Consumer Units

A fuse board or otherwise known in the industry as a consumer unit, is the focus point within your home for your domestic electrics. It is the point at which all your domestic circuits start from and is designed in such a way that it provides protection to your electrical installation. Modern consumer units also provide a degree of protection for yourself as the consumer and can include devices to help protect some of your more valuable electrical items.

Consumer units have been around ever since the first lightbulb was installed within a domestic property. Over the years, the manufacturing process behind the consumer unit itself, and its internal components, have changed quite dramatically. One of the biggest changes in current regulations is now to provide, upon installation, a consumer unit that is made of metal. This is mainly to stop the spread of fire should there be a fault within the unit itself.

Modern consumer units also provide a degree of safety to the consumer and the household, with the use of miniature circuit breakers (MCBs), residual current devices (RCDs), residual current operated circuit breakers with overcurrent protection (RCBOs), arc fault detection devices (AFDDs) and surge protection devices (SPDs).

A miniature circuit breaker also known as an MCB is the first line of defence  for protection of your property and its associated wiring. The modern MCB originates from the older style fuse where you would have to change the fuse wire if it burnt out. These older style fuses did the job that they were designed for as well as could be expected, although it was easy to put the wrong size fuse wire into the fuse and this could potentially lead to a fire somewhere within the property. They also had a habit of setting fire to the fuse board itself especially when they were made of wood and painted with a non-fire-resistant paint.

The modern MCB incorporates new technology which negates the need for manual wire replacement. It is also an enclosed unit that provides a high degree of protection from the risk of fire should the MCB trip under fault conditions. We can also reset modern MCBs with the flick of a switch.

A residual current device also known as an RCD is used within the consumer unit mainly to protect the end user from harm, although this is providing that the RCD fitted is of the correct type. If there was to be an unexpected or accidental fault / imbalance within the supply, then it will cut off the power before it causes you any harm. The RCD is thought of much the same as the invention of seat belts within a car. Would you drive down the motorway at 70 mph without having your seat belt on? Well, we certainly wouldn’t, so perhaps taking the risk of not having RCD protection within your home just isn’t worth it.

If you choose Ely Electrical Ltd to fit your new consumer unit, as per the current regulations we will always install a consumer unit that incorporates A type RCD protection.

A residual current operated circuit breaker with over current protection otherwise known as an RCBO, is a device which incorporates the previously mentioned MCB and RCD. The benefits mean that if a fault or hazardous condition should occur, it will only disconnect the power from that specific circuit and not necessarily cause other power circuits to switch off. This is especially useful if you have a power cut during the night or evening where ideally you may lose your lighting but hopefully still have power to your sockets or vice versa.

An arc fault detection device also known as an AFDD, incorporates the previously mentioned RCBO and provides protection against arcs. An arc is usually caused by a faulty or loose connection between two wires, a break in a wire or where a wire is terminated into an accessory such as a light fitting, light switch, a socket or even at the consumer unit itself. Now whilst an arc is not a direct threat to the consumer, it can cause an indirect hazardous condition mainly as it can cause a fire anywhere within the property and that is certainly something we all want to prevent.

A surge protection device, also known as an SPD, is a small device that is now, as per current regulations, installed within a new consumer unit. An SPD will, under fault conditions such as a lightning strike or surge from an outside source, automatically direct any overvoltage to the earth supply for your installation. This aims to prevent damage to voltage sensitive equipment such as your tv, computer or anything containing a circuit board which, these days, is found in almost every appliance.