The Siemens 3VA9423-0RL30 is a SENTRON RCD820 advanced residual current protection module, designed as a load-side mounted accessory for the 3VA2 molded-case circuit breaker family. It is a Type A RCD, meaning it detects sinusoidal AC and pulsating DC residual currents — the standard requirement for most commercial and industrial distribution panels where electronic loads are present. Rated at 630 A operational current (AC) with adjustable residual current response values from 0.03 A up to 30 A, this module covers a wide range of earth-leakage protection requirements without swapping hardware. The trip time is also adjustable, with set values from 0 ms to 10 000 ms, giving the commissioning engineer flexibility to coordinate with downstream devices and avoid nuisance tripping on inrush or transient leakage. The module supports remote-controlled tripping and communication with residual current equipment, plus integrated pre-alarm indication at 30% and 60% of the set threshold — useful for predictive maintenance before a hard trip occurs. The infeed can be connected at the top or bottom of the RCD component, simplifying busbar routing in dense panels.
Panel Integration
Mounts via screw fixing to the busbar system of the 3VA2 breaker. The main current circuit connection is busbar-based, not lug or cable — verify that your panel's busbar layout accommodates the module's 138 mm width and 110 mm depth. Front protection is IP40, adequate for enclosed switchgear but not for washdown environments. The module is sealable (provision for a seal wire or tag to prevent unauthorized adjustment of the dial settings), and carries both electrical and communication trip indicators for remote status monitoring.