The Siemens SENTRON 5SV4442-0 is a 4-pole residual current operated circuit breaker (RCCB), Type AC, rated 25 A with a 100 mA trip sensitivity at 400 V AC. It snaps onto a DIN rail (REG) and occupies 4 modular width units (72 mm wide), fitting standard 60 mm grid distribution boards. The IP20 rating applies when installed in a distribution board with conductors connected — normal for enclosed panel use, not for exposed outdoor mounting.
What the ratings mean for fit
The 100 mA sensitivity (Type AC) means this RCCB detects sinusoidal AC residual currents only — it will not trip on pulsed DC or smooth DC faults. That makes it suitable for circuits without rectified loads, VFDs, or UPS systems where DC leakage is present. For mixed loads, a Type A or Type B RCCB would be needed. The 25 A rating and 400 V AC supply voltage (230/400 V range) suit it for three-phase sub-distribution or feeder circuits in commercial or light industrial panels. The short-circuit current rating (SCCR) is 10 kA per IEC 61008-1, with a maximum permissible series fuse of 80 A. This means the RCCB can safely interrupt fault currents up to 10 kA, but it relies on an upstream overcurrent device (MCB or fuse) rated at 80 A max to provide backup protection. In a panel, coordinate the upstream breaker to ensure the SCCR of the assembly is met. Rated for overvoltage category III, it is designed for fixed installation in the distribution board, not for plug-in or portable use. The mechanical service life is 10,000 operating cycles typical — adequate for normal switching duty, not for frequent manual operation as a switch.
Mounting and integration
Snap-on DIN rail (REG) mounting, any position. Depth is 70 mm, matching the standard installation depth for SENTRON modular devices. The 72 mm width (4 MW) means it occupies four 18 mm slots on the rail. Supply can be connected from top or bottom. Supplementary devices (like auxiliary switches or shunt trips) can be installed on the side — check the product extension options for compatibility.