Dual RCD boards are supplied with a main switch and two RCDs. Consideration must be given to circuit design in this scenario. You should not, for example, put all the lighting circuits on the same RCD as if a fault ever occurs then the RCD will turn off the whole bank of MCBs it’s protecting. This will mean you will be in complete darkness whilst trying to resolve the issue. RCD incomer consumer unit Earth Bar – This is the common connection point for all circuits’ earth cables. All circuit protective conductors will connect on the earth bar along with earth bonding connections If a consumer unit is located under a wooden staircase or in a passage way which is the sole route of escape then a coding of C3 would be logged. In all other situations no coding is required. When installing a metal consumer unit, does the metal lid that covers the protective devices have to drop down? This type of board is and should be the most common consumer unit being installed today. They are also the best type of consumer unit to choose to completely comply with 18th edition regulations. The major benefit of choosing a main switch consumer unit is you populate it with RCBOs and these devices give you individual protection of each electrical circuit. The majority of electrical contractors will recommend installing a main switch consumer unit following on from the 18th edition wiring regulations, as these boards are versatile and can be installed with RCBOs, surge protection devices and MCBs. Dual RCD consumer unit Main Switch – The main switch controls the electrical supply in your home, and allows you to isolate all circuits by simply turning it on and off. Everything within your consumer unit is controlled by the main switch

Enclosure – This is the ‘box’ all of the relevant accessories are housed in. Since the introduction of the 18th edition, all new installations must be in a steel enclosure SPD – Surge Protection Devices – They are now a requirement as part of the 18th edition regulations as it protects against surges into the electrics from outside the building. These are usually caused by lightning strikes, but can be caused by power surges from elsewhere down the electrical network. When this happens to your domestic fuse board it can be devastating to your home’s wiring. SPDs are installed between the outside feed and the main switch in your consumer unit and will trip if any inward surge is detected. There are four types of consumer units. The most common are the main switch consumer units and the dual RCD consumer units. Main switch consumer unit No, unless they are provided with the consumer units by the manufacturer. The use of them is not pre-cluded. Can a plastic consumer unit be fitted if it is enclosed in a steel enclosure?Yes, you have to ensure the supply tails enter the enclosure through an appropriate means to prevent damage to the insulation around the conductors. It is also important to tighten the tails that go into the incoming device within the consumer unit to the recommended torque settings, as set out by the manufacturer. Ensure the tails are fixed and secured so as to prevent disturbance. What coding is given to an existing plastic unit in good condition in an electrical inspection report? No, providing the IP integrity after the installation is maintained, which is IP4X on the top and horizontal surfaces, and IP2XC everywhere else. However, the use of fire retardant glands and trunking is not precluded. Do intumescent pads and strips have to be used when installing a metal consumer unit?

These are the big boys – a consumer unit on top of a consumer unit! This type of board is usually supplied as a main switch option only but there are RCD options out there if you look hard enough. Duplex consumer units have become more and more popular since amendment changes in the last few years and because of the improved knowledge of circuit separation (RCBOs). Flush Consumer Unit Neutral Bars – The common connection point for the neutral cables from the earth leakage protection devices (RCBOs)As to @The Happy Builder comments on being loose, that does not matter, we have an IP rating and not being able to be removed without tool. This is the most common consumer unit. These are metal and normally have a front lid hinged at the top, the size is completely dependent on the number of circuits you are having. (10 way, 14 way etc). Duplex Consumer Unit