What is Oil Surge Relay in Transformer?


The protective Oil Surge Relay (OSR) is used to protect the malfunction developed inside the On Load Tap Changer (OLTC).

 This protective relay triggers the tripping circuit when the oil flow exceeds the specified limits, thus making the transformer to be turned off and contain the damager to the OLTC and Transformer.

OSR is used to report any malfunction developed inside the On Load Tap Changer Chamber.

OSR is Oil actuated Relay.

OSR is installed in the pipe between OLTC head and the oil conservator.

OSR relay is actuated when the flow rate of oil exceeds the preset value.

OSR detects excessive oil surge after any fault occurs inside OLTC Chamber.

OIL SURGE RELAY is basically an Oil surge actuated relay, installed in between OLTC(on-load tap changer) and OLTC conservator tank. 

It is basically to save the Transformer from getting damaged due to any fault in the OLTC chamber.

Oil surge happens due to Excessive increase in Oil Volume inside Oltc tank during Switching or any kind of fault inside OLTC. 

During fault value of current inside OLTC increases and thus in square proportion the heat increases, which cause in Oil Surge to flow from OLTC to OLTC conservator tank Via OSR, and trip command by NO/NC contact of the relay to circuit Breaker Trip coil to stop feeding the Transformer in faulty condition.

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