The Siemens 3VM9114-0RS10 is a SENTRON RCD110 residual current device (RCD) module — a Type A side-mounted accessory for 3VM molded-case circuit breakers. It adds ground-fault protection to the breaker without needing a separate enclosure. Rated for 160 A at 50/60 Hz, it handles the full load current of the upstream breaker and lets you dial in the trip threshold from 0.03 A up to 5 A, covering everything from personnel protection (30 mA) to equipment-level fault detection (5 A). Type A RCD means it detects both sinusoidal AC residual currents and pulsating DC residual currents — the kind you get from rectified loads like VFDs, switching power supplies, and UPS systems. That makes it a better fit for modern panels than a basic AC-only RCD.
This module is designed to side-mount onto a 3VM breaker frame. It uses screw fixing and the electrical connection is made through the breaker's own cable connection — no extra wiring terminals on the RCD itself. The infeed can be from top or bottom, which helps with busbar routing in tight panels. Physical footprint: 70 mm deep, 131.8 mm wide, 187 mm tall. That depth is worth noting — at 70 mm it sticks out less than some standalone RCDs, but you still need to account for it when sizing the enclosure depth.