Newly installed or overhauled transformers will take air into the transformer's oil tank with little attention during refueling and oil filtering. If the air is not discharged in time before commissioning, after the transformer is commissioned, due to the rise in oil temperature, the oil in the oil tank will form a convection, and the air will "drive" out of the oil surface, so that the gas relay will operate. Generally, the more gas there is inside, the more frequently the gas breaker operates.
In the early stage of commissioning, if it is found that the gas relay operates frequently, a comprehensive analysis should be conducted based on the sound, temperature, oil level of the transformer, and the conditions of refueling and filtering oil. If the transformer is operating normally, it can be determined that it is caused by the air. Otherwise, gas should be used for ignition test to determine whether the transformer itself is faulty and the nature of the fault, so that appropriate measures should be taken to eliminate it in time to avoid fault expansion and ensure safe operation of the transformer.