Tricky but Easy Electrical Engineering!
Cable capacitance is the formation of capacitance between the charged core or conductor and the earthed lead sheath. Therefore it is quite important to have an idea of how the cable capacitance varies or the factors affecting its value. Calculation of Cable Capacitance A single core cable is similar to two long co-axial cylinders having … Read more
What is Current Chopping? Current Chopping in circuit breaker is defined as a phenomena in which current is forcibly interrupted before the natural current zero. Current Chopping is mainly observed in Vacuum Circuit Breaker and Air Blast Circuit Breaker. There is no such phenomena in Oil Circuit Breaker. Current chopping is predominant while switching Shunt … Read more
Resistance Switching in Circuit Breaker refers to a method adopted for dampening the over voltage transients due to current chopping, capacitive current breaking etc. In this method, a shunt resistance is connected across the contacts of circuit breaker. How does Resistance Switching Work? Let us consider a circuit and connect a shunt resistance R across … Read more
In Sulpher Hexafluoride or SF6 Circuit Breaker, sulpher hexafluoride (SF6) gas is used as an insulating and arc quenching medium. SF6 gas has many superior properties which makes it perfect for arc quenching.Sulpher Hexafluoride or SF6 Circuit Breaker is most popular and widely used breaker. This type of breaker is mostly used for EHV systems like … Read more
Symmetrical Fault in Power System refers to kind of fault which leads to short circuit of three phases. This may be either short circuit of three phases or three phases to ground fault. In symmetrical fault, fault currents in phases are symmetrical in the sense that their magnitudes are equal and they are equally displaced … Read more
Electrodynamic type instrument is used for the measurement of AC and DC quantities unlike PMMC instrument which can only be used for the measurement of DC quantity. This type of instrument is known as Elctrodynamometer type instrument. Construction of Electrodynamic Type Instrument An electrodynamic type instrument consists of Two Fixed Coil, a Moving Coil, Control … Read more
Electrodynamometer Instruments are widely used as an ammeter, voltmeter and wattmeter. This instrument can measure AC as well as DC quantities. This means that the torque in electrodynamometer instruments must have a finite value and unidirectional for AC and DC quantity unlike PMMC instruments. In this post we will be discussing the torque equation in … Read more
A VRLA battery or Valve Regulated Lead Acid Battery is commonly known as a sealed battery or maintenance free battery. This is one type of Lead acid rechargeable battery. Due to the construction of VRLA Battery, it do not require ventilation and can be mounted in any orientation and do not require constant maintenance. The … Read more
What is Load Factor? Load factor is defined as the ratio of average load to the maximum demand for a given period of time. Thus mathematically, load factor may be written as Load Factor = Average Load / Maximum Demand Load factor is generally calculated for a day, month or year. If we calculate the … Read more
A storage battery can have a relatively long life. Some lead acid batteries may operate efficiently for around 20 years or more, provided all conditions of operation are ideal. Such conditions are not usually obtainable. The end of battery life may result from either loss of active material, lack of contact of active material with … Read more