Impact of Earthing in Electrical System Reliability

Importance of Electrical Safety & Earthing

Proper installation and maintenance of electrical equipment and the network plays a major role in reducing the electrical safety risk. The earthing system is an essential part of power networks at both high- and low-voltage levels. The earthing system is the total set of measures used to connect an electrically conductive part to earth. Poor earthing not only contributes to unnecessary downtime but also dangerous to human life and property. For example, a facility installed with Surge Protection Device (SPD) may face severe equipment failure if the earthing system is not maintained as per relevant standards and practices.

A good earthing system is required for:

  • Protection of industrial equipment’s and human life against high voltage.
  • Protection of buildings and installations against lightning.
  • Safety of human and animal life by limiting touch and step voltages to safe values.

Case Study

One of our clients was facing critical failures of CCTV and electronic devices, especially during lightning. Even the Surge Protection Devices (dedicated to outdoor electronic devices) in place was not successful in protecting their system. Frequent failures cost millions of INR and the facility was unable to figure out the gaps in the electrical system which is leading to failures. The facility was facing this for a long time. We conducted a study at the client’s site to identify the root cause and recommend suitable solutions which will help to avoid failures of electronic devices.

As a part of the study, we found Neutral to Earth Voltage above 30V at different locations, which is abnormal. While inspecting the earthing network, we have found a poor connection between the earth plates and the earth pit rod. Several other earth pits were also found to have gaps in the connection between earth plates and the pits. When this gap increases, the resistance increases and will not serve the purpose of earthing.

Gap between earth plates

This clearly indicates improper installation, commissioning and lack of maintenance. A good earthing system must have minimum resistance so that the potential is also minimum. This can be obtained by proper installation and commissioning as per relevant standards, periodic maintenance and by consulting experts to resolve any problems.

We’ve given the recommendation to fix all the connections in the earthing network, conduct period inspection of the pits & earthing network and to install SPD at locations where it should be installed for protection against surges due to lightning or any other disturbance which create surges. The selection of the SPD is very much important factor and the earthing system also should support SPD for the effective operation of the SPD at the time of any disturbance. An SPD installed with a poor earthing system will be ineffective and waste of money.

The topic we have discussed so far is a small portion of the gaps identified during the study to show the importance of proper installation, commissioning and periodic inspection or maintenance of the earthing system.  In any electrical installation which may threaten human life and property. Conducting an Electrical Safety Audit with experienced professionals will help to identify gaps, reduce electrical safety risk, avoid downtime, save cost and avoid risking human life.