OBO - F 8.10 Recommended Maintenance Activities

Activity: Inspect for structural integrity of the foundation, anchor bolts, supporting frame, and the transformer case.

Activity: Inspect for dirty and debris on or around insulators, bushings, cable entrances, and all transformer cooling surfaces.

Activity: Inspect for rust on all metal surfaces of the transformer case and its supporting frame.

Activity: Inspect all liquid filled transformers for signs of leaking.

Activity: Inspect all bushings, insulators, and cables for signs of cracks, discolor inc, or burned or broken connections.

Activity: For dry type transformers, vacuum dust from all windings.

Activity: For transformers using a nitrogen gas cushion, check the transformer and gas cylinder pressures.

Activity: Draw a sample of the insulating oil and have it tested for dielectric strength and acidity.

Activity: Test the resistance of the insulation between windings in the transformer, and between each winding and ground.

Activity: Inspect all alarm wiring for loose or corroded components.

Activity: Test calibration of all temperature indicators and alarms.

Activity: Inspect all liquid level gauges for clear indication of actual liquid levels.

Activity: For inert gas systems, check calibration of pressure gauges.

Activity: Inspect over current devices for evidence of damage, corrosion, dirt, or overheating.

Activity: Test the operation of all manual and automatic circuit breakers and switches.

Activity: Inspect and clean all lightning arresters. Replace any units showing signs of cracks or burns.

Activity: Inspect the dehydrating breathers for moisture saturation.

Activity: Test the operation of the pressure relief valves.

Activity: Clean, inspect, and test all auxiliary motors, fans and pumps for prosper operation and calibration.

Activity: Inspect all mechanical parts of the tap changers for corrosion, dirt, wear, and proper lubrication. Rotate the tap changer through its entire range to assure proper surface contact and tension.