Answer / ss

there is chances of failure of ac suply but dc suply cant
fail because it is fed from batery bank.

Answer / maddoxx

in control and protection ckt very small current is require in relays ,cb etc .The panel is placed far from the work place.so if we use small ac current there may be chance of interference by communiation frquency and signaling it also produces noise which can too interfere in other sognalling freq. so dc current there is no frequency and we can increase the accuracy and sustain the strenth of signal coming to controlling panel.

Answer / vijay balu raskar

DC is constant & continuous source. For protection & control it is suitable. Also, having quick responce without disturbance & variation. In ac opposite of dc.

Answer / tahirwasim10

Protection of a system is very necessary factor which
require fast response during faults. For protection of a
power system the D.C used instead of A.C because there are
many problems in A.C ( quantities variation problems, slow
response problems etc).

why plc need seprate earthing?

2 Answers   ABB, Whirlpool,

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What is static frequency control used in gas turbines

1 Answers  

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why dc power can not be used in transformer?

33 Answers   GE, Sail,

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need help, please can someone tell me how can i calculate the main breaker and branches breakers to distribution panels (MDB) depending on the load ampere .. i really need it but can't find any site >>

3 Answers  

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How does the sensitive earth fault protection provided by cbct for motor can help in reducing the size of cable used to supply the motor?

1 Answers  

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What happen when increese more than 50HZ fequincy.

5 Answers  

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What is an 86-P or an 86-A trip

0 Answers  

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why neutral and earth should not be connected on 3 phase 440v/50c/s supply at consumer side. where as on 25kv/ac/50c/s railway traction substation neutral and earth will be connected and track at substation. and track will act as neutral and earth. Reasons for this is needed urgently

4 Answers  

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Dear sir, By which formula u can calculate for a particular kv line there is a range of mw.

0 Answers  

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What is the range of the stator resistance of 3 phase induction motor?

1 Answers  

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Why we are using Isolation Power Transformer inplace of commercial power transformer? What's the difference between them?

0 Answers   UPCL,

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why is the conservator tank painted white on the transformer

0 Answers   Bangladesh Bank,

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