RCD's SPD's AFDD's and your safety

With the 18th edition of BS7671 upon us it is now more important than ever to consider how protected you are from the electricity in your home.

Here is a little guide to what devices are recommended and what it is they protect you from.

RCD (residual current device)

An RCD is a device that protects an installation and its end users from earth leakage current. The way it does this is by monitoring the currents in the Line and Neutral conductors. and will disconnect the electricity supply when there is an imbalance between these meaning that electricity is being lost or 'leaking'.

Why is this so important?

Leakage of electricity means that some of the current is being lost due to a fault in the system. That fault could be anything from an appliance starting to break down to a person (possibly you) touching something live.

SPD (surge protection device)

An SPD is a device which protects an installation from over voltages caused by an array of circumstances such as a transformer fault in the supply network to a localised lightning strike. it works by effectively dumping extra voltage and smoothing out the electricity supply. th only drawback is these are considered as a consumable item as they will only work a certain amount of times before needing replacement, there are indicators on the product to tell you when replacement is needed.

Why do i need this?

Modern electronic equipment is particularly sensitive to over voltage. A surge can cause literally thousands of pounds of damage in a typical home damaging televisions, games consoles, computers and many other appliances. An SPD really is a great line of defence and can be thought of as an insurance policy for your electronics. I know i for one would rather pay for my SPD to be replaced than for all of my electronics.

AFDD (arc fault detection device)

A relatively new type of device providing unparalleled protection against electrical fires.

a sophisticated device monitors each individual circuit for any arcing which is basically sparks which occur where there are poor connections. and shut of the electricity supply to the affected circuit, preventing a fire before it happens.

The downside is because these are fairly new technology they can be pretty expensive. but you try telling yourself they were too expensive when its too late. I truly believe these devices are going to revolutionise electrical safety and many disasters could be avoided before they start.


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