Transformers are an integral part of an electric supply system and are very expensive. Regular maintenance and on-time repairing of the same is the most cost-effective way of using a transformer and ensuring its high functioning capability and efficiency in the long run.
Transformer Maintenance Tips
Maintenance of transformers is generally performed through two kinds of operations – one of which is routine and preventive and the other set is conducted as and when necessary. The conduction of the first set of operations generally reduces the chances of there being a need for the second set of operations.
Maintenance actions may be carried out on a daily, monthly, yearly, quarterly or bi-yearly basis. Let’s delve deep into the necessary transformer repairing steps for each one of them:
On a daily basis:
- Read the magnetic oil gauge of the main and conservation tanks. If the levels are unsatisfactory, then oil may need to be filled until the gauge reads the right level.
- Checking the color of the silica gel breather. Pink colored silica gel means that it needs to be replaced.
- Checking if there are oil leakages. If there are, the leak should be plugged immediately.
On a monthly basis:
- The transformer oil levels under the silica gel breather should be checked every month. If the level is found to be low, then it needs to be refilled.
- The breathing holes of the silica gel breather are to be checked and cleaned properly every month.
- If a transformer has an oil filled bushing, then the oil levels in these bushings must also be done on a monthly basis. This oil may need to be refilled, in which case, it should only be done with the transformer shut down.
On a yearly basis:
- The cooling system and all circuits of the transformer are to be checked on a yearly basis.
- The bushing must be cleaned with a soft cotton cloth and checked for any cracks or breaks.
- Check the breakdown voltage and water content of the oil on a yearly basis. If the BDV is low or the water content is higher than recommended levels, the oil needs to be purified or replaced altogether.
- A mechanical inspection of Buchholz relays needs to be done annually.
- Tightening of all wires, inspection of space heaters, and cleaning of marshal boxes from the inside are to be done every year.
- Inspection and cleaning of alarms and control switches
- All test for the various parameters of the transformer and transformer oil including specific resistance, dissolved gases, etc. are to be done every year.
On a half-yearly basis, the parameters of the transformer oil should be checked to see if it needs filtering or replacement.
Transformer Repairing Tips
Repairs must be done only by qualified professionals after taking the necessary precautions to minimize any potential accidents. Sometimes repairs may need the transformer to be shut down during working hours which can be quite expensive. For this reason, regular preventive maintenance tests should be conducted as detailed above.
Repairing a transformer instead of entirely replacing it can definitely bring down the cost. But if repairs alone are no longer enough to keep the transformer working, then replacement may be the only way to go.
When purchasing a transformer, a visual inspection must be done immediately after the shipment is received to reduce any future repairs being necessary. The installation process, if not done properly, can also incur a great loss from a faulty transformer. Immediately upon installation, the transformer must be tested to see if the working is satisfactory. Also, certain values of its parameters must be noted to be used for future reference in order to know if the transformer is functioning well as it continues to be used.
