How to Clean Transformer Radiators & OFAF Oil Coolers for Stable Long-Term Operation

Transformer radiators and OFAF forced air coolers are the core heat dissipation components for power transformers. After long-term outdoor operation, dust, leaves, industrial sediment, salt fog and bird droppings will accumulate on aluminum fin surfaces. Blocked fins drastically cut heat exchange efficiency, raise transformer oil temperature, trigger overload alarms and even accelerate insulation aging. Regular cleaning of transformer radiators is a low-cost but essential maintenance procedure to extend transformer service life.

Why Dirty Radiators Damage OFAF Cooling Systems

Reduced air circulation

Dust layers cover cooling fins, block airflow from axial fans. The forced air designed for OFAF cannot fully contact oil tubes, resulting in insufficient heat dissipation.

Higher operating temperature

Oil temperature rises continuously; transformers lose partial overload capacity, easily hitting temperature protection limits in summer high ambient temperature.

Extra energy consumption

Control systems will start all fans and standby pumps continuously to compensate poor cooling, raising long-term power operating costs.

Corrosion acceleration

Moisture trapped inside dust corrodes aluminum fins and welds, causing fin peeling or oil leakage over time, especially for coastal C5-M environment equipment.

Safe Step-by-Step Guide to Clean Transformer Radiators & OFAF Coolers

Pre-clean Safety Preparation

Switch off and lock cooling fan & oil pump power supply; implement safety isolation procedures.

Cover transformer bushing, control cabinet, junction boxes and wiring terminals with waterproof protective covers to avoid water ingress.

Check radiator pipelines, valves and welds for existing leakage before cleaning.

Two Main Cleaning Methods

1. Dry Cleaning (Light dust, regular monthly maintenance)

Use low-pressure air blower to blow dust from fin gaps, blow from top to bottom.

Remove large debris such as dead leaves and plastic fragments manually first.

Soft brush to sweep stubborn surface dust without bending thin aluminum fins.

Suitable for dry inland substations with light pollution.

2. Low-pressure Water Washing (Heavy dust, industrial/coastal sites, quarterly deep cleaning)

Use low-pressure clean water (no high-pressure water gun to avoid bending fins) mixed with neutral industrial cleaning agent.

Spray evenly on fin surfaces, wait 3–5 minutes to dissolve sticky dirt and salt residue.

Rinse thoroughly from top down until water flows clean without grey stains.

Leave fans running for 30 minutes after cleaning to fully air-dry fins and internal gaps.

Critical Cleaning Notes for OFAF Oil Coolers

Never use high-pressure impact washing: Aluminum cooling fins are thin and easy to deform, which creates permanent airflow blockage.

Avoid acid or alkaline strong detergents: They will damage anti-corrosion coating (C3 / C5-M coating) and cause early rust.

Do not clean during rainy days or high humidity; ensure full drying before removing waterproof covers.

After cleaning, inspect all fan groups and submersible oil pumps for abnormal noise during test run.

Maintenance Cycle Reference

Inland ordinary substation: Dry clean monthly, water deep clean every 6 months

Heavy industrial / chemical plant area: Deep clean every 3 months

Coastal salt fog environment (C5-M anti-corrosion cooler): Monthly light cleaning, quarterly washing with anti-salt cleaning fluid