How to change a switch ?

Whether a switch is broken, sizzling or simply no longer in harmony with your interior decor, don’t hesitate to change it yourself. The operation is simple and will only take you half an hour. You don’t need to be a seasoned electrician to change your switch. Here are the steps to follow to successfully complete this small operation without difficulty.

The star tool: the screwdriver

If you have a flathead screwdriver, great; you could almost get away with it. But a few tools can be very useful to change your switch without stress. In your toolbox, also provide universal pliers (for cutting), stripping pliers, a cutter… And don’t forget the new switch to install!

Work safely

Don’t put yourself in danger! Before changing your switch, start by cutting off the power supply. The easiest way is to turn off the general circuit breaker. If you are familiar with the indications on your electrical panel, you can simply remove the fuse corresponding to the power supply zone of the switch.

If in doubt – for example in the case of an old installation -, do not hesitate to use a VAT (Voltage absence tester) or a multimeter. This will allow you to verify with certainty that there is no electrical current at the switch or socket.

Remove the switch to change

A switch box consists of Three parties : the rocker (that button you press to turn it on or off), the front (visible from the outside) and the frame (the inner part attached to the wall).

For some switches, you have to start by removing the rocker, then the front. Sometimes the rocker stays in place and you have to detach the faceplate first. In both cases, use your flat screwdriver to unclip the front.

Once this is done, you access the cadre of the switch. You can then unscrew the screws that hold it fixed to the wall and carefully remove the frame from the wall. Once freed from the wall, let the switch hang from the end of its electrical wires. Turn it over so you can access the wires.

Disconnect the electrical wires from the old switch

If the power supply is cut off, then you can unplug securely the electrical wires from the switch terminals. This is generally connected by two wires, both of which must be disconnected. Be careful to separate them: blue on one side, red on the other. The blue color corresponds to the neutral wire and the red is reserved for the phase. Attention, the phase is sometimes of another dark color (black, brown, orange, purple…) but the neutral is always blue.

If a third wire, yellow and green, is present, it is ground. It is found on switches operating back and forth. But most often a basic switch has neither earth nor neutral. You will always have a phase wire, most often red, and a second wire.

Connect the wires to the new switch frame.

Once disconnected, check that the wires are bare for about ten centimeters before wiring them to the new switch. For the connection, you will have to put the wires back in the right holes. Rest assured, an electrical diagram is usually drawn on the back of the box. Anyway, you have two wires to connect. Start by connecting the phase (red wire, sometimes black or brown…) to terminal L of the switch. The second wire takes place on one of the two remaining terminals. Depending on the terminal chosen for this second wire, the ignition will be done by playing the rocker up or down. When there is a blue neutral wire, it always goes into the N terminal.

For back and forth: double connection.

If you need to change a back and forth, the operation is hardly more complicated. This type of switch controls several lighting points in several places. You will therefore have two paired switches, A and B. To make your connection successfully, proceed as follows: connect the red wire to the L terminal of switch A. For the second wire, it must be connected to the terminal 1 of switch A to terminal 1 of switch B. Same thing for terminal 2: the second wire goes from A to B while remaining on terminal 2. As for the external connections, the red wire of the circuit breaker arrives on switch A (terminal L), while the L terminal of switch B connects to the lighting point (the lamp).

Close the new box and secure it to the wall.

With the wires properly connected, you can close the box switch by attaching its frame to the rear. The time has come to insert it into the wall cavity. If necessary, use a spirit level to check that it is horizontal. Then insert the new switch box in the wall. If it is a built-in model, push it to the bottom until it signals its correct insertion with a click. For a classic screw model, simply close it and fix it with the screws, making sure to tighten them well. Some models are fixed with claws, for which it is necessary to tighten the screws which control the claws.

Once the box is attached, check the solidity of the front attachment of reassemble the facade and the rocker. This simply clips on.

Test the operation

Your new switch is in place? You can re-energize the electrical circuit, either by moving the fuse previously removed, or by putting the main circuit breaker back into service.

Try turning on the light with your switch. If that doesn’t work, it’s possible that a wire was loosely connected, or that it slipped out of its hole when reassembling the assembly. If so, don’t forget to turn off the power before checking the connections…

If the light shines on the first try, congratulations, the installation is successful!

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