How to Disable Full DR Alarm in Numerical Relay?

These days mostly Numerical Relays are used for protection purpose instead of conventional Electromechanical Relays. In fact, Numerical Relays offer a variety of protection as well as trouble shooting features. A single Numerical Relay can provide many protection unlike conventional Electromechanical Relays. A single Numerical Relay can have provision of Overcurrent, Earth Fault, Over-voltage protection … Read more How to Disable Full DR Alarm in Numerical Relay?

Vacuum Circuit Breaker- Construction and Working

Vacuum Circuit Breaker Vacuum Circuit Breaker (VCB) is one where vacuum of the order of 10-6 to 10-10 torr is used as an arc quenching medium. 1 torr is equivalent to a pressure represented by a barometric head of 1 mm mercury. Vacuum Circuit Breaker is used for low and medium voltage applications. Construction of … Read more Vacuum Circuit Breaker- Construction and Working

Transient Recovery Voltage (TRV)

“The Transient Recovery Voltage refers to the voltage across the pole immediately after arc extinction. Such voltage has a power-frequency component plus an oscillatory transient component.” In alternating current circuit breakers, the current interruption takes place invariably at the natural zero of the current wave. After a current zero, the arc gets extinguished if the … Read more Transient Recovery Voltage (TRV)

Causes of Insulation Deterioration

Heat is the prime cause which leads to electrical insulation deterioration. Some possible causes of heat generation in the electrical insulation are as follows: Heat is generated in the electrically stressed insulation, due to dielectric loss and conduction currents. Heat is imparted to insulation by the neighboring current carrying parts. Now if we look at … Read more Causes of Insulation Deterioration

3 Deleterious Effects of Transient Recovery Voltage

Transient Recovery Voltage (TRV) is the voltage appearing across the contacts of circuit breaker after a switching action. Typically, every transient TRV has high amplitude and high frequency. In this post we will be disusing the Effects of Transient Recovery Voltage . For detail on Transient Recovery voltage, read Transient Recovery Voltage (TRV) Transient Recovery Voltage … Read more 3 Deleterious Effects of Transient Recovery Voltage

Theory of Arcing Ground-Ungrounded System

Ungrounded System is one where the neutral is not connected to earth. Thus, neutral of ungrounded system is isolated. Arcing Ground is an electrical phenomenon in which the voltage of faulty phase fluctuates due to capacitive charging current. This arcing ground phenomenon is prevalent in three phase ungrounded neutral system. Don’t worry I will explain … Read more Theory of Arcing Ground-Ungrounded System

Working Principle of Petersen Coil

To better understand the working principle and need of Petersen Coil, let us have a look at the arcing ground phenomenon. We know that arcing ground phenomenon is observed in ungrounded 3 phase system. During arcing ground the voltage of healthy phase rises from phase voltage to line voltage i.e. it becomes √3Vph. Also, arcing … Read more Working Principle of Petersen Coil

Voltage Regulation and Efficiency of Transmission Line

We know that, Electric Power is transmitted using three phase transmission system due to its own advantages. But for any system it is very important to define some parameters to evaluate the performance. Therefore, there must be some parameters which define the performance of transmission line. Yes, there are two parameters namely, Voltage Regulation and … Read more Voltage Regulation and Efficiency of Transmission Line