5SM2121-0 SIEMENS

The 5SM2121-0 is a 2-pole residual current (RC) unit manufactured by Siemens, designed for use with 5SY series miniature circuit breakers (MCBs). This RC unit provides enhanced protection against electrical hazards by detecting residual currents, which indicate potential insulation faults or leakage currents. It is specifically designed for AC type residual currents, ensuring reliable operation in standard alternating current electrical systems. The unit has a rated current (In) of 16A, making it suitable for circuits with moderate current demands. With a tripping current of 10mA, it offers a high degree of sensitivity, quickly disconnecting the circuit in the event of a fault to prevent electric shock. The rated voltage (Un) is 230V AC, compatible with typical household and commercial power supplies. This RC unit is essential for ensuring safety in electrical installations, protecting against both direct and indirect contact with live parts. Its compact design allows for easy integration with existing Siemens circuit breaker systems. By adding this RC unit, electrical systems gain an additional layer of protection, minimizing the risk of electrical accidents and equipment damage. It adheres to industry standards for safety and performance, providing peace of mind for users and installers alike.