WHY PUT PEBBLES UNDER THE TRANSFORMER? WHAT IS THE REASON?

Oil-immersed transformers use oil as the main insulating means of the transformer and rely on oil as the cooling medium (self-cooling, air-cooling, water-cooling). The main reasons for placing pebbles in the oil pit of the oil-immersed transformer are: fire prevention and oil drainage.

This part under the oil-immersed transformer is usually called the oil unloading pool or the oil unloading, which leads to the accident oil pit or the accident oil pool. In the event of an accident, such as oil injection or explosion, the oil of the transformer will flow into the oil discharge pit through the cobblestone, and then flow to the accident oil pool. At this time, the cobblestone under the transformer plays an isolation role, reducing the fire and helping to extinguish the fire; in addition, the high temperature transformer After the oil is cooled by the pebbles, the fire can be reduced.

Some of the pools are made of grilles, and some are not. For grids, pebbles are placed on the grid; for those without grids, pebbles are placed in the oil discharge pit. Placing pebbles for easy oil unloading is one reason, and insulation for easy maintenance, inspection by operators, and work is also a reason.

When the transformer catches fire, the oil will still burn when it leaks to the ground, and it will not block the oil drain hole at the bottom of the oil drain pit. The oil flows to the bottom between the cobblestones of the transformer, and the surface avoids oil pollution. When the oil is drained, it also acts as a cooling oil temperature to prevent the oil from burning.