The Siemens 5SU9346-7CN20 is a SENTRON RCBO (RCD-operated circuit breaker) combining overcurrent and residual current protection in a single 4-pole module. Rated 20 A with a C-tripping characteristic and 30 mA Type A sensitivity, it handles mixed resistive-inductive loads and pulsating DC fault currents common in modern electronics. The 6 kA breaking capacity per EN 60898 covers most domestic and light commercial panels; the 10 kA rating per IEC 60947-2 gives headroom for industrial distribution boards where fault levels run higher.
Occupies 2 modular width units (36 mm) on a DIN rail. Depth of 77 mm and installation depth of 70 mm fit standard distribution boards; the 126 mm width and 90 mm height are within the envelope of a typical 4-pole RCBO. IP20 rating applies when installed in a distribution board with connected conductors — not a standalone enclosure rating. Mounting position is unrestricted. Supply can enter from top or bottom, which simplifies panel layout.
Rated insulation voltage 440 V, overvoltage category III, pollution degree 2 — suitable for fixed-installation mains circuits. Surge voltage resistance 4 kV, surge current resistance 1 kA (8/20 μs). Mechanical service life 10,000 operating cycles typical. Power dissipation per pole 0.75 W at rated current in hot state, useful for thermal derating calculations in dense panels. Halogen-free and silicon-free construction.