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What is an RCD? Andover
What is an RCD?
What is an RCD?

What is an RCD?

RCD is short for Residual Current Device, its one of the most effective ways to protect yourself from an electrical accident. As we all know, electricity can cause catastrophic damage, in some cases it can be fatal.  By installing a Residual Current Device into your electrical system, you decrease the risk of an electric shock by a significant amount.

How does it work?

As previously mentioned, RCD’s are designed to protect you against electric shocks. But how do they work? An RCD continuously monitors the electric current flowing through live and neutral wires. The device will be able to identify any faults. For instance, If the live and neutral current becomes unbalanced, the RCD will detect this and cut the power instantly.

Types of RCD’s


Commonly found within a fuse box. Fixed RCD’s deliver the best protection against electrocution. Furthermore, fixed RCDs protect individual circuits and more complex setups which are part of multiple circuits.


Portable RCD’s can be relocated to wherever their required. These RCDs are generally used when installation options are limited. For example, on a constructions site. Portable RCDs are plugged into a wall socket outlet, from which an electrical device can be plugged into it.

Socket Outlet RCD

A socket outlet RCD will replace a standard socket outlet in your home or business. These outlets provide a much safer option for working with electrical devices. In addition, Socket outlets are commonly found in outdoor extensions cables.

What can trip an RCD?

RCDs are considered to be very reliable devices. In fact, studies have shown they prevent electric shocks in around 97% of all cases. However, as its not a 100% you should always be cautious when working with electrical appliances and RCD’s. Below are 2 of the best practices we wish to highlight.

Test the RCD device

All Residual Current Devices are designed with a built-in test button which enables the user to test the device before carrying out any work. We highly recommend all users to complete a test on each RCD once every three months. This regular testing will allow you to stay on top of potential issues. If the test button does not cut the power, you must contact an electrician to investigate this further.

Check your wiring

To prevent electrical accidents, any electrical installations including RCD’s must be checked every 5 or 10 years. Over time electrical writing can deteriorate causing circuits to easily malfunction. Therefore, its crucial for you to cover every base instead of solely relying on an RCD device.