Answer / k.prakashchandra

The relay measures rate of drop in frequency ,which is due sudden increase in load or decrease in generating capacity . When df/dt exceeds the set value ,the relay closes the trip circuit.

WHATS THE DIFFERENCE IN USING THE 125% AND THE 250% FACTOR OF SAFETY IN CALCULATING CIRCUIT BREAKERS CAPACITY IN MOTOR APPLICATION??

0 Answers  

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While connecting the flood light plug on to the 415 V distribution panel,there was spark and the cable got burnt. Three ignitors of the flood light also burnt of. The lamps are of 400 W (total 6 lamps) connected through 1.5 mm2 cable. The plug was immediately removed from the circuit. There was a 30 mA RCD connected and a 250 A MCCB; however both did not trip. What could be the possible reasons for the circuit devices not to trip?Can someone assist please. Additional info if needed can be provided.

2 Answers  

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how much speed will trawiling current

3 Answers   TCS,

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which type of capacitor store high amount of energy for long time ? ( polarized or unpolarized )

1 Answers  

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what is the disadvantage of leading power factor...why can't we use it (pf=0) for a long period of time?

10 Answers   Appco, snsce,

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We use ungrounded DC system (220V/110V) for control and protection system in substations etc. Suppose we have long 2 core DC cables running from our DCDB in control room to the load (length of around 2 to 3 km). Do we need to protect these long DC cables from earth leakages or not? If yes how?

5 Answers   Siemens,

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Difference in load break switch, isolator and circuit breaker.

1 Answers   KSEB, L&T, Siemens,

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11kV capacitor bank of rating 2.4KVAR, is charged with protective relays of only over current & Earth fault &.......without Over Voltage, Under Voltage & Neutral Displacement Relay. Is it advisable??

0 Answers  

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how to reduce the magnetizing current in distribution transformers

1 Answers  

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What is the BS(British Standard)code for 11kv motor

1 Answers  

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what is the working principle of electrical motors?

4 Answers  

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what is STUB protection in tranmission system and switch yard area?

9 Answers   KSEB, Power Grid,

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