The Siemens SENTRON 3VA9213-0RL20 is a load-side mounted residual current device (RCD520 Basic) designed as an accessory for the 3VA1 molded-case circuit breaker family. It's a type A RCD — catches pulsating DC fault currents on top of standard AC sine-wave leakage, which is what you need on VFD-fed motor circuits or any load with half-wave rectification.
Rated at 250 A continuous (In) and 100–480 V AC, so it sits downstream of a 3VA1 breaker sized for that current class. The adjustable residual current response spans 0.03 A to 5 A in discrete steps — you dial in the trip threshold to match the branch's leakage profile without nuisance tripping. The non-tripping time (tv) is adjustable from 0 to 3000 ms, giving you selectivity coordination with upstream RCDs: set a longer delay on this module so a downstream fault clears first. Three-pole construction, so it's for three-phase circuits without a neutral conductor (or where neutral protection is handled separately). The infeed can land on either top or bottom terminals — no forced orientation, which simplifies busbar routing in a crowded panel. Power loss is 21 W maximum — that's the heat this module dumps into the enclosure.
Integration note
Mounts via screw fixing to the 3VA1 breaker's load side — no DIN rail required, it bolts directly to the breaker's busbar connection. Dimensions are 105 mm wide × 115 mm high × 70 mm deep, so it adds about 70 mm of depth behind the breaker face. Sealable cover is standard (for lockout/tagout or panel-security requirements). The module includes a pre-alarm indication at 30% of the set residual current — gives you a heads-up before the trip threshold is reached, useful for predictive maintenance on circuits with slowly degrading insulation.