1. What is an RCD?

An RCD or Residual Current Device is a life-saving device which is designed to prevent you from getting a fatal electric shock if you touch something live, such as a bare wire. It can also provide some protection against electrical fires. An RCD will automatically isolate electrical supply in the event of a fault.

2. How do RCDs operate?

An RCD constantly monitors the electrical current flowing through all circuits (MCB/Circuit breakers) that it protects. An RCD is designed to protect against the risks of electrocution and fire caused by earth faults. If it detects electricity flowing down an unintended path, such as through a person who has touched conductive part, the RCD will switch the circuit off quickly, most often within 30ms significantly reducing the risk of death or serious injury.

3.Types of RCD.

They will be able to provide advice on the electrical work needed, and arrange a dedicated time slot for an electrician to attend. Alternatively, you can request a call back and one of our team will contact you.
  • Fixed RCD

    what is rcd Fixed RCD’s are usually found within the fuse board (consumer unit). A fixed RCD provides the highest level of protection as it protects all the wiring and the sockets on a circuit, and any connected appliances.

  • RCD protected sockets

    These are sockets with built in RCD protection. This type of RCD provides protection only to the person in contact with equipment, including its lead, plugged into the special socket-outlet.

  • Plug in RCD

    Plug in RCD’s can be used as protection in any socket outlet it also provides protection only to the person in contact with equipment, including its lead, plugged into the special socket-outlet.

4. How to tell if your consumer unit is RCD protected.

An RCD will have a push button often marked with a ‘T’ or ‘TEST’. Pressing this button will isolate your electrical supply to fuses (MCB/Circuit breakers) that the RCD protects. If an RCD is fitted, there should also be a label on or near the consumer unit stating ‘test quarterly’.


Fixed RCDs are about 97% reliable. This improves if they are tested regularly. If you have fixed RCD protection, it will reduce the risk of electric shock to you and your family. It can also protect your home against the risk of fire caused by faulty wiring or appliances. RCD protection is also compulsory for circuits such as an electric shower. If you are concerned with your electrical installation, always contact a qualified electrician. They will advise you on what RCD protection you may require and any regulations. We provide RCD Protection as well as electrical emergency services, please contact us for more details.