VigiPacT RH99M is a DIN rail mounting residual current monitoring relay. It monitor drops in electrical insulation due to ageing of cables or extensions in the installation. It measures the earth leakage current in an electrical installation via its associated toroid. A control signal is issued by the relay when the residual-current operating threshold is overrun. The operational supply voltage is 12/24VAC 50/60Hz, or 12/48VDC. 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. There is an automatic 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 type A toroid or rectangular sensor.