Using a 300 mA RCD for fire protection at the main distribution points and a 30 mA RCD for life protection at secondary distribution points, along with thermal-magnetic circuit breakers or automatic fuses (separately or together), ensures selectivity between all protection. Using a 300 mA RCD for fire protection at the main distribution points and a 30 mA RCD for life protection at secondary distribution points, along with thermal-magnetic circuit breakers or automatic fuses (separately or together), ensures selectivity between all protection. An accurate protection of people and electrical equipment against leakage currents can be achieved by installing Residual Current Devices (RCDs) which detect an imbalance of the electrical flow and trip assuring indeed protection against earth fault, reducing the risk of death or serious injury and. Safely disconnect the power in the event of a fault with residual current devices (RCDs) — essential in building electrical distribution boards. Here you will learn how to connect RCDs, what to do if the fuse blows, and what types of RCDs are available. What does an RCD do? Also known as a ground. SENTRON RCDs offer the right solution for any application, immediately cutting power during a fault to protect against dangerous shock currents. Contact us for sales and pricing information. The primary function of an RCD is to monitor the electrical current. Protection devices include miniature circuit breakers (MCB), residual current devices (RCD), residual current circuit breakers (RCCB), residual current breakers with overcurrent protection (RCBO) & surge protection devices (SPD). The offer also includes a suite of power metering, control and.