The Cause of Common Fires in Oil Type Transformers

The oil type transformer has a large amount of insulating oil and a certain amount of combustibles such as cardboard, cotton yarn, cloth, and wood. These organic combustibles are prone to fire and explosion if exposed to high temperatures, sparks and arcs, which may cause a fire hazard in the transformer. For indoor transformers with oil content >600Kg, oil storage pits should be provided.

1. Due to the poor quality of the transformer manufacturing, or the maintenance error, or the long-term overload operation, the internal coil insulation is damaged and a short circuit occurs.

2. Poor connection of the joint causes excessive contact resistance, resulting in local high temperature fire.

3. The core insulation is damaged, the full flow increases, and the temperature rises, causing the internal combustibles to burn.

4. When a short circuit or overload occurs in the electrical equipment, if the protection device of the transformer fails or the setting is improper, it will cause the transformer to overheat.

5. The oil quality of the transformer is degraded, or the oil tank is leaking or lacking oil, which affects the thermal cycle of the oil, so that the heat dissipation capability of the oil is lowered, resulting in overheating and fire.

6. The transformer is struck by lightning, and an electricarc or electric spark is generated to ignite the combustibles.

7. If the animal is connected across the low-voltage bushing of the transformer, it will cause a short-circuit fire.

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