What this RCBO is and what it protects
The Siemens 5SU9356-1CN10 is a 1P+N residual-current-operated circuit breaker (RCBO) from the SENTRON family, combining overcurrent and earth-fault protection in a single 2-module-wide unit. It is rated 10 A with a 30 mA residual-current trip, Type AC (sensitive to sinusoidal AC fault currents), and a C tripping characteristic — meaning it tolerates short inrush peaks typical of motor or capacitive loads before the thermal-magnetic mechanism clears a sustained overload or short circuit. Breaking capacity is 6 kA per both EN 60898 (the household-standard) and IEC 60947-2 (the industrial-standard), so it is rated for the same fault level regardless of which code governs the panel. The operating voltage is 230/240 V AC, 50/60 Hz, with an insulation voltage (Ui) of 264 V and a rated surge voltage resistance of 4 000 V — overvoltage category III, pollution degree 2, which covers fixed-installation distribution boards in buildings and light industrial environments.
Mounting and integration into a panel
The 5SU9356-1CN10 occupies 2 modular width units (36 mm) on a standard DIN rail. Depth is 77 mm, installation depth 70 mm, height 90 mm. Mounting position is any — no derating for horizontal or inverted orientation. The supply cord can enter from either top or bottom, which simplifies busbar routing in a crowded enclosure. IP20 is achieved only when the distribution board is installed and conductors are connected — so the device itself is finger-safe but not sealed against dust ingress until panel-closed.
What the ratings mean for the buyer's decision
The 30 mA residual sensitivity (Type AC) is the standard for general-purpose socket-outlet protection in residential and commercial final circuits per IEC 60364. It detects sinusoidal AC earth faults only — not pulsating DC or smooth DC faults. If the downstream load includes rectifiers, variable-speed drives, or LED drivers that can generate DC fault components, a Type A or Type F RCBO would be needed instead. The C characteristic (10× to 15× In magnetic trip) means it will not nuisance-trip on the inrush of a small motor or a bank of capacitors, but it will still clear a hard short within the 6 kA rating. Mechanical service life is 10 000 operating cycles typical — adequate for a final-circuit breaker that sees occasional manual switching, not a contactor duty cycle. Power dissipation per pole at rated current in hot operating state is 0.75 W, so two poles total 1.5 W heat inside the enclosure — negligible for thermal budgeting in a standard distribution board.