Device. Reduce damage that prevents magnification age to equipment. minimizes damage to other systems,and improves the safety of power systems, including power failure prevention. Types of protection relays include
current relayes, power relays direction relays,and differential relays. In addition, overcurrent(OCR), undervoltage(UVR), SELECTIVE GROUND RELAY(SGR), OVERVOLTAGE ground relay(OVGR), OVER current ground relay(OCGR), motor protection relay(MPR)3E RELAY,
Buch Holtz relay in case re-entry after breaking the line breaker by protection relay incase of transmission line accid of artificial etc, it is a device that automatically requests breaker.