Various aspects need to be taken care of while building a commercial building or a manufacturing facility & lightning arrester installation and electrical earthing is one of those aspects. As this is concerned with the safety of the machines as well as the workers, it becomes even more important. But the thing is that despite getting electrical earthing systems installed in their facility, they are confused about what are the overall benefits of this system or whether they need electrical earthing or not. In this article, we are going to discuss these common things about electrical earthing. So, without any further delay, let’s get started.
What do you mean by electrical earthing or grounding?
Earthing or grounding means connecting the conductive parts of an electric appliance or electric installation to the ground or the earth. In very simple words, connecting the metallic parts of electric machinery or installations to the earth electrode or earth plate, which is usually buried in the earth with soil having more moisture level. This connection is made with the help of a thick wire that is having a low resistance. This arrangement is made for safety purposes and this is known as grounding or earthing. Under this system, the neutral point or end of the power supply system is connected to the ground to eliminate or reduce the danger at the time of discharge of electrical energy.
Sometimes the people get confused between earthing, grounding, and bonding. Thus, let us clear the basic difference between these terms, if any, so that confusion can be avoided. It should be clear that the grounding and earthing are the words used for earthing. Earthing is used mostly in Britain and European standards. However, grounding is the term used for earthing in North American standards. Bonding is the word that is used to express the joint between two wires or appliances or pipes together. This means connecting the metallic parts of different equipment or machinery which does not carry the electric current during the time of normal operation of the machinery.
Why earthing is important?
One of the most important reasons for installing the electrical earthing system in a facility is to minimize or avoid the chances of fire due to leakage of current in the earth and to ensure that the current-carrying conductor’s potential does not rise than the capacity for which it is built. When any surface of an electrical installation or appliance, usually metallic one, touches a live wire, then the metal surface gets accumulated with the static charge. This may be because of the failure in cable insulation or failure of installations. If a human touches this charged surface of the metal, then he will experience a sudden shock which may be of some unexpected level.This is the reason why some specific parts of the electrical appliances or the power supply system are required to be earthed, for ensuring that the charge of electrical energy gets transferred to the ground. That’s why there is a need to install an electrical earthing or grounding system. By doing this, any kind of damage to the workforce working on electrical appliances and electrical machines or to the expensive machines can be avoided. Thus, the following points can be discussed reflecting the basic needs of earthing:
- To offer protection to all the human lives working in a facility as well as to save the expensive machines from leakage current.
- To protect the buildings and electric systems from lighting.
- To keep the voltage constantly in the healthy phase.
- To avoid the risk of an electrical fire in the electrical installation systems.
Some basic terms used in electrical earthing
In this section, we will discuss some basic terms which are related to the field of earthing and every person should be aware of:
- Earthed: When an electrical installation or electrical device is connected to the earth via an earth electrode, then such a device is known “Earthed” or as an earthed device.
- Earth electrode: Earth electrode may be a conductor or a conductive plate that is buried in the earth for an electrical earthing system. Earth electrodes may come in different shapes like a conductive rod, conductive plate, or a metal water pipe.
- Earthing lead: Aconductive strip or the conductor wire which is used to establish a connection between the electrical installation system or earth electrode, is known as the earthing lead.
- Solidly earthed: When an earth electrode without any fuse, resistance, or impedance or circuit-breaker, is connected to any electrical installation or electrical appliance, then such installation or appliance is known to be solidly earthed.
- Earth resistance:This can be understood as the total amount of resistance between the earth and the earth electrode which is expressed in “Ohms”. This is an algebraic sum of the individual resistances of the earthing lead, earth continuity conductor, earth electrode, and the earth.
- Earth continuity conductor: This is a conductor wire which is connected among the different electrical appliances and devices such as different plugs, distribution boards, appliances, etc. In simple words, this is the wire between the electrical appliances or devices and the earthing lead. It may be in the form of a flexible wire or cable metallic sheath.
What if you didn’t earth an electrical system?
We have read in the above sections that earthing is done to avoid electric shocks and to make sure that any current-carrying conductor doesn’t exceed the potential as per the general earth mass than the insulation capacity for which it is designed. However, if the appropriate level of current is not earthed, then the electric appliances will get damaged because of having no fuse in place. It should be kept in mind that, at the generating stations, because of earthing excessive current, the earth wires carry no current or very little current. A small ignorance concerning the earthing system can lead to the loss of human life or damage to the machinery or equipment. Similarly, earthing is important for electrical appliances so that we don’t have to go through a severe shock. Not earthing an electrical system can also lead to an electrical fire which may damage the whole facility including the persons working in it. Thus, earthing is an aspect that should not be ignored at any cost. For this, one needs to consult good lightning arrester suppliers.