Under Voltage Protection Relay

Under voltage protection sense the phase to phase voltage of the generator transformer using instrument transformer potential transformer.

Under voltage protection relay.

A three phase monitor relay with undervoltage protection can shutdown equipment when undervoltage occurs preventing damage. The time setting is used to avoid tripping due to any transient disturbances. As long as the monitored voltage remains below the maximum voltage the equipment can withstand the relay remains de energized and remains closed keeping the load energized. Three phase motors and other equipment are commonly used in a variety of industries.

If the voltage falls below this level for the set amount of time then the tripping command issued by the relay and hence the system is isolated. This information is internally processed by the microprocessor to take the voltage protection. A clear indication of the fault present is provided by these relays for rapid troubleshooting and reduced downtime. The under voltage setting is usually 80 percent of the normal operating voltage.

Principle of under voltage protection. Current protection relay dgp excitation loss over voltage under voltage. When the voltage drops below the rated voltage typically 85 stage 2 90 stage 1 the under voltage protection will be activated. Geya under over voltage relay provides protection to equipment that cannot handle excess voltages.