The Siemens 5SV3747-4 is a SENTRON residual current operated circuit breaker (RCCB) — 4-pole, Type B, short-time delayed, rated 80 A with a 500 mA residual operating current at 400 V AC. Type B detection handles AC, pulsating DC, and smooth DC fault currents up to 500 mA, which is what you need on VFD-fed circuits, UPS outputs, or PV inverters where plain AC/ A types would miss a DC residual. The short-time delayed design (SIGRES function) means it rides through transient earth faults without nuisance tripping — useful on feeders with surge arrestors or capacitive loads that generate brief leakage spikes.
Rated short-circuit current is 10 kA per IEC 61008-1, with a series fuse maximum permissible of 100 A — so it interrupts a fault up to 10 kA, and the upstream fuse (max 100 A) protects the device under higher prospective faults. The 0.8 kA rated conditional short-circuit current (IEC 61008-1) applies when the RCCB is backed by a 100 A gG fuse; that's the coordination figure the panel designer needs for selectivity. Supply voltage range is 70–440 V AC at 50/60 Hz, and the test circuit minimum is 70 V — so it remains functional down to that voltage for periodic self-testing.
Width is 72 mm (4 modular width units at 18 mm each), depth 70 mm, height 90 mm. Grid spacing is 60 mm — standard for DIN-rail enclosures. Installation depth is 70 mm, matching the depth dimension. Supplementary devices can be installed on the same rail.