Introduction to the principle of gas relays
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A gas relay is a protective device used in oil-immersed transformers. When an internal fault in the transformer causes the oil to decompose and generate gases or leads to fluctuations in oil flow, it activates the relay’s contacts, connecting the designated control circuit and sending a signal in a timely manner or automatically shutting down the transformer. Typical operating temperature range: -30 degrees Celsius to 95 degrees Celsius. Contact rating: AC 220V 0.3A, DC 220V 0.3A
The gas relay is an important primary protection device for transformers, and it is installed in the oil pipe beneath the transformer’s oil conservator. Light gas is primarily manifested when, during operation or minor faults, gases generated by the decomposition of oil rise into the gas relay; these gases increase the pressure, causing the oil level to drop. As a result, the open cup in the relay drops along with the oil level, and the reed contacts connected to this mechanism are activated to send a signal. When there is an excess of gas, it can be released through the vent on the gas relay. Heavy gas is primarily manifested by the intense gas generated by severe internal faults in the transformer (especially faults such as inter-winding short circuits for which other transformer protection mechanisms cannot respond quickly). This gas pushes the oil flow, which in turn impacts the baffle; the magnet on the baffle attracts the reed contacts associated with heavy gas, causing the contacts to close and thus trigger a trip.