An 11kv system consisting of an underground cable to a sub station about 300 meters away was shut down for about 10 hrs. On energising, it tripped off on earth fault about 10---20 mins later 6 times but since than it is not tripping.its already 3 weeks now. The SPAJ was found to be fine. what could be the cause.No test had been done to determine the cause of the trippings till now because of demand.

2 Answers  

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If rotor works in clock wise what happens

0 Answers  

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What is Form factor?

2 Answers   NTPC,

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The slip during plugging operation is given by= A 1-s B 2+s C 1+s D 2-s

0 Answers  

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difference between crane drive and line drive.

0 Answers  

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what is dc mator?types of dc motor?losses in dc motor?what is the mechanical,electrical and commercial efficiency of a dc motor?

0 Answers  

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In ACS 1000 drive we used 12 pulse convertor.Why dont used 6 pulse or 3 pulse convetor

1 Answers  

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tell me some type of questions throught which i can prepare for exam and do my best

0 Answers   Jindal,

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Whta is earthing?What is the optimum value of Earth Pit?

2 Answers   Bharti,

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how can we detect that which is receiving side and which is sendind end of a trnasmmison line by just seiing it?i.e its which end is coming from genertaing and distribution side?

5 Answers  

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can we check the resistance of earthing electrode while it is connected with the neutral of UPS system

3 Answers  

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tell me the various standerd of CT ratio

1 Answers   ICA,

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