Transformer Maintenance & Servicing

A power transformer is the most costly and essential piece of equipment within an electrical substation. So there’s a need to perform various preventative maintenance activities to ensure the transformer maintains a high level of performance and a long functional life.

Transformers require various routine maintenance tasks including measurement and testing of different parameters of the transformer. There are two main types of maintenance of transformer. We perform one group on a routine basis (known as preventative maintenance), and the second group on an ad-hoc basis (i.e. as required) meaning for getting smooth performance from a transformer, we have to perform some maintenance actions on a regular basis.

• We check the oil level in oil cap under silica gel breather in a one-month interval. If it is found the transformer oil inside the cup comes below the specified level, oil to be top up as per specified level.
• We also check the breathing holes in silica gel breather monthly and properly cleaned if required, for proper breathing action.
• If the transformer has oil filled bushing the oil level of transformer oil inside the bushing is checked in the oil gage attached to those bushing. This action also to be done monthly basis.

There are three main checks on a power transformer on a daily basis:

• Reading of (Magnetic Oil Gauge) MOG of main tank and conservator tank.
• Color of silica gel in breather.
• Leakage of oil from any point of a transformer.

In case of unsatisfactory oil level in the MOG, oil to be filled in transformer and also the transformer tank to be checked for oil leakage. If oil leakage is found take required action to plug the leakage. If silica gel becomes pinkish, it should be replaced.