Difference between AC contactors and DC contactors

The AC contactors differ from the DC contactors in their construction, arc extinction, and usage in a circuit. In this article, let us discuss the major differences between AC contactors and DC contactors. Contactors are electrically controlled switching devices. They are used to switch electric motors, lights, reactors, capacitors, heating loads, EV charging systems, UPS, … 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

Ingress protection rating or IP rating (IEC 60529)

IEC 60529 has classified the degree of protection offered by an enclosure against solid particles and liquid. This classification is known as the ingress protection code/ IP code/ IP rating/ index of protection. To ensure the correct protection of the internal components and to suit the environment where the enclosure is installed, these codes are … 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

Ungrounded systems

An electrical system that is not intentionally connected to the ground is known as an ungrounded system. Even though the system is not connected to the ground, there exists a connection to the ground due to the presence of capacitances between the live conductors and the ground. Therefore the so-called ungrounded system is actually a … Read more

Neutral-to-Earth/ground Voltage- Causes, effects, and solution

Ideally, the voltage measured across the neutral and the earth/ground must be zero. But sometimes there exists some measure of potential difference between them. Here, in this article let us analyze the causes of neutral to earth/ground voltage, its effect, and how to mitigate it. Note: If you are an electrician troubleshooting your wiring or … Read more