For any electrical supply station, the power transformers are one of the main electrical equipment and hence it is essential that necessary care must be taken so that it can give optimum performance.
Regular preventive maintenance activities can prevent you for transformers repair activities which may lead to unplanned power supply breakdowns at times.
Daily basis maintenance
Following are few daily basis check and monitoring needed for transformers:
- Check the reading of magnetic oil gauge
- Check the color of silica gel
- Check if there is any leakage of transformer oil
Following are few maintenance activities that you need to perform on monthly basis.
- In case, the oil level in silica gel breather is below the specified limit then fill the oil to its top level
- Clean all the breathing holes in proper manner so that transformer can easily breathe.
- Also, check the transformer oil level and take necessary action.
Following are few of the yearly maintenance for your power transformer.
- All the control circuits related with auto, remote and manual functions of the cooling system must be thoroughly checked. If any problem is found then you need to investigate the cause and address the problem.
- Clean all the transformer bushings and check for any cracks.
- You need to examine the oil condition of the OLTC by taking the sample of oil and measure its dielectric strength and moisture content. If found out of range then need to replace oil.
- Perform the mechanical inspection of relays.
- Clean all marshalling boxes from inside and check all space heaters are functioning ok. All terminal connections are proper.
- Clean all the relays, control switches, alarms and also all the associated circuits. By using suitable cleaner.
- Check the pockets for WTI, OTI and if needed then replenish the oil.
- Check the function of various pressure release devices and relays so that you can ensure that concerned relays of the remote panel are functioning properly.
- Measure the insulation resistance and also transformer’s polarization by using any battery operated megohm meter of 5 KV range.
- Measure the resistance of earth connection and also riser by using a clamp on earth type of resistance meter.
- Dissolve gas analysis must be done for transformer Oil annually for 132 KV rating transformer and once in two years for transformer below rating of 132 KV transformer.