Essential Maintenance Tips for Transformers

The transformer is expensive electrical equipment and plays an important role in the power grid. Therefore, to extend the product life and get optimal performance, it is needed to conduct regular maintenance checkups on your machinery.

Transformer maintenance is divided into 2 types: regular basis maintenance and urgent maintenance. If you do the routine basic checkups, you may not have to deal with breakdown maintenance and save downtime.

The followings are some of the main transformer maintenance actions that should be performed:

Transformer Maintenance Checks on a Monthly Basis

1. Checking the oil level in the oil cap on a monthly basis so that it doesn’t drop below a fixed limit and hence avoid damage due to it.
2. Keeping the breathing holes in the silica gel breather clean to ensure proper breathing action at all times.
3. Make sure that the oil is filled up to the correct level If your electrical transformer has oil filling bushing. 

Daily Basis Maintenance Testing and Checking

 The followings are 3 maintenance tests you should do on your transformer on a daily basis:

1. Oil levels of MOG of both the main tank and conservator tank. Always maintain to keep oil filled up to the desired level in MOG.
2. If its color changes to pink, please replace the silica gel
3. If any oil leakage is detected.

Annual Transformer Maintenance Schedule

The air fans, oil pumps along other items that are used to reduce the temperature of a transformer and control circuit must be checked annually.

1. All the bushings of your electrical transformer should be cleaned with only soft cotton cloth annually.
2. The oil condition of OLTC should be carefully inspected on an annual basis. For that case, please take an oil sample from the drain valve and test it for moisture content (PPM) and dielectric strength (BDV). If the BDV value is low and the PPM value is high, then the oil needs to be replaced.
3. The inside of all of the marshaling boxes is ensured to be cleaned annually. Test proper functioning of space and illumination heaters. You need to tighten all of the terminal connections of control and relay wiring at least once a year.
4. All the alarms, control switches, and relays along with their circuits, Relay, and Remote Tap Changer Control Panel and Control Panel have to be cleaned with a proper cleaning agent.
5. Check all the pockets for the Winding Temperature Indicator and Oil Temperature Indicator if they have the necessary level of oil and ensure to top it up if required.
6. The proper function of the Press Release Device and Buchholz relay need to be checked on a yearly basis.
7. 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

You should check your electrical transformers every 6 months for IFT, DDA, flash point, sludge content, water content, acidity, and dielectric strength along with how resistant it is to transformer oil.

Maintenance of Current Transformer

A current transformer is an important 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 inspected on an annual basis.

1. Thermometer vision scanning of primary terminals and the top dome of a live CT must be checked on an annual basis.
2. All CT secondary connections should be checked, cleaned, and tightened each year to make sure 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 MBT.

We ensure to supply the best products and wonderful maintenance at a reasonable price. To be consulted, please contact freely via Email, Zalo, Hotline. We are willing to provide strong support for your projects.