Answer / omar aziz

Every electrical equipment installed in a power system has
an I2t rating. Eg(20kA for 1sec) This indicates the maximum
permissible energy that the equipment can withstand before
blowing into bits. Protection co ordination must ensure
that this damagiong curve is always protected by the
protection system. This is Energy based coordination.

Time based coordinaation is when no energy basis are
required but time selection is picked for personnel safety
reasons and not equipment damage reasons

cb used in railway applications is?

2 Answers   NTPC,

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i am an maintenance engineer. one distribution board have 5 feeder. recently its ELR trips frequently, but it take some times after trip( 10min,20min..)but 3 feeder no load. two feeder only loaded. i checked one feeder IR value all values are above 50Mohm.but B phase to Earth is only 9Mohm.any problem about low value

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what is means of CLASS in current transformer name plate?

3 Answers  

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What is differential relay ? where it can be used?

1 Answers   Scope International,

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how we can classify the circuit braker???????

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16 Answers  

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what are the protections used in power transformers of 5 mva and above

2 Answers   ESRI,

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what is relation between HP & BHP

3 Answers   Usha Martin,

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why there is a 2 slits in three pin's earthing pin?

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2 Answers   Bell, TCS,

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HOE WE CAN IMPROOVE BY USE OF CAPACITOR

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in underground cables, we have a grading method called 'capacitance grading' why is it called 'capacotance grading' although we do not use any capacitor in it?

1 Answers  

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