When an electrical current traverses the human body, the nervous system endures an electric shock. The severity of this shock predominantly hinges on three key factors: the magnitude of the current, the pathway the current follows through the body, and the duration of contact. In the most severe instances, the shock disrupts the normal functioning of the heart and lungs, potentially leading to unconsciousness or even death.It is generally accepted that currents below 5 milliamperes (mA) pose min

Definition: The maximum demand indicator is used to measure the maximum amount of power consumed by a consumer within a specific time interval. It is designed to measure base and peak loads, but it cannot measure sudden short - circuit currents or the high starting currents of motors. Its purpose is to record power consumption over specific periods.The maximum demand indicators are categorized into four types:Recording demand indicatorAverage demand indicatorThermal type maximum demand indicator

An automatic voltage regulator is employed to regulate voltage, converting fluctuating voltages into a constant one. Voltage fluctuations mainly stem from variations in the load on the supply system. Such voltage variations can damage the equipment within the power system. These fluctuations can be mitigated by installing voltage - control equipment at various locations, such as near transformers, generators, and feeders. Multiple voltage regulators are often placed throughout the power system t

Types of Static Voltage RegulatorThe static voltage regulator is superior to electromechanical regulators in respect of the accuracy of control, response, reliability and maintenance. The static voltage regulator is mainly classified into two types. They are;Servo Type Voltage RegulatorMagnetic Amplifier RegulatorThe types of static voltage regulator are described below in details;Servo Type Voltage RegulatorThe main feature of the servo type voltage regulator is the use of the amplidyne. The am

When the current-carrying contacts of a circuit breaker separate, an arc forms and persists briefly after contact separation. This arc is hazardous due to the heat energy it generates, which can produce explosive forces.A circuit breaker must extinguish the arc without damaging equipment or endangering personnel. The arc significantly influences the breaker’s performance. Interrupting aDC arcis inherently more challenging than anAC arc. In an AC arc, the current naturally reaches zero duri

In an air break circuit breaker, the arc is initiated and extinguished in substantially static air as the arc moves. These breakers are used for low voltages, generally up to 15 kV, with rupturing capacities of 500 MVA. As an arc-quenching medium, air circuit breakers offer several advantages over oil, including:Elimination of risks and maintenance associated with oil use.Absence of mechanical stress caused by gas pressure and oil movement.Elimination of costs from regular oil replacement due to

A fuse is a device employed in electrical circuits to protect electrical equipment against overloads and short circuits. It is the simplest and most cost-effective component for interrupting an electrical circuit when exposed to short-circuit currents or excessive overloads.Fuses are used for overload or short-circuit protection in high-voltage systems of up to 66 kV and low-voltage systems of up to 400 V. In certain applications, their use is limited to scenarios where their performance charact

A fuse is a current-interrupting device that breaks or opens a circuit by melting its element when the current in the circuit surpasses a specific value. Fuses are predominantly categorized into two types: high-voltage fuses and low-voltage fuses. Low-voltage fuses can be further divided into two subtypes: semi-enclosed or rewirable fuses, and fully enclosed cartridge fuses.Rewirable FusesRewirable fuses, commonly referred to as kit-kat fuses, are widely utilized in residential wiring and small-

High Rupturing Capacity (HRC) Fuses: Design, Operation, and ApplicationsCore FunctionalityHRC fuses are engineered to safely conduct short-circuit or fault currents for a specified duration. If the fault is cleared within this timeframe, the fuse element remains intact; otherwise, it melts to interrupt the circuit. Encased in an airtight container, the element is shielded from environmental factors while enabling efficient arc quenching.Inverse Time CharacteristicHRC fuses exhibit a criticalinve

Definition and Principle of Impedance Relay (Distance Relay)An impedance relay, also known as a distance relay, is a voltage-controlled protective device whose operation depends on the electrical distance (impedance) between the fault point and the relay’s installation position. It functions by measuring the impedance of the faulty section and comparing it with a pre-set threshold.Working MechanismMeasurement and Comparison: The relay continuously monitors line voltage (via potential trans