Hello Professionals,
When the turbine (GE frame 9E, 115MW) is running and online, and we have 2 units of 88WC (cooling water motor 1&2) where one of them is running. For instance 88WC-01 is running and set to lead. It is observed that 88WC-01 would trip (display fault) after a short while and then switch running status to 88WC-02 while its still leading. Same happens when 88WC-02 is set to lead. It trips after a while and switches the running status to 88WC-01 to run while 88WC-02 still leads and displays fault on the HMI. We have checked the contactors for arcs or partial contacts and even changed out contactor kits in both motor withdrawal buckets, but the problem still persists.
Please your advice would be appreciated.
When the turbine (GE frame 9E, 115MW) is running and online, and we have 2 units of 88WC (cooling water motor 1&2) where one of them is running. For instance 88WC-01 is running and set to lead. It is observed that 88WC-01 would trip (display fault) after a short while and then switch running status to 88WC-02 while its still leading. Same happens when 88WC-02 is set to lead. It trips after a while and switches the running status to 88WC-01 to run while 88WC-02 still leads and displays fault on the HMI. We have checked the contactors for arcs or partial contacts and even changed out contactor kits in both motor withdrawal buckets, but the problem still persists.
Please your advice would be appreciated.