How to Replace a Light Switch

2024 Author: Samantha Chapman | [email protected]. Last modified: 2023-12-17 09:13

You may find that you need to replace a light switch for several reasons, such as if it is too dirty, damaged or out of date to be used again. Or because you are about to sell your house and want to make it more attractive; or, again, why you would like your apartment to be more efficient. Changing the switch model is also an excellent opportunity to evaluate other possibilities connected to it, such as rheostat switches, connections, presence detectors and a set of other accessories that can increase the comfort, liveability and efficiency of your home.. Learning how to replace a light switch is fairly simple and can save you the cost of an electrician.

Steps

Part 1 of 3: Changing a Single Pole, Single Contact (SPST) Switch

Step 1. Buy a new switch, suitable for the use you want to make of it, at the nearest store of technical products for the home

Tell the clerks which and how many switches you need, they will be able to guide you in purchasing the best parts for your needs.

Single pole switches are the easiest to handle and also the most popular in homes. Such a switch has only two positions - “open” (off) and “closed” (on)

Step 2. Before operating, turn off the main switch on the electrical panel (also called the control unit) of your home

Usually, it is a panel embedded in the wall of the house and can be found both inside - in the cellar or garage, if your home has one - and outside. Depending on the complexity of the control unit, you can choose whether to interrupt the power only in the area of the house where you are working (by deactivating the relative switch) or throughout the home (by deactivating the main switch).

Step 3. Test the switch

Press the switch several times to check that the electricity has been properly turned off.

Step 4. Remove the front plate

Using a flat head screwdriver, remove the screws that hold the switch plate in place. Turn the screwdriver counterclockwise to unscrew.

Step 5. Remove the switch block

Once the plate is removed, use a flat head screwdriver to remove the screws that hold the switch block anchored to the wall. Unscrew counterclockwise until you can pull the screws out of the holes.

Step 6. Remove the old switch

Extract the switch block from the wall to handle the electrical cables. Before proceeding, do a new check with the multimeter to make sure that there is no passing of electric current.

• If you are using a multimeter, place one of the leads against the earth wire (green and yellow) while, with the other, test each of the two terminals (located behind the switch block).
• If you have a voltage tester, simply hold it close to the cables.
• If the multimeter signals the presence of electricity, stop immediately and try to figure out how to turn off the power to the home system.

Step 7. Remove the switch block

Pull it as far as the electrical wires allow.

• Pay attention to how the switch is connected to the electrical system. The cables will be fixed to the switch via clamps closed with screws or interlocking.
• Take a picture or draw a diagram of the wire connection, so as to mount the new switch in the same way.

Step 8. Check the wires inside the electrical box and identify them

Use a marker or colored tape to label them, so as to distinguish them from each other without making mistakes.

• The electrical box will contain one or two cables (sheaths containing the system wires). If the box contains two cables, it means that the switch is in the middle of the electrical circuit. You should see a total of six wires: two brown (the phase; but they can also be black or gray), two yellow and green (the earth) and two blue (the neutral).

  • Mark the wire either brown or black or gray as "phase".
  • Mark the blue wire as "neutral".
  • Finally, label the yellow and green wire as "ground".

• If the electrical box contains only one cable (or only three wires), it means that the switch is at the end of the electrical circuit. There will therefore be a brown wire (or black or gray: the phase), a yellow and green wire (the earth) and a blue wire (the neutral).

  • Mark the wire either brown or black or gray as "phase".
  • Mark the blue wire as "neutral".
  • Finally, label the yellow and green wire as "ground".

  Step 9. Free the wires from the old switch

  The wires are connected to the switch block via screw terminals located on the back of the block itself. Some models have interlocking sockets where to insert the wires.

  • If the new switch has both terminals and holes for interlocking, follow the advice of many electricians and use screw terminals for a safer connection. Do not over tighten however, you could damage the switch. If you hear a snap while tightening the screws, immediately discard the switch and use another one.
  • If the wires are tied to the old switch by means of screw terminals, loosen each screw and then extract the wires with the help of a pair of curved nose pliers or an electrician.
  • If the wires are connected by connectors, the interlocking holes in the switch block should have a small slot under them. Pry a small screwdriver into these slots to unlock the wires.

  Step 10. Start connecting the wires to the new switch

  First, connect the phase wire (brown or black or gray in color). Proceed like this:

  • Using electrician pliers, twist the copper conductor wires clockwise around the terminal screw and then tighten the screw to secure them in place.
  • Or push the wire into the connector's interlocking hole.

  Step 11. Connect the blue wire (the neutral)

  Proceed like this:

  • Using electrician pliers, twist the copper conductor wires clockwise around the terminal screw and then tighten the screw to secure them in place.
  • Or push the wire into the connector's interlocking hole.

  

  Step 12. Connect the green and yellow wire (the ground)

  Use electrician pliers to twist the copper conductor wires clockwise around the terminal screw and then tighten the screw to secure them in place.

  

  Step 13. Check the orientation of the switches

  Usually, the "off" position is upwards.

  Step 14. Carefully fold the wires inside the electrical box, then reposition the switch and secure it with the screws

  Step 15. Put the faceplate back on and screw it to the wall

  Do not over tighten the screws, you may break it with pressure.

  Step 16. Go to the controller and turn on the electricity

  Return to the new switch and try it several times to verify that it is working properly.

  Part 2 of 3: Changing a Diverter

  

  Step 1. Take a picture or make a note of how the wires are connected to the diverter

  A diverter is a type of switch (SPDT: single pole, double contact) that allows you to control the switching on of a light, or other device, from two or more points.

