Answer / ashutosh jha

An electric generator or electric motor consists of a rotor spinning in a magnetic field. The magnetic field may be produced by permanent magnets or by field coils. In the case of a machine with field coils, a current must flow in the coils to generate the field, otherwise no power is transferred to or from the rotor.

What is the difference between UPS & inverter ? which UPS is better and whos got the edge ? what is the difference between & inverter ? which UPS is better and whos got the edge 12 V , 24 V , 36 V etc what are the advantages of 12 V, 24 V , 36 V etc and what are the disadvantages of 12 V, 24 V, 36 V etc thanks

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how netral CT is selected (including its details specification)

8 Answers   ABB, ABC, dbpl, Mecon, Shree Engineering, Tapasya Transformers,

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WHY THE COLOUR OF TRANSFORMER IS GREY ?

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who invented electricity?

20 Answers   L&T,

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An 8 pole, 50 Hz, 3-phase IM is loaded to a poing where pull out torque will occur. The rotor resistance per phase is 0.3 ohm and motor stalls at 650 rpm. The slip when motor stalls is A 1 B 0 C 13.33% D 10.33%

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the site measured knee point voltage of protection class CTs should be greater than rated knee point voltage? what about meetering class CTs. Should it be below the rated knee point voltage?

0 Answers  

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What is the two pole structure?

0 Answers   Foxconn,

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is there any lightning by passer is arranged in ship like buildings?

0 Answers  

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check list of maintenance of transformer?

11 Answers   ABC, Cosmos, EPRON, Essar, Godrej, Hescom, Infosys, KPTCL, TCS,

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WHATS THE DIFFERENCE IN USING THE 125% AND THE 250% FACTOR OF SAFETY IN CALCULATING CIRCUIT BREAKERS CAPACITY IN MOTOR APPLICATION??

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Any one can explain if there is any harm from humming noise heard from air circuit breaker : we have 415 switch board having two incomers from transformers 3.3KV/415V , when bus coupler closed, and open one ACB incomer to work in one of the transformers, the current started hunting around 50 Amps, and heard humming noise from the air circuit breaker, although the load current was only 1200 amps while the ACB capacity is 2500 Amps, and the transformer 1600 KVA. The same didn't happen when taken the other transformer offline. Why this humming noise and current fluctuation? is there any implication or danger, bearing in mind that we just returned everything back to normal and stopped the maintenance of the transformer. Shall we go ahead and ignore this noise?

6 Answers  

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in cable joints procedure what electrical problems have been solved out ?

1 Answers  

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