General description

This unit combines the over current protection of the “YUANKY”mcb with an electronic r.c.d capable of high sensitivity operation with special fail-safe features. The unit is ready for installation in “YUANKY”SPN type A or type B boards operating on single phase 240V system. The unit provides single-phase protection against overload short circuit and earth leakage currents.

Overcurrent protection

Overcurrent protection to circuit conductors is provided by thermal and magnetic tripping elements is the line side, equivalent to the “YUANKY”mcb and is available in both M3&6 versions. Operating characteristice on over current(the time currentcurves) are as for the “YUANKY”standard m.c.b.This section of the unit complies with the requirements of BSEN60947-2 for miniature circuit breakers, short circuit requirements comply with BS4293.

Earth fault protection

The r.c.d elment of the device provides core-balance detecton of the different between line and neutral currents and amplification to provide high sensitivity.

Operation of the test button

This check is made aftor installation with all shields and covers in place, and requires the MCB/RCD and the main supply switched on. Pressing the button marked “T”on the MCB/RCD applies a simulated earth-fault to the MCB/RCD which should trip instantly. This should be checkde frequently, at least quarterly. If the MCB/RCD fails to trip seek expert advice.