UNINTERRUPTIBLE POWER SUPPLY (UPS) SYSTEM PREVENTIVE MAINTENANCE - SCOPE OF WORK

  Minor PM  

Visual Inspection:

• Inspect overall unit operation
• Inspect display function
• Inspect alarm history
• Inspect cooling fans
•  

Measure, check, record, and adjust if necessary:

• Input voltages and currents
• DC voltage and current
• AC ripple voltage and current
• Output voltages and currents
• Breakers
• Check and replace all filters (as required)
  

Perform complete thermal scan of all possible electrical connections

Remove all foreign debris from equipment compartments, where applicable

Check and record room ambient temperature and verify proper operation of ventilation equipment

  Major PM  
  – Includes all tasks done during Minor PM visit plus the following:   

Visual Inspection:

• Clean and inspect all logic cards

• Inspect all connectors

• Inspect major components

• Inspect cables and wiring harnesses

• Verify that all diagnostic tests function properly

• Verify all protection settings

• All power supply voltages
• Check and verify manual transfers from UPS system to normal bypass and from normal bypass to UPS system
• Check all primary and secondary circuits for proper torque
• Check all electrical connections for proper torque and general condition
• Check all system level alarms
• Check power capacitors for swelling and leaking oil
• Check and verify automatic transfers
• Check inverter and rectifier snubbers for burned or broken wires

Documentation of inspection with recommendations for any corrective action deemed necessary will be provided on both Minor and Major PMs