Electrical FuseIn the normal working condition of the electrical network, the current flowing through the network is within the rated limit. If a fault occurs in the network mainly phase to phase short circuit fault or phase to ground fault, the network current crosses the rated limits.This high current may have a very high thermal effect which will cause permanent damage to the valuable pieces of equipment connected to the electrical network. So this high fault current should be interrupted as

Earth Leakage Circuit Breaker or ELCBAn Earth-leakage circuit breaker (ELCB) is a safety device used in electrical installations (both residential and commercial) with high Earth impedance to prevent electric shocks. It detects small stray voltages on the metal enclosures of electrical equipment, and interrupts the circuit if a dangerous voltage is detected.ELCBs help detect current leaks and insulation failures in the electrical circuits that would cause electrical shocks to anyone coming into

What is MCB?A Miniature Circuit Breaker (MCB) is an automatically operated electrical switch used to protect low voltage electrical circuits from damage caused by excess current from an overload or short circuit. MCBs are typically rated up to a current up to 125 A, do not have adjustable trip characteristics, and can be thermal or thermal-magnetic in operation.Fuse vs MCBNowadays miniature circuit breakers (MCBs) are much more commonly used in low voltage electrical networks instead of fuses. T

Dielectric materials are basically basic and pure electrical insulators. By applying a sensible electrical field, the dielectric gases can be polarised. Vacuum, Solids, Liquids and Gases can be a dielectric material. A dielectric gas is also called as an insulating gas. It is a dielectric material in gaseous state which can prevent electrical discharge. Dry air, Sulphur hexafluoride (SF6) etc are the examples of gaseous dielectric materials.Gaseous dielectrics are not practically free of electri

We often come across a situation where we want to switch on the electrical load by pressing some buttons on a computer program. Consider an example, where you are sitting in a power plant and you want to switch on a circuit breaker remotely. Controlling circuit breakers from a remote location can be achieved by using Microcontroller. We’ll discuss how to make a Remote Control Circuit Breaker Using a Microcontroller.For this remote-controlled circuit breaker we will need: Microcontroller (such as

When there is a short circuit fault in the electrical system, a huge short circuit current flows through the system including the circuit breaker (CB) contacts, unless the fault is cleared by tripping the CB. When the short circuit current flows through the CB, the different current carrying parts of the circuit breaker are subjected to huge mechanical and thermal stresses.If the conducting parts of the CB do not have sufficient cross-sectional area, there may be a chance of dangerously high tem

The primary function of an electrical circuit breaker is to provide opening and closing of the current carrying contacts. Although it is seems to be very simple. But we should remember, that, one circuit breaker remains at its closed position for maximum period of its life span. Very occasionally it is required to operate a circuit breaker for opening and closing its contacts.Hence circuit breaker operation must be very reliable without any delay or sluggishness. For achieving this reliability t

Various routine tests are performed for ensuring the quality, performance of a circuit breaker and these are Power frequency over voltage withstand test Dielectric test on auxiliary circuit and control circuit Measurement of resistanceof main circuit or contact resistance test Tightness test orSF6 gasleakage test Design and visual checks Mechanical operation tests.Let us discuss them one by one.Power Frequency Over Voltage Withstand TestThe power system may experience different temporary power o

The rating of a circuit breaker includes: Rated short circuit breaking current. Rated short circuit making current. Rated operating sequence of circuit breaker. Rated short time current.Short Circuit Breaking Current of Circuit BreakerThis is the maximum short circuit current which a circuit breaker (CB) can withstand before it, finally cleared by opening its contacts.When a short circuit flows through a circuit breaker, there would be thermal and mechanical stresses in the current carrying part

The electrical power demand is rising rapidly. Now days, huge quantity of electrical power is necessary to transmit from one place to other for fulfilling this rising power demand. Bulk power transmission can be most efficiently done through high voltage electrical power transmission system. Hence, high voltage system becomes most essential requirement for power transmission. The equipments used in these high voltage transmission system, should be capable of withstanding this high voltage stress