RCD-operated circuit breaker, 10 A, 10 mA — what the ratings mean
The Siemens SENTRON 5SU9156-7VK10 is a 2-pole RCBO combining overcurrent protection (Class C trip characteristic, 10 A rated) with residual current detection (10 mA, Type A) in a single 36 mm wide module — two modular width units on the DIN rail. The 10 mA trip threshold catches leakage paths that a standard 30 mA RCD would miss, which makes it the right choice for circuits supplying wet-area equipment or medical IT rooms where lower leakage tolerance is specified. Type A detection covers pulsating DC residual currents from half-wave rectified loads (typical in switching power supplies and variable-speed drives), so it handles the modern load mix better than a Type AC device.
The 10 A rating at 30 °C drops to 9.4 A at 40 °C, 9.1 A at 45 °C, 8.7 A at 50 °C, and 8.1 A at 55 °C.
Panel integration — footprint and clearance
Width is 36 mm (2 MW), depth 77 mm, height 90 mm, with an installation depth of 70 mm. The IP20 rating applies only when the distribution board is installed and conductors are connected — so during panel assembly before the cover is on, treat it as a touch-protected device, not sealed. Power supply cord can enter from either top or bottom, and the touch-protection feature is built in (no separate finger duct needed). Halogen-free and silicon-free construction keeps it compliant for clean-room or sensitive-environment panels where outgassing matters.