油浸式变压器总是存在着发生火灾的危险。由于短路、操作过电压、雷电过电压、过负荷等情况下变压器产生的电弧能量使油温超过燃点，并分解出多种可燃气体，使变压器内部压力骤增。
The danger of fire always exists in oil immersed transformer. Due to the arc energy generated by the transformer under the conditions of short circuit, operation over-voltage, lightning over-voltage and overload, the oil temperature exceeds the ignition point, and a variety of combustible gases are decomposed, which makes the internal pressure of the transformer surge.
一旦内部超压，会使得顶部套管或本体油箱泄漏、爆炸而导致氧气进人，或大量燃烧的油可能大面积流出，从而引起火灾，造成重大危害。为及时扑救油浸式变压器引发的火灾，按照有关消防规定和设计规程，国内220kV及以上变电站（升压站）主变压器（以下简称主变）都装设了灭火设施，主要采用了充氮灭火装置。
Once the internal overpressure occurs, it will cause the leakage and explosion of the top casing or the main oil tank, which will lead to the oxygen entering into people, or a large amount of burning oil may flow out in a large area, thus causing a fire and causing significant harm. In order to put out the fire caused by the oil immersed transformer in time, according to the relevant fire-fighting regulations and design regulations, the main transformers (hereinafter referred to as the main transformers) of domestic 220kV and above substations (booster stations) are equipped with fire-fighting facilities, mainly nitrogen filled fire-extinguishing devices.