We all know about overhead transmission lines and underground cable for power transmission at high voltage. ABB recently has successfully commissioned 1000 KV gas insulated transmission line(GIL) through a tunnel…
You all know, how important a trip circuit is for a circuit breaker. if for instance, following problems will come in trip circuit, breaker will not trip when required or…
You all know, What we will do to improve system power factor ..install the capacitors. Consider below case: Suppose you have a electric system on which 10 nos LT motors(…
Have you seen this (kindly see below picture) ? This is a outdoor 11000/440 volt substation on double pole structure. Why you need this ? Obviously you need Low voltage…
MCB(Miniature Circuit Breaker)Credit: ABB See above picture, have you seen this type of thing in your home ??? This is MCB .. in the above picture, four nos MCB are…
Buchholz relay in transformers -Construction, Working and Diagram: General : This relay was invented by Max Buchholz in 1931. it is used in those oil filled transformer having conservators. look…
As you all know, transformer contains windings which carry electric current and electric current in the transformer winding produce heat. This heat is taken up by oil in transformer tank…
Before we go for comparing both types of Circuit breaker, just see pictures of both i.e. live tank and dead tank SF6 circuit breaker. How these breakers looks from outside.…
LM79, LM70, LM80 are test procedure developed and approved by illumnating Society of North America (IESNA) on LED lights. LM80 This test LM80 gives the age or lifetime of LED…
Luminous flux of luminarie (Light fitting or bulb) Luminous flux is total light output emitted by luminarie. It is denoted by (?) or lumen or lm. Light emitted by a…
Potentiometer..when you hear the word ..what comes in your mind ..yes .. potential and meter ..means the meter that measures potential ..yes it is used to measure the potential as…
This is BJT , How it looks like Construction of BJT(Bipolar junction Transistor) Bipolar junction Transistor is a semiconductor device means it is made up of semiconductor materials i.e. silicon…
It has 3 terminal device just like BJT(bipolar junction transistor). It is also a semiconductor device. FET can be turned on and off by electric field. Two types of FET:…
Induction Wattmeter is used to measure power in AC Circuits. We all know Power = VI Cos(Theta) where V is the voltage , I is the Current and Theta is…
This instrument is similar to PMMC(Permanent Magnet Moving Coil) Instruments except in place of permannet magnets , there is a coil . Construction: There is a coil which is divided…
Construction & Working : simply in brief , there is a coil which is free to move and is surrounded by powerfull magnets. Now we dicuss in detail .. There…
As the name suggests , there is iron piece in these instruments ..the movement of this iron piece gives the necessary reading. These instruments are of two types i.e. attraction…
1. Drift velocity of electrons Electrons move in the conductor randomly when no voltage applied to it and so average velocity is zero. When a voltage applied to the conductor,…
Now it is not used anywhere in the design of integrated circuits. In this type of ICs , only transistors and resistors are used. The RTL circuits basically performs the…
Pic: A transparent box containing silica gel crystals You have seen this type of transparent box with blue crystals like substance inside. These blue crystals are silica gel. So what…
Before we start, lets go back to CT basics, what a CT does , obviously a 2000/1 amp delivers 1 amp at secondary when 2000 amp is flowing or 0.5…
There are many terms we come across when we read about current transformer(CT) and Potential transformer(PT) or voltage transformer(VT) /capacitive voltage transformer( CVT). below are meaning of these terms. CT/PT…
SF6 gas is an inert gas with dielectric strength and arc-extinguishing qualities. In SF6 breakers, the rate of rise of dielectric strength is very high and the time constant is…
The capacitive-coupled potential transformer (CCPT) or Capacitive Voltage Transformer is a Voltage Transformer with a capacitive circuit as shown in the figure below. The two Capacitor C1 and C2 here…
When a oil immersed transformer is subjected to internal faults, than due to short circuit flowing through transformer windings, the temperature of windings rises, this give rise to rise in…
Capability curves are a plot of apparent power capability (MVA), at rated voltage, using active power (MW) and reactive power (MVAR) as the two principle axis. Circumferences drawn with their…
Performance curves means when motor performance is shown as a graph from starting of the motor to running. Generally variation of following parameters are noted at various loading of the…
Both crawling and cogging effect is only observed in squirrel cage induction motor as in wound rotor inductor motor, this effect is not observed as toque is very large. Crawling:…
Circuit breakers are installed indoor and outdoor. indoor in the panels , and outdoor in the panels or standalone. Circuit breaker can be air circuit breaker(ACB) or SF6 circuit breaker…
Synchronous condensor is just a synchronous motor without any load , but with over excitation. Generally it is used in receiving grid electric substations to improve power factor. The synchronous…
