Single screw point terminal - as the name implies, each terminal has just one large screw which is used to secure all the cable cores being joined together. Bus Bar screw terminals - with these types of terminals, each cable core has its own location hole and screw for securing to a terminal. The number of cores which can be joined is limited by the number of holes/screws in each terminal - these can vary from 2 to 6. If you have ever needed to join 2 sections of cable or wire together or create an additional spur for a new piece of cable then you should be well aware of the existence of the junction box and if not, this is the product you want if you are needing to do either of these jobs.

Electrical junction boxes come in a range of different types. There are two key differences that you will need to look out for when purchasing your junction box:Step 3 – Connect to Terminals: Once all stripped, connect each core wire to an individual terminal ensuring that each type of core is connected to the same from the other cable, e.g. a 3 brown lives in one terminal, all 3 blue neutrals in another terminal and all 3 earths in another terminal. Also ensure that you add earth sheath to each bare earth wire – This has to be done by law! The cable cores will need to be stripped before being inserted into the terminals. Try to expose the minimum amount of the conductor as necessary. 10 – 12mm will be typically sufficient for this, unless you are doubling them over then around 15mm is required. There are also different styles of junction boxes that you can use. Each will differ slightly depending manufacturer (terminal layout, slightly different mouldings etc….), but the essentials should all be the same: Junction boxes are rated in amps to protect them, you and the circuit. Make sure you have the right box for the right job. A ring main ( more about ring mains can be found in our project here) and also a radial circuit ( more about radial circuits in our project here) will need a 30 amp junction box, whereas a lighting circuit (although you can buy 5amp junction boxes) will need a 20amp junction box.

We will explain the differences between these types of junction box and their various benefits shortly, however it is important that you have the right rating whichever type that you choose. Junction Box Amp Rating Junction boxes can also be used to add lights and switches. For more information please see our lights and switches project. The rating that you use must reflect the current of the circuit that it will be used on. It is possible to use a higher amp rated junction box on a lower rated circuit, but never the other way around – To summarise: Likewise, the cables running into and out of the junction box should also be secured to a suitable, stable surface. If not, then “mechanical strain” could take place and over time, wires may become loose causing loose connections.For a lighting circuit use a 20amp junction box and for a ring main or radial circuit use a 30 amp junction box. Terminals In terms of accessibility, this means that a builder or electrician can easily remove part of the floor or ceiling etc. and access the junction box when required. Junction boxes may not be buried in plaster or other similar materials. A junction box is a type of electrical enclosure that allows you to safely and easily join 2 or more pieces of cable together and ensure that any connections and terminals are well hidden and protected from causing injury or fire. Junction boxes are rated in amps (typically 5, 20 or 30 amp). The size used should equate to the current rating of the circuit being connected into - you can always use a higher rated box than the circuit but never a lower rated box.