- Breather Definition: A breather controls the moisture level entering a transformer when oil expands or contracts, using silica gel to absorb moisture.
- Conservator Tank Purpose: A conservator tank provides space for the expansion of transformer oil and acts as an oil reservoir.
- Explosion Vent Function: The explosion vent in a transformer releases excess pressure to prevent damage to the transformer tank.
- Radiator Function: The radiator cools the transformer oil by circulating hot oil through its large surface area and cooling it with forced air.
- Oil Cooling Process: Hot oil from the transformer circulates through the radiator, where it cools before re-entering the main tank, facilitated by valves and forced air from fans.
For providing long service life to the transformer, different transformer accessories get fitted with it. These transformer accessories should also be included in our study for better understanding transformer operation and maintenance.
Breather of Transformer
When the temperature of transformer insulating oil changes, the oil expands or contracts, causing air exchange when the transformer is fully loaded. As the transformer cools, the oil level drops, and air is absorbed. This process is called breathing, and the device that manages it is the breather. Silica gel breathers control moisture levels entering the equipment during these volume changes.
Conservator Tank of a Transformer
The conservator tank is a cylindrical tank on top of the transformer’s main tank. When the transformer is loaded or the ambient temperature rises, the oil temperature and volume increase. The Conservator tank of transformer provides space for this oil expansion and serves as an oil reservoir.
Explosion Vent of Transformer
The explosion vent in a transformer prevents damage by releasing excess pressure generated inside the transformer.
Construction of Explosion Vent of Transformer
This is nothing but a bent pipe with thin aluminium diaphragms at both ends. A wire mesh is provided at lower end of the explosion vent to prevent the pieces of rutted diaphragm from entering the tank. A wire mesh is also provided at upper end of vent pipe to protect mechanical damages of upper diaphragm.
Near the lower end, a small oil level indicator is provided to lower diaphragm ruptures; transformer oil rises in the vent pipe and is visible through the indicator indicating the failure of the lower diaphragm. If even after brushing the lower diaphragm, there is enough pressure and is not reduced, the upper diaphragm then bursts out to give way to release the inside pressure of transformer tank by thronging out oil and gases. In this way, explosion vent of transformer prevents mechanical damage to the transformer tank.
Sometimes, upper portion of conservator tank is connected with explosion vent with an equalizer pipe with or without a valve.
Radiator of Transformer
Oil immersed transformer is always provided with radiator. In case of electrical power transformer, the radiators are detachable and transported separately to the site. The upper and lower portions of the radiator unit is connected with the transformer tank via valves. These values are provided to prevent draining of oil during detaching a radiator unit from the transformer for cleaning and maintenance purposes.
Operation and Purpose of Radiator in Transformer
When the transformer is loaded, hot oil rises in the main tank and enters the radiator through the upper valve. The radiator’s large surface area cools the oil, which then returns to the transformer through the lower valve. This convectional oil flow continues, and the cooling effect can be boosted by using fans to blow air over the radiator.
