Rated for the heavy line — 125 A, 300 mA, Type AC
The Siemens 5SV4645-0 is a 4-pole residual current operated circuit breaker (RCCB), Type AC, rated 125 A continuous with a 300 mA trip sensitivity on a 400 V AC supply. That 300 mA threshold means it catches earth-leakage faults on equipment and distribution circuits, not personnel protection — the trip level is above the 30 mA required for direct contact. For a 125 A feeder, this is sized for a sub-distribution board feeding multiple loads, not a single final subcircuit. Type AC detection means it responds to sinusoidal AC residual currents only. If the downstream load includes rectifiers, VFDs, or switched-mode supplies that generate pulsed or smooth DC fault currents, a Type A or Type B RCCB would be needed instead. Verify the load profile before committing this to the BOM.
Active production — no LTB clock ticking
RoHS compliance is confirmed effective 02 June 2023. REACH candidate-list information is on file. Export control is AL: N / ECCN: EAR99 — no special licensing for most destinations.
Panel integration notes
Packaged as a single unit, dimensions 78 x 97 x 85 mm (L x W x H). Snaps onto DIN rail in the distribution board. The 4-pole (3P+N) format occupies four modular widths — plan for 72 mm at 18 mm per pole. Terminal capacity and torque settings follow Siemens standard for the 5SV series; consult the installation instructions for strip length and tightening spec.