WHAT IS DEGREE OF COMPOUNDING IN D.C MACHINE MEANS? HOW TO READ THE OPERATING CHART FOR ANY ELECTRICAL MACHINES?

0 Answers   Coal India, Ghana Grid Company,

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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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what is control supply rating of a machine

0 Answers  

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Why Ac Systems Are Preferred Over Dc Systems?

0 Answers   ABB,

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Where the Dry type tranformers are used.

5 Answers  

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How short circuit MVA(Fault MVA) in a power system calculated for calculating number of earth plates ?

0 Answers   NA,

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Draw a SLD for main panel for school having connected load of 1200kw and emergency generator 200kw.also show the increase of additional load of chiller 225kw in the lv panel indicating meter postion size of transformer ,cables and capacitor bank.

0 Answers  

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What is the purpose of Vector Group in transformer?

1 Answers   Andritz, ThyssenKrupp,

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Differentiate between kirchhoff’s first law and kirchhoff’s second law?

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How Size of Busbar is determined for a particular load.

2 Answers  

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what is surge voltage and surge current?

2 Answers   MES,

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how to select the mpcbs and contactor for 3 phase 30 hp star delta motors.for plc control.and tell me the calaculation for future use.

0 Answers  

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