Issues regarding transformer gas protection
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Explanation of Article 4.3.6 of the Civil Code: Oil-immersed transformers with a capacity of 800 kVA or more must be equipped with gas protection, but the power supply side of the transformer is often not located near the transformer itself, making it difficult to implement gas protection. What I don’t understand is: isn’t gas protection installed on the transformer? What does it have to do with where the power source is located? Thank you all
Gas protection is a type of protection for the transformer itself; it involves non-electrical alarm and tripping signals. Once the gas relay activates in alarm or tripping mode, it sends a signal to the remote high-voltage cabinet to trigger an alarm or to cut off the power supply on the high-voltage side.
It refers to the circuit breaker for the transformer power supply; for example, in residential transformers, the control switch is not located near the transformer, and hard wiring results in a long distance between them
Actually, the power source is quite far away; we can use a gas relay connected to the low-voltage main supply, so that the load will be cut off when the gas activates.
Gas protection requires cutting off the power supply side; what’s the use of cutting off low-voltage loads?
Here’s how it works: Gas protection involves connecting the on/off signal from the gas relay installed on the transformer itself to the integrated protection system located in the transformer’s high-voltage output cabinet, so that the integrated protection system can be used to protect the transformer. Generally, it triggers a low gas alarm, while a high gas level causes an interrupt. The alarm and trip action signals usually need to be transmitted to the signal panel to alert the duty personnel.
There’s no gas protection below 800, right?
Thank you. Can’t a incoming circuit breaker be installed at the location of the transformer? Wouldn’t that solve the problem? Does it mean we need to add another high-voltage cabinet, which increases costs?
The distance between the transformer and the high-voltage switch is not great, and they are under the same management; there is no need to install a high-voltage cabinet on the local side of the transformer, as this would unnecessarily create additional failure points. However, some people prefer to include such a cabinet