactor Coil
has a null voltage when supplied.
- Remedy: Check the coils of the Main Contactor (CNA#1) is not short
circuited. If it isn't, probably it is necessary to substituite the
controller because the driver of the Main Contactor is broken.

hope it helps , regards