What Is A Switch Loop & How Does It Work?


If you’re not a qualified electrician and have no real experience or understanding of electricity, then you should always have the contact number of a good emergency electrician on hand; just in case. However, it is always a good idea to understand how these systems work; it can help you to understand what your electrician is talking about and even deal with small issues yourself.

The switch loop is one of those issues. In essence it is very simple but you need to understand what it is and how it works.

The Switch Loop


In simple terms this is an electrical circuit that connects a light fitting to a switch, allowing you to turn the light on and off as you please. The switch can be a cord type or a standard wall switch. You could even wire it to a sensor if you wished. The main factor in a switch loop is that two cables will become live.

How It Works

In most circuits there are three cables, a live, a neutral and an earth. In the case of the switch loop these cables arrive at the light fitting. If you connect them to the light fitting the light will be permanently on; unless you switch it off at the fuse box.

Instead of this the power is directed to the switch and then back to the light.

Wiring Your Switch Loop


You should be aware of the latest electrical wiring regulations to ensure you get the cabling color and quantity correct. The live wire comes to the light fitting but connects to the fourth wire in a separate piece of wiring that runs from the fitting to the switch. This becomes a live wire and should be marked as such with tape at each end.

The neutral from the feed to the fitting and the neutral coming from the light need to be joined at the fitting; ensuring the neutral fitting point is connected. You can then do the same for the earth wires.

The taped wire at the switch is live and need to be connected to the live in feed on your switch. You can then connect the usual live wire to the live out terminal at the switch and the live in at the light fitting.

When you turn the switch the light will turn on or off. Be certain to connect all the wires properly, loose strands of cables can causes short circuits which should trip your fuse but can cause a fire.

You may hear the term switch leg mentioned. This is simply the live wire that runs from the switch to the fitting.

If you decide to create a switch loop yourself it is essential that you keep the electricity off until you have completed the wiring. It does make life easier in your home but it is also dangerous if done incorrectly. If in any doubt it is advisable to call the professionals for help.

Article Submitted By Community Writer

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