What Is a RCD Socket?

Residual Current Device (RCD): Under normal operating conditions, the load is switched on and off; and when the circuit's residual current reaches its specified value under specified conditions, it causes the contacts to act and disconnect the main circuit. Kind of protector. The residual current device may be a combination of various components that detect the residual current and turn on and off the main circuit current.

RCD

(Residual current device English abbreviation)

Residual Current Device ( RCD ): Under normal operating conditions, the load is turned on and off; and when the residual current of the circuit reaches its specified value under specified conditions, the contacts are caused to operate and the main circuit is disconnected Kind of protector. The residual current device may be a combination of various components that detect the residual current and turn on and off the main circuit current.

Residual Current Device ( RCD ) is a leakage protection device.

The figure below is a block diagram of the leakage protection device.

The following figure is the electrical principle of leakage protection of a three-phase four-wire power supply system. In the figure, TA is a zero-sequence current transformer, GF is the main switch, and TL is the shunt release coil of the GF switch.

In the case that the protected circuit works normally and no leakage or electric shock occurs, it can be known from Kirchhoff's law that the phasor sum of the primary current through TA is equal to zero. That is, at this time, IL1 + IL2 + IL3 + IN = 0, no induced electromotive force is generated on the TA secondary side, the leakage protection device does not operate, and the system maintains normal power supply.

When a leakage occurs in the protected circuit or an electric shock occurs, due to the existence of the leakage current, the phasor sum of the load current of each phase through the primary side of TA is no longer equal to zero, that is, IL1 + IL2 + IL3 + IN 0 generates residual current, TA The secondary side coil has an induced electromotive force. This signal is processed and compared through an intermediate link. When the predetermined value is reached, the main switch shunt release line TL is energized, the main switch GF is automatically tripped, and the protected circuit is quickly cut off. Power supply for protection.