Type B RCCB for mixed-frequency residual currents
The Siemens SENTRON 5SV3624-4 is a 2-pole residual current operated circuit breaker (RCCB) rated 40 A with a 300 mA trip threshold, designed for 230 V AC systems. Its Type B characteristic detects smooth DC residual currents and mixed-frequency AC/DC faults — the kind generated by variable-frequency drives, UPS systems, and power supplies that a standard Type A cannot see. The short-time delayed design (SIGRES function) prevents nuisance tripping from transient surge currents or inrush from connected electronics, making it a fit for mixed-load sub-distribution boards where both sinusoidal and pulsed DC leakage are present. Rated short-circuit capacity sits at 10 kA per IEC 61008-1, with a maximum permissible series fuse of 100 A upstream for fault backup. The unit occupies 4 modular width units (72 mm) on a DIN rail (REG) and can be mounted in any position — no derating required for horizontal or inverted orientation. Power loss per pole at rated current in hot operating state is 2.5 W, which matters when calculating thermal load in a crowded enclosure.
Integration into the sub-distribution board
Snap-on DIN rail (REG) mounting, 72 mm wide (4 MW), 70 mm installation depth. Supply can enter from top or bottom; for the SIGRES function the supply remains live at the top terminal even when the device is switched off. IP20 rating applies only when the distribution board is installed with connected conductors — treat it as a panel-internal device, not for exposed mounting. Silicon-free construction suits environments where outgassing could affect contacts or electronics. Supplementary devices (auxiliary switches, shunt trips, undervoltage releases) can be installed on the right side via the product extension interface. Operating frequency is 50/60 Hz; supply voltage for the test circuit is 70–250 V AC. Mechanical service life is 10 000 operating cycles typical — adequate for distribution protection but not for frequent switching duty.