Energy & Power, Heating, Cooling & Drying

The Right Way to Maintain Power Transformers

Phil Black - PII Editor 22/01/2020

284 2 minutes read

Key points

Listen to this article

Power transformer is an expensive piece of machinery that always needs to provide optimal performance. Just like any other electrical and mechanical tool, they also need proper maintenance from time to time to maintain a good performance. You may have to deal with bigger and more expensive breakdown maintenance if you don’t follow the proper way to maintain power transformers.

To Do on a Daily Basis

Though it may feel like a bit of a drag to regularly check the transformer, it is important and doesn’t take much time. There are only three things you need to test. They can cause bigger troubles if you don’t find and solve them on time. Besides, all three of them don’t require you to have technical knowledge of the transformer.

Check if oil levels of Magnetic Oil Gauge are correct. Make sure it’s not below the desired level.
Check if there is any leakage on any part of the transformer and seal it at first priority.
Check the colour of the Silica. Replace it if it’s changed to pink.

To Do on Monthly Basis

Choose one date of the month and test the transformer for three things. These issues are also very important but don’t need to be checked regularly. One can skip the daily test of the transformer, but te monthly check-up shouldn’t be ignored at any cost.

1. Oil in Oil Cap

Just like the magnetic oil gauge, you also need to check the oil in the Oil Cap. This is to ensure that oil doesn’t get below the fixed limit where it starts causing damage to the transformer.

2. Clean Breathing Holes

You have to ensure that the Silica Gel Breather is clean all the time. It affects the breathing action of the transformer if its breathing holes get dusty.

3. Bushing Oil Level

Another and one of the most important monthly check-up is ensuring the Bushing oil level. You can check it in the oil gage attached to the Bushing of the transformer. Fill the Bushing with oil if it’s less than the required level.

To Do on Annual Basis

There are a lot of things that need to be done once a year. This step requires one to have technical knowledge of the power transformer. If you don’t have that kind of skill, you can get help from someone who deals with power transformers in the UK. Here is what you need to do every year for the maintenance of power transformers.

Measure the Rizer on the earth resistance meter every year.
Thoroughly clean Bushings with a soft cotton cloth.
Clean Marshalling Boxes from the inside. Also check the illumination and space heaters.
Check if Winding and Oil Temperature Indicators have the right amount of oil.
Examine the oil condition of OLTC.
Ensure Press Release Device Relay and Buchholz are functioning properly.
Test all circuits, including switches, relays, and alarms.