We recently attended a Hospital in South Wales where a GE M-PACT mk2 ACB which had failed during an auto changeover left the hospital without power for a short time.
We investigated the ACB on a workbench by performing electrical tests to try and simulate the fault. The ACB failed numerous times on the bench and the decision was made to replace the ACB mechanism with a new spare mechanism that site had available.
Once the mechanism was replaced the issue was no longer present and the ACB was operated numerous times manually and electrically on the bench with no re-occurrence of the fault.
Highlighting the importance of good ACB maintenance at sites where continuity of power is required.
If your facility has ACBs that require a service, please do not hesitate to get in touch.