What this RCCB is and what the ratings mean
The Siemens SENTRON 5SV3344-6XX01 is a 4-pole residual current circuit breaker (RCCB) rated for 40 A continuous at 40 °C, with a 30 mA residual trip threshold and Type A sensitivity — meaning it detects sinusoidal AC fault currents plus pulsating DC fault currents, which covers most modern electronic loads like VFDs, switched-mode supplies, and single-phase rectifiers. The instantaneous design (no short-time delay) trips within the standard 300 ms window, making it suitable for direct fault protection in TN and TT systems. The 10 kA short-circuit current rating (SCCR) at 50 Hz means the device can safely interrupt a fault up to 10 kA without rupturing, provided the upstream overcurrent device is properly coordinated. Rated current holds flat at 40 A from 40 °C up to 70 °C — no derating needed in warm enclosures up to that point. The permissible let-through current is 5 200 A, and the I²t withstand is 58 000 A²·s, which gives the upstream MCB or fuse a defined energy window to clear without damaging the RCCB.
Mounting and panel integration
Snap-on DIN rail (REG) mounting, any orientation. Occupies 4 modular width units (72 mm wide, 90 mm tall, 70 mm deep). The depth matches standard 70 mm installation depth for flush-mount distribution boards. Supply can enter from top or bottom — no polarity restriction on the line/load side for an RCCB, but Siemens recommends line at top for consistency with other SENTRON devices. IP20 rating applies when installed in a distribution board with connected conductors — not for open-panel use without a cover. Silicon-free construction matters for automotive or coating-sensitive environments where silicone outgassing can cause contact or adhesion failures. Overvoltage category III means it is rated for fixed-installation distribution level, not for downstream socket outlets.