Routine maintenance of a transformer is essential to ensure its reliable operation and long lifespan. Here are the key maintenance tasks:

1. Daily Maintenance

Check for any unusual noises, vibrations, or overheating.

Inspect the transformer for oil leaks.

Monitor load and voltage levels.

2. Monthly Maintenance

Inspect oil levels in conservator and bushings (for oil-filled transformers).

Check for dust accumulation and clean bushings and insulators.

Verify proper ventilation and cooling system operation.

Inspect for loose connections and signs of corrosion.

3. Quarterly Maintenance

Check the silica gel in the breather (replace if discolored).

Inspect oil for signs of contamination (moisture, sludge, etc.).

Measure and record insulation resistance.

Inspect cooling fans and pumps (for forced-cooled transformers).

4. Half-Yearly Maintenance

Perform dielectric strength test on transformer oil.

Tighten electrical connections and check for thermal stress.

Verify earthing connections and grounding resistance.

5. Annual Maintenance

Conduct a detailed inspection of all components.

Test protective relays, alarms, and trip circuits.

Measure winding resistance and insulation resistance.

Perform oil filtration or replacement (if required).

Check for physical deformation of windings and core (if accessible).

Test and calibrate Buchholz relay and other protective devices.

6. Periodic (Every 3-5 Years)

Conduct complete oil testing (DGA – Dissolved Gas Analysis).

Carry out transformer turns ratio (TTR) test.

Perform frequency response analysis to detect winding movement.

Conduct sweep frequency response analysis (SFRA) if required.