A complete Electrical Engineering portal
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 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
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
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
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
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
Electromagnetic induction is a phenomenon by which electromotive force is produced across a conductor placed in a varying magnetic field. It was discovered by Michael Faraday in 1831 after performing several experiments for over 10 years in his laboratory in London. The discovery of electromagnetic induction led to the invention of electric transformers, motors, and … Read more
Michael Faraday discovered the phenomenon of electromagnetic induction in 1831 which was a major breakthrough and led to the invention of electric motor and generator. Faraday’s law of electromagnetic induction describes two phenomena: interaction between a conductor and a magnetic field, and the EMF generated by the magnetic field, which is widely known as Faraday’s … Read more
Heinrich Friedrich Emil Lenz was a Russian physicist, working at the University of St. Petersburg, Russia. He formulated Lenz’s law in 1834. This law predicts the direction of the current and the induced voltage in a coil held in a magnetic field. Lenz’s law – Statement The direction of an induced e.m.f. is always such … Read more
Resistors are the basic building blocks of a circuit. They are used in circuits as voltage dividers, current limits, termination for communication links, etc. It is important to know how to calculate their ohmic value by referring to the color codes of the resistor. Here is a simple and easy-to-use resistor color code calculator. Resistor … Read more
