Residual current device (RCD)

RCD operating principle

The apparatus further tripping RCDs is intended to protect people from electrical shock, as well as the occurrence of fire which may occur when the electrical leakage due to poor insulation or poor electrical connections (EI).

RCD work, the contact is open and completely cut off the supply voltage on the protected line, provided that:

1 Human contact with dead parts EI be energized due to insulation breakdown.
2 Human touch live parts EI-energized.
3 Occurrences (differential) leakage current to earth or the EI housing to prevent fire.

1 The differential current transformer
2 The trigger
3 Actuating mechanism
4 "Test" button to control the proper RCD
I1 - I2 current direction in relation to the load
ID - Leakage Current
F1 - F2 magnetic fluxes

Appointment blocks.
1The differential current transformer (Used in most RCDs) measures the current balance between the conductors belonging to it.
2The trigger (Consisting usually of the electromagnetic relay) is used to control (feedback) actuator.

3Actuating mechanism designed for emergency stop electrical circuit controlled by the RCD.
4 "Test" button to control the health of the RCD by creating a simulation of leakage current.

The operating principle of the RCD

Description of the principle of the device:

Other articles on the electrics:

Connecting the magnetic contactor (relay)

Connecting the flow switch