PT disconnection, a relatively common fault in electrical power production, occurs when the voltage transformer loses connection. While this is bad, It's not a complete disaster. Once the PT is disconnected and loses voltage, it critically affects the accuracy and reliability of protection, metering, and measurement operations. What controls it: Relay performance depends on the protected zone, CT/PT inputs, pickup settings, time delay, breaker clearing time, trip. New industry Technology regarding to Bussmann fuse, ABB breakers, Amphenol connectors, HPS transformers, etc. Its primary functions include: Switching Operations: Switchgear allows operators to control the.