Residual Current devices - RCD's

A residual current device (RCD) is the generic term for a device which monitors the current in the line conductor and the neutral conductor of a circuit in an earthed system.

For use in domestic, commercial and industrial installations.

In a normal healthy circuit, the vector sum of the live and neutral current values added together will be zero. Current flowing to earth, due to a line earth fault, will return via the earth conductor, and regardless of load conditions, will be registered as a fault.

This current flow will give rise to a residual current (Ires) which will be detected by the device. If the Ires exceeds the rated sensitivity of the RCD, it will automatically activate a tripping of the faulty circuit, thereby protecting people, equipment and buildings from the risk of electrocution and fire.

Residual Current Devices ( RCD's ) range

  • Sensivity
- from 10 to 500mA

  • Voltage
- 2 poles : 230V
- 3/4 poles: 230/400V

  • Connection capacity
- 25A: 6/10 mm² (flexible/ rigid cable) - 40,60A: 16/25 mm² - 80,100A: 35/50 mm²