Answer Posted / qamar

motor works on v/f=constant, if frequency is increased we
have to increase voltage for satisfactory opearation.

how we calculate the withstansing current capacity of wires&cables?

1485

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My question is whether bellow formula is correct to find bus size for 46kA for 0.5 second & what is RT in bellow formula. formula to calculate the size of busbar to withstand the thermal stresses due to currents with duration of 0.2 sec to 5 sec. Sp = RT( I x I x t) / K Where Sp – is the cross sectional area of bus bar in millimeters. I -    is the value of AC fault current. t -    is the operating time of disconnecting device in seconds. K –  is the factor depending on the material of the conductor, insulation and initial and final temperature. Value of ‘k’ for copper is 143.

1447

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how we provide neutral earth on synchronising panel as per electrical standards?

1590

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how the characterstics of control valve being done

1464

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Explain few advantages of electric traction system?

587

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What is earth system using on the floater TN-S or TT. Iam not sure and what ICCP

1241

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what happen as when voltage drop(or may decrease) ? in case of atomic base theory?

1542

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How eddy current generation support the idea of train braking?

1431

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What happen to generator if i have unbalanced load?

1648

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what is circuit recombiner and how it is different from circuit breaker

1372

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can the measured percentage error during calibration of single phase energy meter be negative?

1917

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# 4 hi friends i m from electrical branch and seeking for tech. + apti. both papers of hpcl plz get it available as soon as possible my email id is sumit_lig189@yahoo.co.in

1569

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any application of back emf

1615

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how can i reduce sparking without stepdowning the voltage

2081

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Mr. mohh sahid m not satisfied for ur answer to the que weather the size of transformer increases or decreases withchange in fr for more detail go to the answer given by me

1628

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