Answer / krishnappan

in switchyard first our earth switch should be open.
after that close the bus isolator,then line isolator.
finally close the circuit breaker

Answer / sandeep

in case of maintainance first open the circuit breaker then
open the isolator then close the earthing switch
and while charging the line do exact reverse i.e. open
earthing switch first then close isolator then finally
close circuit breaker.

why does spark appears when we swith on the light

1 Answers  

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where rlc series ckt used?

0 Answers   ABB,

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What is the fullform of NS fuse

2 Answers   Google, JAL International,

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why do we generate sinusoidal ac?can we generate some other waveforms by alternators?

11 Answers   Siemens,

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what happens if dc supply is given and the remedies for it.

0 Answers  

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When we synchronize the Generator BKR with TIE BKR then Gen BKR is hold but TIE BKR is Tripped on Non directional over current but when TIE BKR is Syn. with Gen. BKR then no fault occur so what is the problem

1 Answers   ABB,

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1 Answers  

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Why line VTG = √3 phase VTG in star? How?

0 Answers   Endurance International Group, Infosys,

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What is a fuse? How does it work? What are materials used?

0 Answers  

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Hi, I've just got into my electrical engineering course and I need some help with a question of mine here. During a site visit, we were shown a main LT panel which has switchgears, ammeters and different kinds of relays and the distribution network from that panel. In the main LT panel I've noted down the current readings as Ir - 163A, Iy - 150A and Ib - 147A. The Line to Line voltage is 415 V at 50 Hz and Line to Neutral voltage is 230V at 50 Hz. From the above details, how would I calculate the kVA rating of transformer? The primary side voltage of the transformer is 11 kV and the secondary side voltage is 415V and the frequency is 50 Hz.

2 Answers  

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when we given 3 phase supply to ups system, but out put comes with 3 phase + neutral how it possible? pls explain.

3 Answers   Enzen, Juniper Networks,

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What is the reason of using bus-bars on the secondary on the LT transformers?

2 Answers  

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