Residual Current Devices (RCDs)

Residual Current Devices save lives by protecting you and your family from fatal electrical shock! They are the most effective way of protecting you and your family (and/or employees) from electric shock or electrical fire.


What are Residual Current Devices (RCDs)?

Residual Current Devices are often called “safety Switches” or sometimes (mainly by UK tradies) “earth leakage circuit breakers”.

Residual Current Devices or RCDs are sensitive electrical safety devices which are wired onto an electrical switchboard. When installed correctly, an RCD can detect any imbalance in the electrical current and is designed to disconnect quickly enough to prevent potential injury or death from electrocution by switching off the supply almost instantly if you get an electric shock ( within 10 to 50 milliseconds).

How do Residual Current Devices Work?

Residual Current Devices operate on the principle that “what goes in, must come out.” They continually monitor the current flow in both the Active (supply) and Neutral (return) conductors of an electrical circuit.If everything is working as it should, the electrical current flowing in the two wires is equal. When an earth leakage occurs due to a fault in the circuit or an accident with the equipment, an imbalance occurs and this is detected by the RCD, which automatically cuts off the power before injury or damage can result.

Types of Residual Current Devices

There are 3 main types of residual current devices.

Fixed RCDs:

  • safety-switch-installation-3 These are found on your switchboard (or consumer unit). They can be wired to single circuits or multiple circuits. Fixed residual current devices offer the most protection as they continually monitor all sockets on a circuit and any connected appliances.
  • Socket Outlet RCDs:108435-full-1These residual current devices are built into the socket outlet and they offer protection to the person in contact with the equipment plugged into them.
  • Portable RCDs: c97e6ef2-fa21-422a-a5b3-7a9983f82e00-1The Portable Residual Devices plug into any standard socket-outlet. An appliance can then be plugged into the RCD. These are useful when neither fixed nor socket-outlet RCDs are available. Once again they provide protection only to the person in contact with the equipment, including the leads, plugged into the portable RCD. However, they are certainly better than using no residual current devices at all.

Andrew and his team at Western Suburbs Electrical have many years experience in the installation and testing of Residual Current Devices. Do not hesitate to contact him on 04388 03446 to find out more or fill in the contact page by clicking here.