Electrical transformers are an expensive and important part of any machinery. So for getting optimal performance and increased product life, it is best to conduct regular maintenance checkups on your machinery.
There are basically two types of transformer maintenance. One is done on a regular basis and the other is done at the time of urgency. If maintenance checkups are done on a routine basis then you may not have to undergo breakdown maintenance and hence save downtime.
There are a lot of different types of maintenance checks to be conducted on a power transformer. Here are some of the main transformer maintenance actions that have to be performed:
- Transformer Maintenance Checks on a Monthly Basis
- Oil level in the oil cap must be checked on a monthly basis so that it doesn’t drop below a fixed limit and hence avoid damage due to it.
- Keep the breathing holes in the silica gel breather clean to ensure proper breathing action at all times.
- If your electrical transformer has oil filling bushing, make sure that the oil is filled up to the correct level.
- Daily Basis Maintenance Testing and Checking
Here are 3 maintenance tests you should run on your transformer on a daily basis:
- Oil levels of MOG( Magnetic Oil Gauge) of the main tank and conservator tank. Always maintain to keep oil filled up to the desired level in MOG.
- Replace the silica gel if its color changes to pink.
- If any leakage is detected seal it.
- Annual Transformer Maintenance Schedule
The air fans, oil pumps along with other items that are used to cool down a transformer and control circuit must be inspected annually.
- Make sure that you clean all the bushings of your electrical transformer with only soft cotton cloth annually.
- Oil condition of OLTC should be carefully examined on an annual basis. For that take an oil sample from drain valve and test it for moisture content (PPM) and dielectric strength (BDV). If the BDV value is found low and the PPM value high, then the oil needs to be replaced.
- Make sure to clean out the inside of all of the marshalling boxes annually. Check proper functioning of the space and illumination heaters. All of the terminal connections of control and relay wiring need to be tightened at least once a year.
- All the control switches, alarms and relays along with their circuits, Remote Tap Changer Control Panel and Relay and Control Panel have to be cleaned with a proper cleaning agent.
- Examine all the pockets for the Winding Temperature Indicator and Oil Temperature Indicator if they have the necessary level of oil and make sure to top it up if required.
- The proper function of Buchholz and Press Release Device relay need to be checked on a yearly basis.
- Make sure to measure the resistive value of the earth connection and rizer should be measured annually with a clamp on the earth resistance meter.
- Transformer Maintenance on a Half Yearly Basis
Your electrical transformer needs to be checked every 6 months for IFT, DDA, flash point, sludge content, acidity, water content and dielectric strength along with how resistant it is to transformer oil.
- Maintenance of Current Transformer
A current transformer is a vital part of any equipment installed in an electrical substation for protection purposes as well as for electrical measurement. Insulation resistance of the CT has to be checked on an annual basis.
- Thermo vision scanning of primary terminals and the top dome of a live CT must be conducted on an annual basis.
- All CT secondary connections should be examined, cleaned and tightened each year to ensure that the secondary currents have the lowest resistance path.
Although your electrical transformer may keep on working smoothly, the continuous damage of the electrical vents and lack of even minimal maintenance can accelerate the inevitable failure of your transformer. To avoid this, contact our professionals at D&F Liquidators!