The purpose of Earth Leakage protection is to measure the Earth leakage current of an electrical installation, or part of an installation, and interrupt the power supply if the Earth-Leakage current becomes dangerous to property.

RISH Relay V/Hz is used to protect against Over Voltage, Under Voltage, Phase Unbalance, Phase Sequence detection, Phase Failure
detection, Under and Over Frequency conditions.
RISH Relay I is used to protect against Over Current, Under Current, Current Loss, Current Un balance.