Test and Reset buttons, test button is for safety checks, and manual reset;
Provides residual circuit protection
Latching RCD (Sometimes called Passive) – When the power is lost due to an earth fault, the RCD trips out and isolates the circuit it is protecting. Latching RCD’s do not trip during power cuts so they are great for fridges and freezers and also for protecting remote/unmanned areas. This would also make them ideal for protecting some heating equipment set to “Frost Protection”, fish tanks, battery charging, and the protection of remote or unmanned areas.
PASSIVE RCD-AUTOMATIC RESET AFTER POWER OFF AND POWER ON BACK