Deepakkumar Yadav
Incandescent Lamp (a) Vacuum Lamps / Filament Lamps : These lamps can operate upto the temperature of 2000°C. The construction is shown in the Figure (A) The filaments used for this type of lamp are carbon, osmium, tantalum or tungsten. Tungsten is best of all. The filament materials have the properties: High melting point. Low … Read more
HRC Fuse (High Rupturing Capacity Fuse) HRC means “High Rupture Capacity”. The rupture capacity is the maximum current that can safely be interrupted by the fuse. A fuse is designed to melt and break the circuit if a preset “trip current” is exceeded. However, most fuses not designated HRC can only reliably break up to … Read more
Explain importance and purpose of earthing. To save human life from shock due to current leakage of installation. To protect large buildings from lightening fall. To isolate the faulty, section. This is achieved by providing path of leakage current through earthing system at this instant protective gearing operates. To protect installed machines fed from O.H. … Read more
Testing of Transformer Oil Question Q. Explain 1. Crackle 2. flash point 3. Acidity 4. Sludge test. Q. State the properties of good transformer oil. List out the various tests to be performed on transformer oil. Q. Explain how following test is carried for transformers : Testing of dielectric strength of transformer oil. Q. Explain … Read more
Differential Current Protection of Traction Circuits There are various schemes for the protection out of which differential current protection scheme for traction circuit is widely used. This protection is possible with the help of differential relays. These relays take a variety of forms depending on the equipment they protect. The differential relay is one that … Read more
Third Rail or Conductor Rail System Question Q. For conductor rail system used for current collection system: State its merit (any one) and demerit (any one). What is done to reduce the voltage drop at joints? Suitable system voltage. Answer Third rail or conductor rail system is a method of providing electrical power to electric … Read more
Isolator An isolator is a switch used to isolate a section of a circuit from any live conductor. It is also called as disconnector switch. They are not designed to break at load conditions. They are not designed to break any kind of fault current. They are design to operate only under no load conditions. In … Read more
Major Equipment’s of Electrical Substation Transformer, circuit breaker and interrupter are the major equipments in the traction substation. They are discussed below in detail. Transformer :- Transformer is the major component of traction substation. Normally, step down transformer is used to step the high voltage level from 220kV – 132kV to a working voltage level … Read more
What is Sag “is sag a necessity or evil” Discuss. The straight distance between the two poles gives the shortest distance. Therefore to minimize the length of conductor, one may stretch the conductor to make it straight. However if the conductor is stretched too much, beyond its safe value, then conductor may break due to … Read more
Construction of Electrical Underground Cable Components of Cable Conductors Insulation Metallic sheath Bedding Armouring (Mechanical protection) Serving (1) Conductors Conductors used for cables are generally made up of tinned copper or aluminium. To provide the sufficient flexibility conductors are used in stranded form. Cable may consists of one, two, three or four conductors depending upon the … Read more