Knightsbridge SN8420 20A Junction Box 4-Terminals White

Product Information

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. Stripping the inner cores of the cable should be such that minimal conductor is exposed once the connection has been made. 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

Single screw terminal – The terminal has one screw which is screwed closed on to the cable cores being joined together to secure them all in one single connection point. These are typically found in the Standard junction box, and allow the connection of a larger number or sizes of cable cores that the other terminal types A problem when purchasing Junction Boxes is to know which type of terminal is fitted and, where Bus Bars are fitted, how many cable cores can be connected to each terminal. Using Junction Boxes Step 1 – Isolate Power: Before doing anything at all, the very first job is to isolate the power to the circuit you are going to be working on! You can also read a brief synopsis on the electrical guidelines and what they mean by visiting our Approved Document P project here. Step 1 – Isolate Power: Before you do anything at all, first isolate the power to the circuit you are working on!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.

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. There is no requirement for a junction box to be either round or square, and they are commonly both. As a rule of thumb the more common round junction boxes are typically used for lower current cables. 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. Junction Box with spur wiring diagram – Adding a Spur using a Junction box Fixing cables into the Junction BoxWhen it comes to wiring up junction boxes, as you would expect, there are some quite strict rules on how they are wired, where they can be placed and how any cables should be secured. All of this is covered below. 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?