UPS Maintenance Checklist

Simply providing an uninterruptible power system (UPS) does not necessarily ensure an institutional or commercial facility’s equipment is protected from power-supply fluctuations and distortions. Maintenance and engineering managers must factor in regular testing and maintenance of a facility’s UPS to ensure it remains in peak operating condition, protects critical systems, and keeps them reliably operating as designed.

Regular equipment testing should be part of a facility’s UPS maintenance schedule. Such a schedule might include the following elements:

Quarterly:

• Visually inspect equipment for loose connections, burned insulation or any other signs of wear.

Semiannually:

• Visually check for liquid contamination from batteries and capacitors.

• Clean and vacuum UPS equipment enclosures.

• Check HVAC equipment and performance related to temperature and humidity.

Annually:

• Conduct thermal scans on electrical connections to ensure all are tight and not generating heat, which is the first and sometimes only indication of a problem. A non-evasive diagnostic tool helps technicians identify hot spots invisible to the human eye. Technicians should retorque if thermal scan provides evidence of a loose connection
• Provide a complete operational test of the system, including a monitored battery-rundown test to determine if any battery strings or cells are near the end of their useful lives.

Biannually:

• Test UPS transfer switches, circuit breakers and maintenance bypasses.

If a generator is part of the building’s emergency-power system and feeds the UPS, it also will need to be tested monthly or quarterly. Most facilities have a generator-maintenance schedule in place in which testing frequency is defined.

A UPS typically is sized to carry the load for a short period of time. Longer outages require backup-power generation to maintain critical services. Each facility is unique, and managers need to develop a maintenance schedule to suit each site’s specific needs.

UPS Maintenance Checklist