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

Dual-element time-delay fuses

Time-delay fuses can provide overload and short circuit protection while overcoming momentary current spikes. They are used for the protection of motors and transformers. The time-delay characteristics of these fuses typically allow them to be sized closer to the running rated full load current of the loads. Time-delay fuses are also known as slow-blown fuses … Read more

Interview questions on Modbus

Below is the list of the most important interview questions on Modbus: 1. What is Modbus and how does it work? Modbus is an application protocol that defines rules for organizing and interpreting data and is essentially a messaging structure that is independent of the underlying physical layer. It is an open-source protocol and is … Read more

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