The Siemens SENTRON 5SU9356-1CR40 is an RCBO — a residual current circuit breaker with integral overcurrent protection — rated 40 A with a 30 mA Type AC residual trip, C-curve characteristic, in a 1P+N (2-pole) form factor. It's designed for 230/240 V AC single-phase circuits at 50/60 Hz. Breaking capacity is rated 6 kA per EN 60898 and 10 kA per IEC 60947-2, giving the integrator headroom for fault-current coordination in residential or light commercial distribution boards. The C-curve trips between 5 and 10 times rated current — standard for motor-starter and lighting circuits with moderate inrush. The 30 mA residual sensitivity covers basic personnel protection against direct contact.
Mounting and Panel Fit
Occupies 2 modular width units (36 mm) on a DIN rail, with an installation depth of 70 mm and overall depth of 77 mm. Mounting position is any, which simplifies panel layout. IP20 rating applies when installed in a distribution board with conductors connected — standard for enclosed gear. Supply can enter from either top or bottom; the design is instantaneous (non-time-delayed) Type AC, meaning it trips on sinusoidal AC residual currents without intentional delay.
Environmental and Compliance
Rated for ambient temperatures from -40 °C to +75 °C, with max 95% humidity. Halogen-free and silicon-free construction. Overvoltage category III, pollution degree 2, surge voltage resistance 4 000 V. Mechanical life is 10 000 operating cycles typical.