This is what makes them smart and allows you to use your phone or other gadgets such as SmartSwitch Lite to control them. How do Smart Bulbs help?Ī smart bulb has all the electronics inside it to allow it to effectively switch itself on and off (as well as dim and perhaps change colour if it supports it). If you were to directly swap a traditional switch that uses light-first wiring, and therefore has no neutral at the switch, then the power for the lights would be running through the switch which it is not capable of supporting. SmartSwitch Lite requires a neutral to power it. If you don’t see a blue cable with brown tape but you only have one blue and one brown cable (for that circuit), then you still likely don’t have a neutral and the switched live has just not been marked with brown tape. If you have switch-first wiring, then you will have the cable coming from the consumer unit and the cable going to the switch. Firstly, if you see a blue cable with brown tape, then that’s a switched live and you likely don’t have a neutral. Most of the time, you can tell whether you have a neutral at the switch or not by removing the switch and having a look at the wires inside.
How can I tell if I have light-first or switch-first wiring and whether I have a neutral? Once you have got a live and neutral to the first switch by following the latter steps, you can send the same live and neutral to the second switch. You should focus on the first switch which wires to the light, safely disconnecting the second one. If the light in question can be switched from two locations then first work out which switch wires directly to the light (the first switch) and which switch just wires to the other switch (the second switch). The live from the light to the switch uses the brown wire, then the switched live uses the blue wire and is normally marked with some brown tape to indicate it is actually a switched live and not a neutral.
We refer to this as “light-first wiring” which means you do not have a neutral at the switch. Traditionally in the UK, this is wired such that the live (brown) and neutral (blue) wires (old houses may have red and black cables respectively) from the main power source (the incoming power) go to the light fitting first, then the live is sent to the switch and finally the switched live (the live that is made and broken) is sent back to the light. First, what is a neutral and why might I not have one?įor a traditional switch to turn a light on and off, it needs to make and break the circuit. In this case, red is normally live and black is normally neutral. In some older buildings, you may have red and black cabled in the UK. Shortcut (TL DR): Fig.1 is what most UK homes have and Fig.4 is the tweak to get a neutral to the switch and permanently energise the bulbs. Make sure you turn off any electrics at the consumer unit before working on them and test with an appropriate tool that the circuit is not live. Even if you think you know what you are doing, you could be wrong. Warning, electrics are dangerous and you should seek the help of a qualified electrician. Getting a neutral wire to your switch brings connotations of ripping walls apart and turning your home into a building site, but that does not have to be the case as we discuss below.