High-immunity RCDs

The AP-R range of residual current devices (RCDs) is designed with high-immunity characteristics to overcome the problems associated with unwanted tripping due to overvoltages of atmospheric or operational origin in domestic, commercial and industrial systems where service continuity is essential.

Often disturbances on the mains can cause an RCD to trip even though no true earth fault is present. The disturbances are often caused by transient overvoltages associated with loads starting, stopping or being switched, electric motors or fluorescent lighting systems.

The devices contain an electronic circuit that can distinguish between temporary leakage caused by disturbances on the mains and permanent leakage due to actual faults, while still adhering to the requirements of AS/NZS61008 for RCDs and AS/NZS61009 for RCBOs.

The surge resistance value of the device is 12 times that of a conventional RCD, with ratings of 3000 A based on an 8/20 wave.