What are the possible causes of failure of transformer?

What are the possible causes of failure of transformer?

Cause of Failure

• Misapplication.
• Vibration.
• High Operating Temperature.
• Lightning or Line Surges.
• Overloading.
• Care of Control Equipment.
• Lack of Cleanliness.
• Care of Idle or Spare Equipment.

What is the purpose of oil in transformer?

Transformer oil is used to insulate high-voltage electrical infrastructure such as transformers, capacitors, switches and circuit breakers. Transformer oils are designed to operate effectively at very high temperatures, cooling, insulating, and stopping corona discharges and arcing.

What challenges are associated with the transformer oil?

However, the main concern related to mineral oil is overheating, overloading, short circuits that reduce the shelf life of the transformer unit and restrict its function as a reliable coolant.

What are the main problem areas in Transformers?

Electrical failure typically involves line surges, which is a very common cause of transformer failure. Voltage spikes, switching surges and line faults are a few common culprits of electrical failure.

Why would a transformer leak oil?

Transformers are susceptible to oil leakage which can be caused by corrosion or faulty welds. This leads to breakdown of fins, flanges, valves, seals, and pipework. These costly implications can be quickly and simply prevented using the Belzona Transformer Leak Sealing Solution.

What should be the reason for low dielectric strength of oil in a transformer?

The dielectric strength may be drastically reduced by water supply or increased amount of foreign particles. Pure transformer oil is usually free from water and mechanical impurities and its breakdown voltage is greater than 60 KV(kilowatt).

Is transformer oil harmful?

The main constituent of transformer oil is polychlorinated biphenyl (PCB) which is responsible for producing toxicity in humans. Chronic exposure with PCB may cause some toxicity such as hepatotoxicity and neurotoxicity.

What effects are produced in a transformer by change in voltage?

Transformers change the voltage of the electrical signal coming out of the power plant, usually increasing (also known as “stepping up”) the voltage. Transformers also reduce (“step down”) the voltage in substations, and as distribution transformers.

What causes low voltage transformer failure?

Low-voltage transformers do not wear out. Usually, a transformer fails only after another part in the electrical circuit shorts to ground or draws an unusually high amperage. In these cases, replacing the transformer without first finding and correcting the fault will only cause the transformer to fail again.

What is causes of failures of cores?

The most common causes of mechanical degradation in cores are inadequate core pressure applied in manufacture, core pressure reduction in service due to relaxation of the core support structure, core vibration, back-of-core looseness, and mechanical damage causing smearing of the core surface at the bore.

How do you maintain an oil-filled transformer?

Daily maintenance schedules for oil-filled transformers should include oil and temperature checks. Inspect the ambient, winding and oil temperatures to see if they’re within the normal range. The oil level gauge should vary with changes in temperature and, if it’s a magnetic model, it should respond to the presence of a magnet by rotating.

What happens if the oil level is too high in transformer?

If the oil level is too high, it could cause over pressurization when the oil expands. If the transformer is equipped with a constant-pressure nitrogen oil preservation system, then pressure gauges are included to measure the pressure of the gas blanket and the nitrogen in the make-up bottle.

Why is my oil-filled transformer so loud?

Noise level is often a more relevant performance indicator for dry type transformers. However, if your oil-filled model operates loudly, it’s essential to figure out what might be causing this phenomenon. High noise levels often originate from the transformer core, cooling system or coils.

What is the minimum breakdown voltage of transformer oil?

Dry and clean oil gives BDV results, better than the oil with moisture content and other conducting impurities. Minimum breakdown voltage of transformer oil or dielectric strength of transformer oil at which this oil can safely be used in transformer, is considered as 30 KV.