Do Socket Back Boxes Have to Be Earthed?

The socket back box might seem new to you, and that’s okay because you cannot see it, although it exists in every household. It is a part of switchboards that contains all the wirings. Suppose you remove the front plate containing switches, power outlets, regulators, etc. You will see wires jumbled together. Many new to black boxes may wonder, do socket back boxes have to be earthed?

If the socket box is made of plastic, you don’t have to earth it. If it’s metal, you need to look at the screw lugs. Whether you need earthing depends on the screw lug types and numbers.

I will explain this in further detail in the rest of this article. Besides discussing do socket back boxes have to be earthed, I will also shed some light on the importance of earthing and try to explain the difference between earthing and grounding.

Do You Need To Earth Socket Back Boxes?

A socket back box is fitted into a wall. The box contains electrical wiring. On top of the box, the front plate of the socket box or switch, fan regulator, etc., is placed. There are usually two types of socket back boxes; metal and plastic. The earthing requirements for the two are different as well.

Metal socket back boxes are considered exposed conductive parts. An exposed conductive part that people can touch without getting electrocuted. But it can become live when insulation fails. In the case of the socket backbox, the insulation is the plastic front plate made of plastic. But if there is any malfunction, the plastic switch can conduct electricity which can cause an accident.

So, a metal socket box has to be earthed. However, the earthing method varies depending on the type of back box. There are usually three types of metal back boxes; a back box with two fixed lugs, a box with two adjustable lugs, and one with one fixed and one adjustable lug.

If your socket box has two fixed lugs, you won’t need any earth tail. When you attach the front plate of the box with metal screws, it will automatically earth the socket box. There’s a metal strip at the socket’s back connecting the earth terminal with the fixing holes, and the metal back box fixed lug through the 3.5mm metal screw.

If the socket box has two adjustable lugs, you need to install an earth tail from the socket earth terminal to the backbox because you cannot rely on adjustable lugs for proper earthing.

When your socket back box has one fixed lug and one adjustable lug; some confusion can arise. Installing an earth tail is not a must, but it is desirable. There is no clear explanation of what desirable means in this case. But I recommend installing an earth tail just like two adjustable lugs because it is better safe than sorry.

If the socket back box is made of plastic, you don’t have to earth it regardless of the lug types.

Why is Earthing Necessary?

Earthing is important for various reasons. Earthing protects people from electric shock. It also prevents damage to electrical appliances and also prevents potential fire hazards.

Other than these, there are some additional reasons why you should use earthing on specific electrical components. Here are those:

  • Metal is an excellent conductor of electricity. However, manufacturers can use metals inside electrical apparatus that are not meant to conduct electricity. This is possible by earthing. A separate path is provided for the faulty current, stopping the flow immediately.
  • An electrical circuit can fry if there is a power surge. Such instances can irreversibly damage your highly expensive electrical appliances. Earthing is essential to keep that from happening. The sudden surge of current flows in a different route to protect the vital components of an appliance.
  • The electrical system is linked to the overall earth mass’s potential and cannot attain a different value. The potential of the earth is zero volts, and it is known as the electricity supply neutral. Earthing aids in maintaining balance.

Types of Earthing

There are quite a few types of earthing, but two are the main basic categories of earthing; neutral earthing. Let’s take a look at them briefly:

  • Neutral Earthing: In neutral earthing, the neutral of the specified apparatus is connected to the earth, usually by a GI wire. Neutral earthing is also known as system earthing. This type of earthing is used in machines that have star winding. Neutral earthing is used in generators, motors, etc.
  • Equipment Earthing: This type of earthing is what we see in socket back boxes. The nonconducting part of the box is connected to the earth with a conducting wire. In case of a power surge, the short circuit current passes to the earth without damaging the component.

Other than these two, there are other earthing types like pipe earthing, plate earthing, strip earthing, etc.

Is Earthing and Grounding the Same?

Although the terms’ earthing’ and ‘grounding’ are used interchangeably, there are many differences between earthing and grounding. But, the primary difference is in what is being protected. Earthing is done to protect humans from getting shocked, while grounding is done to protect the electrical components.

Earthing is used in electrical appliances for protection against sudden surges and spikes. On earthing, the circuit is physically connected to the ground with a conducting wire to make the potential of the nonconducting part zero.

Grounding is somewhat similar to earth. The main purpose is protection from a power surge. However, the main goal is to protect the appliance rather than prevent electric shock. The main live wire that connects the appliance to the power supply, the other end of it is the led underground. This prevents overloading in case of an accidental cut in the circuit.

The following tables summarize the difference between earthing and grounding:

Hazards of Improper Earthing

The main hazard is the risk of losing lives. Electric shock is notorious for killing humans and animals in an instant. The human body has less resistance and is an excellent conductor. When insulation malfunctions, it’s easy to get an electric shock from otherwise harmless parts of an appliance.

You won’t expect your fan regulator to carry electricity. But when it does due to any mishap, earthing protects you from getting electrocuted. If the earthing is not right, precious human life can be at stake. Even if the victim does not die, he may suffer horrible injuries and potential lifelong limb damage.

Another danger of improper earthing is the damage to electrical appliances. While there is cheap electric apparatus, some household appliances are so expensive. Improper earthing can destroy all of them in a matter of seconds. Earthing carries the excess current to the ground keeping your appliance safe.


Proper earthing knowledge is crucial for saving lives and protecting the appliances you bought with hard-earned money. I believe that I could clear your confusion regarding whether socket back boxes have to be earthed and fulfill any additional relevant queries.

Thanks for stopping by.

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