Every household has light switches; they are used to control the house’s lighting; switches can be either plastic or metals. When installing or replacing an old switch, you will find an important disclaimer that says it’s crucial to ground your switches. Metal plates need to be grounded as metals are good conductors of electricity, but it’s not the same case for plastic switches.
Where Does the Earth Go on a Plastic Light Switch?
The earth is connected to the metal back box of the switch through the ground terminal screw in the back box of the plastic switch. If the switch plates are plastic, the earth wires are not connected to them because they are not good conductors, so you can’t be shocked by the plastic plate.
Meanwhile, suppose the plates of the switch are metal. In that case, they need to be earthed or grounded because metals are good conductors of electricity and can cause electrical shocks to the user; in the case, there is an overcurrent or short circuit condition in the electric circuit connecting the switch, the ground wire is connected grounding screw in the switch.
In addition, the metallic plates should be connected to the metal back box by a short length of wire to be more grounded and safer, even though it’s not required by regulations in case you have one screw lug at least. Still, it increases your safety and prevents electric shocks and injuries.
Plastic Light Switch VS Metal Light Switch Grounding
Plastic Light Switches
They don’t need to be grounded because they are not good conductors, so you can’t be shocked by the plastic plate; the ground wire is connected instead to the metal back box of the switch through the ground terminal screw in the back box of the plastic switch; meanwhile, metal switches require to be grounded.
Metal Light Switches
Since metals are good conductors of electricity and can cause electrical shocks to you if there is an overcurrent or short circuit condition in the electric circuit connecting the switch, the ground wire must be connected with a grounding screw in the switch backbox.
Old Houses’ Wiring
In old houses, you may need to replace some old switches, which can cause more problems than you thought; the new switches don’t come with a grounding wire, the metal plates are more preferred for old house wiring because they have ground wires, so you can connect the ground wire to the ground screw terminal in the metal switch.
On the contrary, plastic switches need a connector block to connect to the ground wire. The switch is then grounded; another advantage of metal switch plates is their durability. However, plastic switches are less durable than metal ones due to their materials which can be easily broken.
The Cost
The metal switches cost a lot more than the plastic switch, but they are worth their price because they are more durable, safer, and have easy installation than the plastic plates, especially in old houses’ wiring. In addition, modern plates don’t require the grounding cable to exist as they have a ground screw that disperses any overcharge.
Can You Ground a Light Switch Without a Ground Wire?
Yes, there is an alternative way to ground a light switch without a ground wire; you have to use a bare metal screw instead of the ground wire, many electricians use this way, but you have to be sure that your plates have a place to fit the screw in it. If you have an old house, you may already find some switches grounded this way.
Source
Do All Light Switches Need To Be Earthed?
No, not all light switches need to be earthed; for example, traditional toggle-type switches don’t need to be grounded; meanwhile, other types like dimmers need to be grounded. However, it is not illegal not to ground a light switch; the grounding step in a light switch wiring is an important safety step.
When installing new sockets and switches, there is always a disclaimer that says how important it is to ground every electrical component you use to protect you from electrical shocks and injuries. For example, if you unscrew any switch plate, you can see a lot of wires and cables; one of these cables is the ground wire.
What Happens if Light Switch Is Not Earthed?
When a light switch is not grounded or earthed electrical shocks possibility increases because, at overcurrent and short circuit conditions, the electric current seeks another shorter path than the intended path. Therefore, electrical charges can pass into your body because the human body is a good conductor of electricity.
The current naturally looks for a conductive surface like metal to flow through, so the ground wires provide a safe path for the current to pass through and protect the users from electrical shocks. In addition, the ground wires disperse the electrical charge into a safe place like the earth, away from people.
When the light switch doesn’t have a grounding plug, the current doesn’t have an alternative path to flow through, so there is a voltage affecting the conducting area; when you get close to this area, you are at the risk of getting injured or shocked. If you have the option to ground the switch, don’t hesitate to do it.
Especially if the switch plates are used in areas exposed to water regularly, like the kitchen or the bathroom, you can reach the switch while your hands are still wet, which puts you in danger of getting shocked.
Is It Illegal To Not Ground Light Switches?
No, it is illegal not to ground light switches; however, it may differ from one country to another, and the grounding of light switches depends on the local regulations. Many inspectors highly recommend that every light switch in the household be grounded; however, many households live safely without grounding their switches.
For example, buildings related to government or council-owned buildings must have their light switches grounded to pass the electrical inspection, follow the electrical regulation, and meet the requirements. Therefore, it’s the responsibility of the homeowner to decide whether the house switches are grounded or not.
Conclusion
To sum up, plastic switches don’t need to be grounded because they are not good conductors, so you can’t be shocked by the plastic plate; the ground wire is connected instead to the metal back box of the switch through the ground terminal screw in the back box of the plastic switch; meanwhile, metal switches require to be grounded.
Meanwhile, metal switches are good conductors of electricity and can cause electrical shocks to the user; if there
is an overcurrent or short circuit condition in the electric circuit connecting the switch, the ground wire has to be connected grounding screw in the switch backbox.
You can either ground the switch using a ground wire or a bare metal screw; a grounding screw is an alternative way to ground a light switch without a ground wire; you have to use a bare metal screw instead of the ground wire, many electricians use this way, but you have to be sure that your plates have a place to fit the screw in it.
Although it is not illegal to not ground light switches, however, it may differ from one country to another; the grounding of light switches depends on the local regulations, and light switches are recommended to be grounded for your safety.
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