HSE has recently carried out several investigations into dangerous occurrences that resulted from a failure of industrial uninterruptible power supply (UPS) systems at onshore major hazard establishments.
Some of these incidents have led to localised fires within industrial UPS systems due to failures of either capacitors or batteries with smoke, excessive heat resulting in failure of the static switch and a failure to provide emergency power via a second UPS.
Other incidents, due to component failures and outdated firmware, have led to unplanned shutdown of a chemical processing plant which subsequently on start-up led to an unplanned release of toxic substances into the environment, and additional demand placed upon other safety related systems.
The HSE investigations identified in all cases that:
The information for maintenance included in the original equipment manufacturer’s operating and maintenance instructions did not provide adequate information to allow the continued safe and reliable operation of the industrial UPS systems prior to the incident.
Source: HSE.