Electrical4U 
A measurement system includes an input device (sensor) that senses the environment, a signal processing block that processes the sensor’s signal, and an output device that presents the signal in a readable form for humans or machines.The initial stage is input device which is mainly what we are going to discuss in this chapter. Sensor … Read more
Silica Gel Breather of Transformer Whenever an electrical power transformer is loaded, the temperature of the transformer insulating oil increases, consequently the volume of the oil is increased. As the volume of the oil is increased, the air above the oil level in conservator will come out. Again at low oil temperature; the volume of … Read more
Conservator Tank of a Transformer This is a cylindrical tank mounted on supporting structure on the roof the transformer main tank. The main function of conservator tank of transformer is to provide adequate space for expansion of oil inside the transformer. Function of Conservator Tank of a Transformer When the transformer is in use and … Read more
A power transformer is the most costly and crucial piece of equipment in an electrical substation. Therefore, it’s important to carry out various preventative maintenance activities to keep it performing well and extend its functional life. A power transformer requires various routine maintenance tasks including measurement and testing of different parameters of the transformer. There … Read more
In the early days, only conventional over-current relays were used for busbar protection. The goal was to ensure that faults in any feeder or transformer connected to the busbar did not affect the entire busbar system. However, the time settings of these relays were lengthy, causing delays in isolating faults on the busbar itself, which … Read more
Instruments that measure reactive power in a circuit are called varmeters. Reactive power in a circuit is calculated using the formula VIsinA.Here there is no need to give an explanation about the physical meaning of reactive power, as only a mathematical relation is sufficient. Measurement of reactive power is essential because if the reactive power … Read more
Various methods are used for measurement of three phase power in three phase circuits on the basis of number of wattmeters used. We have three methods to discuss: Let us discuss one by one each method in detail. Measurement of Three Phase Power by Three Wattmeters Method The circuit diagram is shown below-This method is … Read more
The Weston type frequency meter works on the principle that when current flows through two perpendicular coils, magnetic fields are produced, causing a magnetic needle to deflect towards the stronger magnetic field, indicating the frequency. Its construction is similar to the ferrodynamic type of frequency meter. The circuit diagram requires two coils, three inductors, and … Read more
Before introducing various types of power factor meters, it is essential to understand their importance. We cannot directly calculate power factor in an AC circuit by dividing power by the product of current and voltage from a wattmeter, ammeter and voltmeter because this method is inaccurate and prone to errors. Therefore, industrial applications require accurate … Read more
In a three phase system, the phases are conventionally labeled as RYB. A phase sequence indicator is a device that determines the order of these phases in a three-phase supply.When we apply a conventional RYB three-phase supply to an induction motor, the rotor rotates clockwise.Now what will happen to direction of rotation of rotor if … Read more