1SYF272027R3404

The ABB DSB202M AC-C40/300mA, part number 1SYF272027R3404, is a two-pole residual current circuit breaker with overcurrent protection (RCBO) designed to protect compatible low-voltage electrical circuits against overloads, short circuits and earth-leakage faults.

The device has a rated current of 40 A, a C-type tripping characteristic and a rated residual operating current of 300 mA (0.3 A). Its Type AC residual-current detection responds to sinusoidal alternating residual currents. The two-pole configuration is intended for compatible single-phase electrical circuits, and the four-module design supports DIN-rail mounting in electrical distribution boards and control panels.

The RCBO combines overcurrent protection and residual-current detection in one unit. It is suitable for residential, commercial and industrial electrical distribution applications where the current rating, leakage sensitivity and breaking capacity meet the installation requirements. The 300 mA sensitivity is generally used for installation or equipment protection and does not replace 30 mA additional protection against electric shock where required. Installation should follow ABB's technical documentation and applicable electrical standards.