How Is a Transformer Cooling System Maintained?

Published 27 Aug 2026Updated 27 Aug 20265 min readIntermediateField Service
Quick answer — Maintain the cooling system by cleaning the radiators and coolers (blocked fin/airways reduce cooling), checking and greasing the fans and their motors, ensuring the oil pumps run and the oil flows, and verifying the temperature control, thermostats and, for OFAF, the oil and air flow. A dirty or failed cooling system rapidly reduces the rating and risks overheating.
Contents
How is a transformer cooling system maintained?

Clean the heat exchangers

Radiators and coolers must be kept free of dirt, leaves and blockage so air flows freely; a blocked radiator drastically cuts the cooling.

Check fans and pumps

Inspect and lubricate the fans and motors, check the fan and pump operation (and the direction of rotation), and verify the oil level and flow for OFAF/ODAF units.

Verify control and thermal

Check the thermostats and the temperature control, confirm the cooling stages switch on correctly, and test that a loss-of-auxiliaries condition is detected and the rating is downgraded safely.

References & standards

Related

Book seriesAcademy

Related manufacturers

Prolec GE (GE Vernova) · Prolec GE Waukesha · Hitachi Energy USA · Siemens Energy · Eaton · Virginia Transformer Corp

Related components

Transformer cooling systems Protection, monitoring & diagnostics
Technical content is prepared from engineering references, standards frameworks, manufacturer documentation and industry sources. Contractual or compliance decisions should refer to current official standards. TransformerPath Technical Editorial.
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