1SYF274027R1254

The ABB DSB204M AC-C25/30mA, part number 1SYF274027R1254, is a four-pole residual current circuit breaker with overcurrent protection (RCBO), designed to protect compatible low-voltage electrical installations against overloads, short circuits and earth-leakage faults.

The device has a rated current of 25 A, a C-type tripping characteristic and a rated residual operating current of 30 mA (0.03 A). Its Type AC residual-current detection is designed to respond to sinusoidal alternating residual currents. The four-pole configuration is intended for compatible three-phase electrical systems, including neutral switching, and the six-module design supports DIN-rail mounting in distribution boards and electrical control panels.

This RCBO combines overcurrent protection and residual-current detection in one device. Its 30 mA sensitivity provides additional protection against electric shock when correctly selected and installed. Suitability depends on the load, cable capacity, system configuration and prospective short-circuit current. Installation should follow ABB's technical documentation and applicable electrical standards.