The Siemens 3VA9323-0RL30 is a SENTRON RCD820 advanced residual current protection module, Type A, designed as a load-side mounted accessory for 3VA2 molded case circuit breakers. It carries a 400 A rated operational current at AC across 3 poles, with a selectable residual current response from 0.03 A up to 30 A and an adjustable non-tripping time delay from 0 to 10,000 ms.
What the ratings mean for fit
The 400 A rating means this module sits on the load side of a 3VA2 breaker sized for that current class — it's not a standalone device but a bolt-on residual current block for the SENTRON platform. The Type A designation covers AC sinusoidal and pulsating DC fault currents up to 6 mA smooth DC, which is the standard for most commercial and industrial circuits with electronic loads like VFDs, switched-mode supplies, and lighting ballasts. The adjustable residual current range of 0.03 to 30 A gives you selectivity: set it at 30 mA for personnel protection on a subfeed, or dial up to several amps for an equipment-grounding alarm on a main. The 10 selectable time delays from instantaneous to 10 seconds let you coordinate downstream RCDs so only the faulted branch trips, not the whole panel.
Deployment context
This module mounts via screw fixing to the 3VA2 breaker, not on a DIN rail — it's a direct busbar connection that bolts onto the load side of the MCCB. The IP40 front protection means it's suitable for enclosed panel mounting where the door or cover shields it from tool drops and dust; it's not rated for washdown or outdoor exposure. The infeed can come from top or bottom, which simplifies busbar routing in a crowded enclosure. At 75 W maximum power loss, it dissipates noticeable heat — allow ventilation clearance around the module, especially when the breaker is running near its 400 A rating.
Signal and communication features
This RCD820 includes both an electrical trip indicator and a communication trip indicator, so you get a local flag on the module plus a remote signal for the PLC or BMS. It supports remote-controlled tripping and communication with upstream residual current monitoring equipment. The integrated alarm management provides a pre-alarm at 30% and 60% of the set residual current threshold — useful for predictive maintenance before a nuisance trip takes a line down. The module can operate in selectable RCD or monitoring mode, meaning you can configure it to trip on fault or simply alarm without disconnecting the load.
Environmental and physical constraints
The module spans 138 mm wide, 150 mm high, and 110 mm deep — account for that depth when planning gland plate clearance behind the breaker. Ambient operating range is -40 °C to +80 °C, so it handles both cold storage areas and hot transformer rooms without derating. The housing is sealable for tamper-proofing after commissioning.