Types of Oil Filled Transformers
Oil-Filled Transformers are classified into two types: self-cooled and forced-cooled.
1. Self-Cooling Type
Self-cooled transformers are naturally cooled using internal oil and a cooling system. Heat is dissipated through a radiator or similar device attached to the tank. Oil-Filled Transformers are the most common type of transformer and are widely used in power transmission and distribution systems.
2. Forced Cooling Type
Forced-cooled transformers are transformers in which oil is forcibly circulated through a cooling system. Forced circulation can enhance the cooling effect. Oil is often circulated by pumps or fans, and is suitable for use in high-load or high-temperature environments.
Other Information on Oil Filled Transformers
1. Allowable Temperatures for Oil Filled Transformers
If an Oil-Filled Transformer overheats, there is a risk of insulation failure due to forced deterioration of the insulating oil. In the worst case, a fire may result. Therefore, keeping the operating temperature below the allowable value is an important item for management.
The maximum allowable temperature for Oil-Filled Transformers, which are widely used in general, is 105°C. However, since it is also affected by external temperatures and temperature differences, it is controlled at around 95°C or lower.
2.Treatment of Oil-Filled Transformers Under the Fire Service Law
Mineral oil used in Oil-Filled Transformers is generally classified as Petroleum No. 3. Since the volume of insulating oil in a large Oil-Filled Transformer exceeds 2,000 liters, the oil alone is classified as a hazardous material under the Fire Service Law. However, when the transformer is connected to an electrical circuit, the Electricity Business Law applies and it is no longer treated as a hazardous material.
If an old transformer is dismantled and disconnected from an electric power line, it is treated as a hazardous material. Since various specific cases can be assumed, it is necessary to check with the fire department or other authorities to determine the appropriate action to be taken.