What are the causes of spontaneous combustion of power transformers

I. There is no commercial insurance on both sides of high and bottom voltage of distribution transformer. Although some have already installed drop type fuse and shofar commercial insurance, but its fuse is mostly aluminum or copper wire replacement, resulting in the bottom voltage short circuit fault or load, fuse can not all normal melt and burn the transformer. The high and low fuses of distribution transformers are not well equipped. The fuse on the transformer is generally equipped with too much, which leads to the burning of the transformer when the distribution transformer is heavily loaded.

2. Because there are many rural lighting routes, most of them also use single-phase power supply system. In addition, the blindness of leakage line in the construction site and the untimely management method lead to the phase-biased operation of the distribution load. Long-term application, resulting in a phase of electromagnetic coil insulation layer embrittleness and burned transformer.

Three, tap the power switch.

1. Adjust the tap power switch without authorization. Because the difference between the electricity load in the two seasons of the year is large, the height of the working voltage is large. Therefore, some rural and company welders did not adjust the tap power switch without the experimental adjustment of the power engineering repair and test unit, resulting in the variation of the tap power switch is not timely, loose and burned.

2, the tap power switch quality is poor, the structure is not scientific, the working pressure is insufficient, the touch is not reliable, the external word wheel part and the internal specific part are not completely consistent, resulting in the star type dynamic circuit breaker part does not touch, the displacement of the dynamic and static contacts make the insulation layer between the two taps narrow, and in the two taps in the middle of the potential difference effect of short circuit fault or charge and discharge to the ground, Short circuit capacity will quickly burn the tap wire turn, and even cause the destruction of all winding resistance.

Fourth, oil leakage is a more common surface anomaly of transformers. Because the transformer body is filled with oil, the connection position often glue beads, leather pads to avoid oil leakage. After long-term operation, some rubber beads and leather pads in the transformer will be embrittled and cracked, resulting in oil leakage, which may lead to the reduction of the characteristics of the insulation layer after moisture return, charge and discharge short circuit fault, and burn the transformer.

Five, the distribution transformer high and bottom voltage route is mostly imported by the transmission line, because the zinc oxide arrestor is not immediately put into use or no 10kV zinc oxide arrestor is installed, resulting in the burning of the transformer when struck by lightning.

Six, some distribution transformers are not equipped with a level of maintenance, or equipped with a level of maintenance but its action, credibility is low.