Methods of Ground/ Earth resistance measurements on existing systems

It is vital to maintain good ground in a system. In order to ensure that, ground resistance measurements and tests are conducted on existing earth electrodes at periodic intervals after their installation. This ensures the resistance in the ground is at an acceptable level and is maintained. Here are the different methods of ground/ earth … Read more

Soil resistivity measurement methods

One of the key elements affecting ground resistance is soil resistivity. Soil resistivity measurements are conducted before setting up an earthing system, in order to ensure an effective earthing. Good soil models are the basis of all grounding designs and they are developed from accurate soil resistivity testing. The ground/earth resistance measurements are conducted to … Read more

Grounding transformer or Earthing transformer

Grounding transformers are used to obtain a neutral when an existing delta-connected or ungrounded systems are to be grounded. These transformers provide a path for the flow of fault currents during unbalanced ground faults. They can be found in transformer substations where neutral might not be available as the transformer windings are delta connected. Types … Read more

Resonant grounded system (Ground-Fault Neutralizer)

A resonant grounded system can significantly reduce the ground fault currents. This grounding system basically consists of a tuned reactor connected between the neutral and the ground that resonates with the line-to-ground capacitance of the system so that the magnitude of the ground current is reduced. This reactor is knowns as a ground-fault neutralizer or … Read more

Reactance grounded system or inductance grounded system

In a reactance grounded system, the neutral is connected to the ground through an inductance (inductive reactance). The magnitude of the ground fault current can be limited to a value close to the three-phase short circuit current of the system (since it is a function of the phase to neutral voltage and the neutral impedance). … Read more

Types of Electrical Earthing as per IEC 60364 & BS 7430

Effective electrical earthing plays an important role in safeguarding people from the risk of electric shock and ensures a low impedance path for electric discharges to pass to the general mass of the earth under both normal and fault conditions. In this article, let’s discuss the various earthing systems as per IEC 60364 and BS … Read more

Are earthing and grounding the same?

Ground and/or Earth are generally used to define a common reference point for power/signal. While IEC (IEV ref 195-01-01) defines this reference point as earth, IEEE (Standard Std 142-2007) defines the same point as ground and NEC defines ground itself as a connection to the earth. But are earthing and grounding the same, let’s find … Read more

Resistance grounded system

A resistance grounded system or resistance grounded neutral system is one that employs an intentional connection between the neutral and the earth through one or more resistors. In these systems, the damage caused during a ground fault is far less than that caused during a ground fault in a solidly grounded system and the mechanical … Read more

Solidly grounded or Effectively grounded system

In a Solidly grounded system, the neutral is directly connected to the earth without any intentional resistance or reactance in between. Compared to the other grounding systems, the transient overvoltages are held to a minimum when the system is effectively grounded. In an effectively grounded system, ground fault currents will be considerably higher, making ground … Read more