What this RCBO is and what the ratings mean
The Siemens 5SU1353-6KV10 is a combined residual-current circuit breaker with overcurrent protection (RCBO) — an FI/LS protector in the 5SU series. It packs a Type A residual-current device (30 mA IΔn) and a B-curve 10 A miniature circuit breaker into a single 1+N-pole module, rated for 4.5 kA breaking capacity. The Type A classification means it detects pulsating DC fault currents as well as sinusoidal AC — essential on circuits feeding single-phase electronics, switching power supplies, or variable-speed drives that can generate smooth DC residual currents a standard Type AC RCD would miss. The 30 mA trip threshold is the standard for personal protection against direct contact in residential and commercial final circuits. The B-curve 10 A overcurrent characteristic trips between 3 and 5 times rated current (30–50 A), sized for lighting, socket outlets, and general-purpose loads where inrush is moderate.
Panel integration and deployment
The 70 mm depth (D=70MM) is the dimension from the DIN-rail mounting plane to the front of the device — standard for Siemens 5SU-series RCBOs. It snaps onto a 35 mm DIN rail in the distribution board, occupying a single 1+N-pole modular width. The Type A RCD function makes it suitable for final circuits in commercial or residential panels where electronic loads are present; the 4.5 kA breaking capacity covers the prospective short-circuit current at the point of use in most domestic and light commercial installations per IEC 61009-1.