Coresystems’ trained technicians regularly test your UPS systems’ safety functions, control functions, batteries, and connections to ensure proper operation. This also includes load testing and determining the backup time available on your batteries, spare parts, or time and material services which are available for customers who do not have a full maintenance contract. Last but not least, detailed reports are provided after every PM visit.
Regular equipment testing should be part of a facility’s UPS maintenance schedule. The testing framework and its activities are customizable and significantly depend on client requirements, but most typically include the following procedures:


  • Visual inspection of equipment for loose connections, burned insulation, or any other signs of wear.
  • Functional checkout and test of the UPS diagnostic systems. Check of environment, temperature, dust, moisture, room vents, etc.
  • Inspection of all power cabling for abrasions and burn spots, signs of overheating, swelling, leaking, etc. Examination of printed circuit board alignments.


  • Replacement of the air filters. Visual check for liquid contamination from batteries and capacitors.
  • Cleaning and vacuuming of UPS equipment enclosures.
  • Check of HVAC equipment and performance related to temperature and humidity.
  • Check and calibration of each system, to include switchgear and circuit breakers, meters, and alarm levels for frequency, voltage, current, transfer, trip, alarm, etc.
  • Cleaning and tightening all power connections at the input and output terminals, at all circuit breakers, and at the terminal posts and fuses on the rectifier and inverter legs.


  • Conduction of 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.
  • Provisioning of 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.
  • Off-line load test the UPS system to ensure that the system is completely functional.


  • Control battery replacement: if the control batteries have been used without an inverter or bypass
  • AC power, they may need replacement sooner.
  • Testing the UPS transfer switches, circuit breakers, and bypasses.

Whenever UPS testing occurs, our technicians place the system into bypass mode or transfer the load to the redundant system, if designed this way. They are especially cautious when maintaining the equipment to prevent an outage. Our technicians are also familiar with most standard UPS equipment, manufacturers’ testing requirements, specifications, and of course, safety precautions.

  • Caterpillar
  • Honda
  • Kipor
  • Kohler
  • Kubota
  • Onan
  • Perkins
  • Yamaha
  • Yanmar
  • SDMO
  • FG wilson
  • Olympain
  • Iveco
  • Leroy somer
  • Mitshubishi
  • Volvo
Written by Praveen

UPS Maintenance