What it is and what it does
The Siemens 3VA9324-0RL30 is a SENTRON RCD820 advanced residual current protection module — a Type A RCD designed for load-side mounting on 3VA2 molded-case circuit breakers. It handles a rated operational current of 400 A across 4 poles, with an adjustable residual current range from 0.03 A up to 30 A, covering applications from basic personnel protection (30 mA) through equipment protection at higher thresholds. The adjustable non-tripping time (tv) spans 0 to 10,000 ms, letting you coordinate selectivity with downstream RCDs or tolerate brief leakage pulses without nuisance trips.
Key ratings and what they mean for your panel
The 400 A rating at 50/60 Hz means this module sits on the load side of a 3VA2 breaker sized for a main feeder or large subfeed — it does not interrupt fault current itself; the upstream breaker handles that. The 4-pole configuration covers three-phase-plus-neutral circuits, common in industrial and commercial distribution. The adjustable residual current (0.03;0.05;0.1;0.3;0.5;1;3;5;10;30 A) lets you set the trip threshold to match the actual leakage profile of the connected loads: 30 mA for personnel protection on final circuits, higher values for feeder protection where distributed leakage is expected. The adjustable time delay (0;0.06;0.15;0.3;0.5;1.0;2.0;3.0;5.0;10.0 s) enables selective coordination — set a longer delay upstream so a downstream RCD clears first, keeping the rest of the distribution live. The module includes a pre-alarm indication at 30% and 60% of the set residual current value — useful for predictive maintenance on systems where leakage drifts over time (aging insulation, moisture ingress). It also supports remote-controlled tripping and communication with residual current equipment, meaning it can integrate into a building management or SCADA system for monitored earth-leakage protection rather than just standalone trip. The infeed can be connected at the top or bottom of the RCD component, giving flexibility in busbar routing inside the panel.
Panel integration and mounting
This is a screw-fixing accessory designed to mount alongside a 3VA2 breaker — not a standalone DIN-rail device. It connects to the main current circuit via busbar connection, so panel layout must account for the busbar run between the breaker and the RCD module. The physical footprint is 184 mm wide, 150 mm high, and 110 mm deep. The front face carries IP40 protection — suitable for enclosed panel mounting where no water spray is expected. The module is sealable, which matters for installations requiring tamper-evident settings (e.g., healthcare, critical process).