RCBO for final-circuit protection
The Siemens 5SU1653-7KK32 is a SENTRON RCBO combining overcurrent and residual-current protection in a single 36 mm wide, 2-module unit. The Type A fault-current detection handles pulsating DC and AC residual currents, covering most commercial and industrial socket-outlet circuits. The 1P+N configuration switches the phase only; the neutral is switched internally but not protected against overcurrent — typical for single-phase final circuits in TN or TT systems.
The 32 A rating is derated across ambient temperature: 30.4 A at 40 °C, 28.8 A at 50 °C, down to 24.64 A at 70 °C. The solid and stranded conductor range of 0.75 to 35 mm² covers everything from 1.5 mm² lighting circuits up to 10 mm² feeder tails; no adapter needed for the larger cross-sections. Energy limiting class 3 means it lets through less let-through energy (I²t) than class 2 or 1 devices, which helps with downstream coordination. The instantaneous design (no intentional time delay) trips within the standard C-curve window of 5× to 10× In — so 160 A to 320 A fault current clears in under 0.1 s.
Depth is 77 mm (installation depth 70 mm), height 90 mm — fits most distribution boards without depth clearance issues. IP20 with the distribution board installed and conductors connected; not rated for wet or dusty environments without an enclosure.