Generator Stator Cooling Water Pump Failure. 12 Failures of 1 Pump.

Repeated failures of a 991 MVA generator's stator cooling water pump operating in an 1800 MW power plant will be discussed. The purpose of this critical pump is to provide cooling water to the stator bars within the generator. Eventually, twelve failures were attributed to this one 100 HP, API 610 pump over the course of two years, before the correct root causes were identified and implemented.

This presentation follows the missteps of incorrect modifications, maintenance and assumptions made about the pump design which prevented problem resolution. Then the correct steps taken to determine the actual root cause of the multiple pump failures will be presented. The correct steps included implementing effective modifications to the pump and to altering the pump maintenance procedures to end the failures.