The Siemens SENTRON 3VA9113-0RL20 is a load-side mounted residual current protection module — an RCD520 Basic, type A — designed as an accessory for the 3VA1 molded-case switch family. Type A detection means it catches both pure AC residual currents and pulsed DC up to 6 mA smooth — the standard for single-phase rectified loads like VFDs, switching power supplies, and LED drivers. The response value is field-selectable across seven steps: 0.03, 0.05, 0.1, 0.3, 0.5, 1, 3, and 5 A. That range lets you dial in the trip threshold to match the installation's leakage baseline — critical on long cable runs or dirty loads where a fixed 30 mA unit would nuisance-trip. The non-tripping time is also adjustable: 0, 0.06, 0.15, 0.3, 0.5, 1.0, 2.0, or 3.0 seconds. A delayed trip (tv > 0) provides selectivity with upstream RCDs — the fault clears at the closest device first, keeping the rest of the panel live. Set to 0 for instantaneous operation.
This module is a bolt-on accessory for the 3VA1 breaker family — it mounts on the load side via busbar connection. The infeed can come from the top or bottom, which simplifies busbar routing in a crowded panel. Screw fixing secures it to the mounting plate or DIN rail adapter. The 76.2 mm width is a standard 4-module (4 TE) footprint on a 35 mm DIN rail — it occupies four 18 mm slots. Power dissipation maxes out at 6.1 W, so thermal buildup in a sealed panel is manageable but worth checking if the enclosure is densely packed.