Maintaining transformers in a healthy and functional state is key to ensuring electrical system reliability. We have all fallen victims of lights going off when we are busy working on some online project or in the middle of a nice movie. Such unexpected power interruptions come as a result of poorly maintained transformers. Management of risk failures of transformers is divided into two major categories. The first schedule of maintenance is the routine basis, and the second is as when required. However, if keen interest is put on regular maintenance, there may be no provision for conducting any forms of emergency maintenance. Routine checks up may be done on a monthly, quarterly, or year basis.
Daily Checking and Maintenance
Three major things are to be checked on a power transformer daily:
- The magnetic oil gauge (MOG) of the main and conservator tank must be read to ensure it is at the required standard position. Oil must be refilled if that is not the case.
- The transformer has to be assessed for leakages at any point.
- The colour of the silica gel in the breather must be checked. If you notice a pinkish colour, it is time to replace it.
Monthly Routine Maintenance
Just like a car needs regular service after certain mileage, specific maintenance actions must be taken on a monthly basis to avoid unexpected breakdowns.
- Oil levels within transformer cups under the silica gel breather must be checked in intervals of one month. If low, the kit must be topped to set it back to the required standard. The oil filling process must be done when the transformer is shut down.
- The silica gel breather has holes that must be check when replacing oil. They must be cleaned to allow proper breathing.
Yearly Routine Check Up
- The cooling system of a transformer has to be checked on an annual basis. The process involves checking the air fans, oil pumps, manual faction, and their control circuit. If the condition of the system is unfit to perform, the physical condition of fans and pumps together with their control unit has to be investigated to determine the fault.
- All the bushings must be cleaned using a soft cotton cloth. The bushing should be checked for any cracks when cleaning.
- The resistivity action of the rizer and earth connection must be measured using a clamp on the earth resistance meter.
With all these standard maintenance measures, a transformer is able to supply electricity in a region for a long time without experiencing unnecessary breakdowns