Power transformer operation such as the occurrence of localized heating, in many cases, did not perform as electrical anomalies, and first exhibited is abnormal oil and gas decomposition. Namely, the oil in local high temperature decomposition for gas gathering in the transformer cover at the upper end and the gas relay. The difference between gas production and gas production rate; the size, is actually the difference between the size of the overheating fault.

Ⅰ 、after the action of the light gas. Signal light gas action, first of all, we should stop the audio signal, and check the gas relay gas, to ascertain the reasons.
1, non fault. Such as: air intrusion transformer, filter oil; oil level is reduced to below the gas relay (float type gas relay) or level decreases sharply (flapper gas relay); gas protection secondary circuit fault (such as inlet gas relay junction box, terminal row or secondary cable short circuit). As for the external reasons to determine the cause of action, the recovery signal, the transformer can continue to run.
2, reasons, main transformer fault. If you are not sure is due to external reasons caused by gas signal action, and found no other abnormalities should be gas protection tripping circuit input, at the same time, strengthen the monitoring of transformer, carefully observe the development and changes.

Ⅱ、heavy gas protection action: after the operation of the transformer gas protection tripping signal, or the gas and gas trip at the same time, first consider the transformer internal fault may. Treatment of this kind of transformer should be very careful.
The gas generated in the transformer fault is due to the nature of transformer in different parts of ascertain gas relay gas, gas concentration, the speed and quantity degree is crucial. Due to different forms of overheating. Therefore, to determine the nature and extent of the transformer fault is crucial.

1, of agglomeration, and the gas is colored non smelly and nonflammable, gas action is caused by the oil separated from the air, then you can decide as belonging to the non fault, power transformer can continue to run.

2,  the gas is flammable, it is most likely due to the internal fault of transformer. For this type of transformer, without inspection and test before, are not allowed to put into operation.

Power transformer protection action of gas as a precursor of internal accident, or is itself an internal accident. Therefore, on this kind of transformer send, send, supervision of operation should be especially careful, the cause of the accident did not check Mingqian shall not send.