Answer / pawar shyamkant sitaram

It depends upon the system power frequency voltage before
the fault appearing on first pole to the volage appearing
across the heathy poles after clearing the fault. The value
of first pole to clear factor is mainly decided by the
sytem grounding & ratio of zero seq.impdence to positive
sequence impedance.

Answer / ajit

iF THE THREE PHASE FAULT NOT INVOLVING THE EARTH THE
VOLTAGE ACROSS THE CIRCUIT BREAKERPOLE. FIRST POLE CLEAR
105 TIMES THE PHASE VOLTAGE IN 3 PHASE AC CIRCUIT BREAKER
ARC EXTINTION IN THE THREE POLE IS NOT SIMULTENEOUSLY AS
CURRENT IN THREE PGASES ARE MUTUALLY 120 DEGREE OUT OF
PHASE. HENCE THE POWER FREQUENCY RECOVERY VOLTQAGE OF THREE
PHASE IN WHICH ARC GETS EXTINGUISHED FIRST IS ABOUT 105
TIMES OF PHASE VOLTAGE.FIRST POLE TO CLEARE FACTOR IS THE
RATIO OF VOLTAGE BETWEEN HEALTHY PHASE TO FAULTY PHASE TO
NORMAL PHASE VOLTAGE.

Answer / sudipt jena

Actually the voltage rise due to TRV is 1.2-1.5 times that of phase voltage.And this is happened due to the 120 degree phase shift of 3 phase current leading to interrupt of current at different instants.

What is vacuum circuit breaker.define with cause and where be use it device?

0 Answers  

---

Hi, This is Laila. I am selected for syndicate bank interview. Could you please share your views and the questions asked if you have faced the interview My email id is laila_honey09@yahoo.com Please send as fast as u can.Thank You Thanks... Laila.

0 Answers   RRB,

---

in power generator normaly voltagr betwween esth to neutral is 0 but my work place generator show the volatge is 60v any body know why? thanks

0 Answers  

---

what is the difference between current voltage transformer and current transformer and where it is used?

2 Answers  

---

WHY THE DIMENSION OF TWO SAME RATED MACHINE IS DIFFERENT ?

0 Answers  

---

In Panels Main Incomer considered should be TPN or FP?

2 Answers  

---

why trip circuit supervision is taking through breaker contact? what happen if takendirectly?

2 Answers   GE,

---

what is frequency response?

0 Answers  

---

what is lightning arester?generaly which type of used in industeries? why its used?

7 Answers   Essar,

---

why odd hormonics only will effect the power system.why not even hormonics

2 Answers  

---

how to calculate regulation constants for over head lines? and what are the regulation constant for raccoon conductor at different voltage level and different P.F?

0 Answers  

---

What is the one main difference between ups & inverter ? And electrical engineering & electronics engineering ?

0 Answers  

---