Overheating of transformer occurs when the temperature of the transformer rises above the standard operating temperature of the transformer. The standard operating temperature of a transformer is between 20°C to 30°C above the ambient temperature. Losses in the different part of the transformer are converted into the heat resulting raise in temperature of the transformer.
If the temperature rises above standard safe range, it can cause significant damage to the insulation, winding, core, insulating oil, bushing e.t.c and leading to failure, fire or explosion in transformer. The hottest part of the transformer is the oil on the top of the core. Overheating can occur due to overloading, insulation failure or malfunctioning of the cooling system.
Effect of Overheating of a Transformer
Overheating in a transformer can cause very serious problems. All the effect of overheating of a transformer are explained below.
- If the temperature rises above the standard temperature rating, insulation of transformer can break down leading to damage to the winding, core, insulation, insulating oil or other components.
- Due to overheating, insulating oil in the transformer can break down leading to failure, fire or explosion in transformer.
- Equipment damage due to overheating can be costly to repair or replace resulting financial loss.
- Transformer operating at high temperature results reduced lifespan due to accelerated aging of the components.
- Overheating of the transformer can cause a fire in transformer which can spread to other equipment i.e overheating in a transformer has risk of fire.
- Overheating of transformer can lead to power outages that can affect homes, businesses, hospitals and other critical facilities. This lead to financial losses, production downtime, even loss of life or deaths in hospitals.
- Sometimes overheating lead to explosion in transformer that results financial loss, power outage and damage to the environment.
Reasons for Overheating of a Transformer
- Overloading the transformer
- Low insulating oil level in a transformer reduce effective cooling.
- Moisture in the transformer oil reduces its insulating properties.
- Failure or malfunctioning of the cooling system.
- Damaged or wore insulation of a transformer lead to arcing and heat up.
- Current appeared in the neutral of the transformer due to unbalanced load resulting.
- Excessive fluctuation of load on a transformer lead to uneven linking of magnetic field between secondary winding and uneven generation of electric field.
- Leakage current through weakened part of the insulation.
Measure prevention of overheating of a transformer
- Managing the load properly ensures that transformer operates at rated capacity.
- Proper ventilation and cooling i.e proper flow of air and circulation of insulating oil.
- Maintaining oil level in main tank and conservator tank ensures proper cooling of the transformer.
- Maintaining temperature of transformer ensuring that transformer operating within standard safe range.
- Regular inspection and maintenance ensuring proper operation and proper load management.
- Using transformer of required KVA rating.
- Connecting the neutral to the earth ensuring zero potential.
Conclusion
Hope, you have clearly understand about overheating in a transformer, its effect, reason and prevention. Make sure to leave your opinion and suggestion about this post in the comment section below.