ABB PMS Blackout Recovery Investigation

Anonymized vessel case. Automatic blackout recovery was not functioning correctly. The investigation showed that the problem was not one central PMS failure: several generating sets had independent readiness, control and feedback faults that prevented the recovery sequence from completing reliably.

We investigated the generator readiness and control conditions individually rather than treating the event as one PMS fault. Findings included unreliable tachometer / speed-feedback behaviour affecting Generator 4 synchronization, failed governor power supplies affecting Generators 4 and 5, a recurring Generator 3 Trip Fail associated with HGAU-20C / HGAU-20B alarm-control PCBs, and an unresolved Generator 2 Governor Fail requiring further controller-log review and governor-specialist input.

The automatic recovery problem was being driven by several independent generator-side faults. The PMS could not complete start, synchronization, load sharing and recovery reliably while those generating sets were not individually ready for automatic control.

This distinguished the generator readiness/control defects from a single central PMS-logic failure.

The investigation defined the separate faults that had to be repaired before automatic blackout recovery could be considered reliable. Additional troubleshooting, spare parts and generator-control repairs remained necessary.

The system was not represented as fully restored at the end of this diagnostic scope; manual supervision remained required until the outstanding generator faults were corrected.

Blackout-recovery faults should not automatically be treated as PMS failures. Proving which generating sets are actually ready to start, synchronize and accept load prevents unnecessary work on the central control system and gives the vessel a clear corrective-action list.