The switch connects between the permanent live and the switched live terminal. The lamp is connected to the neutral and the switched live. 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

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 This method of wiring is not recommended. The main problem is that the junction boxes must remain accessible - rather difficut once they are hidden under floorboards. If normal ceiling roses are fitted, the terminals in them are largely wasted, and additional money has been spent on junction boxes which are not needed. 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. If you are using metal conduit to run wiring to the electrical box, then a metal box is required—both to anchor the conduit and because the conduit and metal box itself may be used to ground the system. Metal boxes are more durable, fireproof, and secure.Installations with plain green sleeving on the earth wires will typically be approaching 40 years old and are likely to require replacement. The KA series receives a complete revamp and is optimised to three sizes. The use of two types of plastics for the lid (PP) and base (PE) creates greater flexibility and ease of installation. As well as improved mounting options, as the KA series also adds cable retention through the use of a clever strain relief ring. Select the right junction box for the location. If the area the junction box will be located is exposed to moisture, be sure to choose a junction box designed for that purpose. Similarly, if the junction box will be exposed to fumes, such as in a paint shop, choose a junction box formulated for that type of usage. 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! You can also read a brief synopsis on the electrical guidelines and what they mean by visiting our Approved Document P project here.

Junction boxes can also be used to add lights and switches. For more information please see our lights and switches project.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 Internally, there are mounting points for screws in each corner, so you should use the correct masonry plugs, anchors and fixings for the surface you are mounting to such as a wall, skirting board or ceiling. 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!

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: To find the right size junction box in cubic inches, count the number of wires entering the junction box. Multiply the total by 2 when working with 14-gauge wire or by 2.25 when working with 12-gauge wire. Then, select the largest ground wire and add 2 if it is a 14-gauge wire to 2.25 if it is a 12-gauge wire. Choose a junction box with conductor fill volume (which is the number of conductors allowed in a junction box) higher or equal to the number of wires (after multiplying them by 2 and adding in the ground wire) entering the junction box. It’s best to choose a fill volume higher than the number of wires you have to ensure there will be enough room. [1] X Research sourceThe 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: When on, the switch is connecting the switched live and live terminals together (top and bottom in this example).