Dry transformers are damp, cores are damp, coils are damp: e

Wiring diagram of transformer gas protection principle

 

The main component of transformer gas protection is gas relay, which is installed in the connecting pipe between the oil tank and the oil pillow. When the transformer has an internal fault, the gas gas generated by the expansion of oil and gas flow along the connecting pipe through the gas relay to the oil pillow. If the flow speed reaches a certain value, the baffle inside the gas relay will be impulsive and tilt to one side, so that the contact of the gas relay will be closed and the trip circuit will be connected or a signal will be sent out, as shown in Fig. 19: the upper contact of the gas relay KG is connected to the signal, which is light gas protection; The lower contact is heavy gas protection, and the intermediate relay KOM at the exit is started through the signal relay KS and connection plate XE. After the two pairs of contacts of KOM are closed, the circuit breaker QF1, QF2 and tripping coil are excited respectively. Jump the circuit breaker on both sides of the transformer, that is:

 

DC + → KG → KS → XE → KOM → DC -, start KOM.

 

DC + → KOM → QF1 → YT → DC -, jump circuit breaker QF1.

 

DC + → KOM → QF2 → YT → DC -, Jump circuit breaker QF2.

 

Moreover, the connecting piece XE can also be connected to the resistance R, so that the heavy gas protection will not throw trip and only send signal.