Siemens 5SX21-C3 Mini Circuit Breaker 1 Pole 230 400V

Siemens 5SX21-C3 is a single-pole miniature circuit breaker (MCB) rated for 230/400 V AC with a 3 A nominal current and a Type C tripping characteristic. The 5SX21-C3 designation identifies a 1-pole device in Siemens’ 5SX family of miniature circuit breakers, designed to interrupt current quickly when overloads or short circuits occur on a single branch circuit. This compact protective device is intended for use in compatible Siemens panels and electrical enclosures where small-current protection is required, such as lighting or small-appliance circuits in residential or light commercial installations. The Type C curve provides intermediate tripping behavior for loads with moderate inrush currents, translating to reliable protection for circuits that experience brief surges without nuisance trips. With a 230/400 V AC rating, the breaker is suitable for standard single-phase distribution on circuits that run at this voltage, ensuring conductors and connected devices are safeguarded from overcurrent events.