UPS - MAJOR PM VISIT

Measure and Record the following:           

  • Rectifier Input voltages & currents.
  • Inverter Output voltages & currents.
  • Bypass Input voltages & currents.
  • System Output (Critical Buss) voltages & currents.
  • Rectifier Output voltages and currents.
  • Delta voltages (difference between Bypass & Inverter Output)
  • Bypass and Inverter frequency.
  • Thermal Scan UPS for hot spots.
  • Compare front panel meter readings with above measurements and verify 3% accuracy.
  • Check alarm / status indicators and remote status panel, note any deficiencies.
  • Inspect air filters and replace if necessary.
  • Check all fans for free and quiet rotation.
  • Perform operational inspection of Static Switch / Transfer circuitry.
  • Vacuum and clean UPS interior and exterior.
  • Inspect, test & clean all major sub-assemblies and replace defective or marginal components.
  • Check all electrical terminations for proper tightness and signs of overheating.
  • Perform mechanical inspection of all transformers, filter capacitors and wiring.  
  • Check unit Power Supplies,  AC / DC protection settings, and voltage waveforms.
  • Verify correct Inverter free‑run frequency.
  • Simulate Input power failure and verify proper unit operation (customer permission required).
  • Provide one copy of recorded data.