(1) Insulation damage
a. Deterioration of coil insulation. b. The quality of the oil is not good, and the amount of oil is too small. c. Deterioration and damage of the core insulation. d. The insulation layer is damaged due to careless maintenance.
Transformer manufacturer
(2) Poor contact. Local overheating, coil insulation damage, short circuit or open circuit, high temperature, arc, etc. will quickly decompose the insulating oil, produce a large amount of gas (80% hydrogen), and the pressure will suddenly rise. Loose bolts (transformers often work due to shock loads, and contact looseness due to vibration), loose welding, and damage to switch contacts.
(3) Lightning overvoltage. The lightning voltage passes through the insulating layer of the transformer, burning the transformer and causing a fire.
(4) The load is short-circuited. If the protection system fails or the setting value is adjusted, it may cause the transformer to burn out. To set up a short-circuit protection device, you need to choose a melt. When the transformer is short-circuited, the high-voltage side can quickly fuse, and when the transformer is short-circuited or there is a serious overload, the low-voltage side can be fuse.
(5) Overheating of the transformer will affect the life of the transformer. (For example, the normal operating temperature is 90°C and the transformer life is 20 years. The temperature rises to 105°C requires 7 years of life. If the temperature rises to 120°C, the life is only 2 years. The serious problem is fuel injection combustion or explosion. Transformers The causes of overheating include poor contact, high contact resistance, long-term heavy load operation, coil heating, excessive voltage, increased iron loss (10% increase in voltage, 30% to 50% increase in iron loss), excessive ambient temperature, and poor ventilation .
(6) The transformer caught fire from an external fire source. The combustibles accumulated around the transformer caught fire in the transformer and the transformer room, and the transformer caught fire.
