What it is
This is a Siemens 5SU1654-7KV32 FI/LS protector — a combined RCD/MCB in one 1+N-pole module. It packs both overcurrent and residual current protection into a single 70 mm wide unit, saving a DIN-rail slot over separate devices.
Protection profile
Type A detects pulsating DC and AC sinusoidal residual currents. The 300 mA trip threshold suits sub-distribution circuits. The thermal-magnetic overcurrent side is C-curve, rated 32 A. That means a magnetic trip between 5× and 10× In — 160 A to 320 A — sized for motor, lighting, or mixed loads with moderate inrush. Breaking capacity of 10 kA per IEC 60898-1 covers most commercial and light industrial panel fault levels.
Panel fit
Snaps onto standard 35 mm DIN rail. At 70 mm wide (4 module spaces), it replaces a separate RCBO or an RCD + MCB pair at the same footprint. The 1+N-pole format switches the line and monitors the neutral — no neutral bar needed downstream for the RCD function.