Once the junction box has been fixed to a secure surface, and the wiring has been connected to the terminals and tested you can close the junction box, they must never be left open and exposed. The cover is screwed closed using the provided securing screw (or possibly screws) through the cover and fixing it to the base. It is often necessary to adjust the wiring inside the junction box to allow the cover to close. Avoid simply forcing the cover closed with the screw as this can risk causing damage to cables. In this guide we take a look at junction boxes and how they are wired up and used, read on to find out more. Working With Electricity and Junction Boxes You can also read a brief synopsis on the electrical guidelines and what they mean by visiting our Approved Document P project here.

If this is the case you are asking the circuit to use much more energy than the circuit is designed for. More energy = more heat and cables can catch fire! Stripping the inner cores of the cable should be such that minimal conductor is exposed once the connection has been made. Each of the earth cores of the cables should be covered with green/yellow earth sleeving within the 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

Examples of Junction Box use

Step 2 – Cut and Strip Cables: The next task is to cut any cables where you will be installing the junction box (if this needs doing, you may just have 2 ends that just need joining). Once cut, strip the main outer protective sheath and then strip 12mm or so from the end of each core wire

For a lighting circuit use a 20amp junction box and for a ring main or radial circuit use a 30 amp junction box. Terminals One thing to watch out for with the number of terminals, is the type of terminal used. Two basic types are available: Use green and yellow earth sheathing to cover the earth which will most likely be bare at present. As commented, this is a legal requirement stated in the Wiring Regulations. Which Colour Wires are Which?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. 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: Junction boxes can also be used to add lights and switches. For more information please see our lights and switches project.

In short they are used for joining wires or running a spur from an electrical circuit safely. Whenever you need to join two or more electrical wires, then you should use a junction box. As a result they are commonly used and very useful for anyone involved in wiring and electrics.Increasingly common are the “Maintenance Free” Junction boxes. These are designed to replace the standard round junction boxes commonly use in household wiring. The reason that they have become so popular is that they can save nearly 75% of the time required to wire a traditional junction box.

The main reason for this change was to ensure that any cabling used from that point onwards would harmonise (be the same) as those used in Europe. As we have stated in the how to wire section above, junction boxes must be fixed solidly to a firm, suitable surface and must be accessible! These rules are stipulated in the latest 18th edition regulations and must be adhered to. Screw the base of the junction box to a joist or rafter through the securing holes indicated in the image below. The cover should always be fixed in place using the screw (or screws) provided - the position of the internal wiring may need to be adjusted to allow the cover to sit on the body of the junction box before securing - never use the cover screws to force the cover down onto the cables, this can cause damage. Examples of Junction Box use Step 4 – Fix and Close Junction Box: Once you have ensured that each terminal screw is screwed down nice and tight, screw the junction box to a nearby joist or timber and then screw the cap down on 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.

Terminals

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.