Transformer overload requirements
It is normal for transformers to be overloaded. After all, if an accident occurs, ensuring uninterrupted power supply is the most important thing to consider, and insulation aging should be put aside. However, transformers cannot always be overloaded. There are still requirements:
1. Allowable overload
Transformer allowable overload means that the overload degree is not large, and the load before overload is light, the transformer oil temperature is not high, and the hot spot temperature of the winding will not reach a harmful level.
2. Limit overload
The transformer is overloaded to a large extent, which increases the oil temperature. The hot spot temperature of the winding may reach a harmful level, but it has not yet reached a dangerous level. At this time, although the transformer can continue to operate, it will reduce the insulation strength, threaten the safety of the transformer, and affect the life of the transformer. This overload must be limited.
3. Prohibit overload
The transformer is overloaded to a large extent and for a long time, so that the oil temperature has exceeded the allowable value, and the hot spot temperature of the winding has reached a dangerous level. If it continues to operate, the insulating oil around the hot spot will decompose and produce bubbles, and the insulation strength will seriously decrease. This overload must be prohibited.
