RH99M is a DIN rail mounting residual current protection relay. It protects against people direct or indirect contact, property fire hazards and motors. It measures the earth leakage current in an electrical installation via its associated toroid. It trips the associated circuit breaker when the set residual operation current is overrun. The operational supply voltage is from 220 VAC to 240 VAC 50/60Hz. The current sensitivity is selectable with 9 thresholds from 30 mA to 30 A. The time delay is selectable with 9 settings from instantaneous to 4.5s. It requires a local manual reset after a fault clearance. The monitored distribution system voltage is up to 1000 VAC 50/60/400 Hz. It is installed on a DIN-rail inside a switchboard and the protection degree is IP40. It must be associated with a compatible Schneider Electric toroid.