What this RCBO is and what the ratings mean for fit
The Siemens 5SU1324-7KX32 is a 2-pole RCBO from the SENTRON family — a combined overcurrent and residual-current device in one modular unit, rated 32 A at 30 °C with a 30 mA Type A residual-current trip and C characteristic. The C curve means the magnetic trip operates at 5 to 10 times rated current, so it handles motor inrush and transformer energisation without nuisance tripping on a standard distribution board. The 10 kA breaking capacity per EN 60898 tells you it safely interrupts a short-circuit fault up to that level at the rated voltage — enough for most commercial and light industrial sub-distribution boards. Type A residual detection covers pulsating DC fault currents from electronics and rectifier loads, which the older AC-only types miss. Derating matters here: the 32 A rating holds at 30 °C, but drops to 30.4 A at 40 °C and to 24.64 A at 70 °C. If your panel ambient runs above 40 °C, size the load for the lower figure — the thermal element is what governs continuous current in a C-curve RCBO.
Panel fit and mounting
Occupies 3 modular width units (54 mm) on a DIN rail. Depth is 77 mm, installation depth 70 mm — verify your enclosure depth clears the wiring space behind the unit. Mounting position is any, so vertical or horizontal rail orientation works. Supply can enter from top or bottom, which simplifies busbar routing in a crowded board. IP20 with conductors connected — standard for enclosed distribution boards, not for wet-area standalone use.
Compliance and approvals
Rated per EN 60898 for breaking capacity, overvoltage category III, pollution degree 2. Halogen-free and silicon-free construction — relevant for clean-room or sensitive-environment installations where outgassing contaminates optics or contacts. Energy limitation class 3 means the let-through energy is low enough to protect downstream equipment in a fault.