Residual-current circuit breakers (RCCBs) monitor electrical systems for leakage currents and disconnect power when unsafe levels of current to ground are detected. They prevent electric shock hazards and reduce fire risks. This specific unit is capable of interrupting fault currents in AC, pulsating DC, and pure DC applications. ### Electrical Specifications Rated current: 40 A. Rated residual operating current sensitivity: 30 mA. Type classification: Type B — suited for detecting both AC and various forms of DC leakage currents, including smooth direct currents from electronic equipment like rectifiers or EV chargers. ### Design Features Poles: 4-pole configuration designed for three-phase systems with neutral connection points included. Operation characteristic: Short-time delayed response allows differentiation between transient surges caused by harmless events and genuine fault conditions to avoid nuisance tripping during momentary disturbances. ### Technical Notes / Limitations - Only compatible with installations requiring Type B RCCBs; inappropriate for systems relying on less sensitive types like A or F classifications. - Designed with short-time delay but not instantaneous response — unsuitable where no delay is permitted by the installation rules. - Must always be paired with adequate upstream overcurrent protection; this unit does not handle overload scenarios itself. - Requires periodic testing via onboard test functionality to verify proper operation remains intact over time.
