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What is an RCD ?

RCDs are one of the most important devices in your homes electrical installation. There job is to protect you and others from electric shock. In simple terms it monitors the electric current going in and out of it. If the RCD detects an imbalance it will trip and turn the electric off. This is why the electric some times goes off when a light bulb blows due to an imbalance.


There are many types of RCDs but the main ones you will find in your home is a type AC or type A. From September 28th 2022 the BS7671 Amd2 states all new circuits or alteration to existing circuits, would be required to be covered by a Type A RCD. Most RCDS will simply be a straight forward swap from the existing, however if you have an older fuse board then there may not be an equivalent Type A RCD available. This would then require a Fuseboard upgrade before any work could be carried out.


What's the difference between Type AC & Type A RCDs

The main difference between a Type A RCD and a Type AC RCD is their sensitivity to different types of electrical faults.

A Type A RCD can detect both AC and pulsating DC (direct current) faults, while a Type AC RCD can only detect AC faults. Pulsating DC faults can occur in electronic equipment that uses rectifiers, such as computers and TVs.

In other words, a Type A RCD provides additional protection against DC faults that a Type AC RCD cannot detect.


If you need a Local Electrician in Pontyclun. Contact Connor on 01443 305300


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