  The switch may have either screw terminals or interlocking connectors, both located on the back of the block

  

  Step 2. Identify and label each wire

  A diverter requires three wires: the phase and two returns. In the case of lights that can be activated by several switches, the neutral (blue) and earth (green-yellow) wires stop at the first box, the one closest to the light, and from there they go directly to the lamp holder. According to the position in the general electrical circuit, the box can contain one or two cables (or groups of wires, if these are not protected by a single sheath).

  • Recognize the wire carrying the current - the phase -; it should be connected to the center clamp (often marked with the letter L). The phase wire is black or brown or gray in color.
  • The other two wires are called returns and regulate the correct functioning of the connection between the diverters.
  • In the main box, often the one closest to the light point, you will also find the neutral (blue) and earth (yellow-green) wires. These wires do not enter into the deviators discourse, but are to be connected directly to the lamp holder.

  

  Step 3. Disconnect the wires from the old switch

  • If the wires are tied with screw terminals, loosen each screw by turning it counterclockwise with a screwdriver, then pry the wires out with a pair of bent nose pliers or electrician.
  • If the wires are connected by connectors, the interlocking holes in the switch block should have a small slot under them. Pry a small screwdriver into these slots to unlock the wires.

  

  Step 4. Connect the wires to the new switch

  • Connect the phase wire (black or brown or gray) to the central terminal (recognizable by an L printed on the plastic).
  • If the box contains two cables or groups of wires, connect the returns to the other two terminals (the position does not matter). Proceed: A) using electrician pliers to twist the copper conductor wires clockwise around the terminal screw and then tighten the screw to secure them in place; or B) pushing the wire into the interlocking hole of the connector.
  • If the box contains a cable or a group of wires, connect the returns to the other two terminals (the position does not matter). Proceed: A) using electrician pliers to twist the copper conductor wires clockwise around the terminal screw and then tighten the screw to secure them in place; or B) pushing the wire into the interlocking hole of the connector.

  

  Step 5. Check the orientation of the switches

  Usually, the "off" position is upwards.

  

  Step 6. Carefully fold the wires inside the electrical box, then reposition the switch and secure it with the screws

  

  Step 7. Put the faceplate back on and screw it to the wall

  Do not over tighten the screws, you may break it with pressure.

  

  Step 8. Go to the controller and turn on the electricity

  Return to the new switch and try it several times to verify that it is working properly.

  Part 3 of 3: Changing a Foot Switch (or Dimmer)

  

  Step 1. Identify and label each wire in the electrical box

  A rheostat switch (or dimmer) is an electronic regulator that allows you to control the brightness of a light point. Use a marker or colored tape to label each strand uniquely.

  • Mark the wire either brown or black or gray as "phase".
  • Mark the blue wire as "neutral".
  • Finally, label the yellow and green wire as "ground".

  

  Step 2. Disconnect the wires from the old switch

  The switch may have either screw terminals or interlocking connectors, both located on the back of the block.

  • If the wires are tied to the old switch by means of screw terminals, loosen each screw and then extract the wires with the help of a pair of curved nose pliers or an electrician.
  • If the wires are connected by connectors, the interlocking holes in the switch block should have a small slot under them. Pry a small screwdriver into these slots to unlock the wires.

  

  Step 3. Connect the wires to the new switch

  • Strip the sheath if you need more copper wire for the connections.
  • Connect the black (or gray or brown) wire of the phase.
  • Connect the wire (often white, but may have other colors) going towards the light.
  • Usually, the neutral and ground lines connect directly with the lamp holder. Most modern dimmers have fuses to protect the line, as they are not directly connected to earth.
  • Wrap the copper wire around the screws and tighten with a screwdriver.

  

  Step 4. Check the orientation of the dimmer

  Often these devices have various types of graphic indications to highlight the brightness scale. Mount the switch so that these indications are clearly legible.

  

  Step 5. Carefully fold the wires inside the electrical box, then reposition the switch and secure it with the screws

  

  Step 6. Put the faceplate back on and screw it to the wall

  Do not over tighten the screws, you may break it with pressure.

  

  Step 7. Go to the controller and turn on the electricity

  Return to the new switch and try it several times to verify that it is working properly.

  Advice

  • If the switch does not work, you may have made mistakes with the connections. In this case, ask for the assistance of an electrician. In the meantime, do not touch the switch and keep it off.
  • If the switch does not fit into the electrical box, try shortening the wires or using smaller connectors.
  • Wear shoes with plastic soles and use tools with plastic handles.
  • Make sure you install the switch perfectly vertical.
  • Particularly old homes may not have the yellow-green earth wire. In that case, you will have a vacant terminal. However, there are systems equipped with fuses that can be connected to the system instead of the earth.
  • If you need to strip the wires to expose the copper conductor, use the stripping pliers.
  • To connect the wires to screw terminals, you may find it easier to wrap the copper conductor around the screws themselves with a clockwise knot (using a pair of electrician's pliers) before tightening the terminals.
  • To remember where to insert each wire, untie them one by one from the old switch and insert them accordingly into the new one in the exact same position.
  • For added safety, cover bare copper wires and terminals with electrician's electrical tape.

  Warnings

  • Note that not all dimmers are compatible with compact fluorescent bulbs (LCF).
  • If you feel unsure what to do, don't hesitate to call a professional electrician.
  • Handling electrical cables can be dangerous to your health, so use all necessary precautions when working with wires or switches.