RATING OF LIGHTENING ARRESTER FOR 11 KV LINE IS 9 KV BUT WE
KNOW THAT LIGHTENING ARRESTER IS USED FOR OVER VOLTAGE
PROTECTION SO WHY NOT THE RATING OF LIGHTENING ARRESTER BE
MORE THAN 11KV ???????????????//

Answers were Sorted based on User's Feedback



RATING OF LIGHTENING ARRESTER FOR 11 KV LINE IS 9 KV BUT WE KNOW THAT LIGHTENING ARRESTER IS USED ..

Answer / elangovan t

Lightning arrester is to protect the system from any high
voltages such as lightning.
If the system voltage is 11kv, then the phase voltage will
be 11/sqrt(3)=6.35kv. It means the RMS voltage of the phase.
The maximum voltage or the peak voltage across the arrester
and earth will be 6.35*sqrt(2)=8.98kv.i.e 9kv.
Therefore, for 11kv line it is rated for 9kv.

Is This Answer Correct ?    135 Yes 10 No

RATING OF LIGHTENING ARRESTER FOR 11 KV LINE IS 9 KV BUT WE KNOW THAT LIGHTENING ARRESTER IS USED ..

Answer / h r jadhav

when we use ac line having system line voltage 11kv,in
this case phase voltage [phase to neutral which is earthed}
is 6.351 kv. lightening arrester is connected between phase
and neutral. lightening arester are nothing but the voltage
dependant resistors which act as insulator up to not only
the phase volatage ie 6.351 kv rms but ac peak voltage
reaches to 6.351 rms x root of 2 ie 1.414=8.98 kv. for
normal operation of system. thus the L A s are rated for
normal voltages 9 kv and discharge current generaly 10 kamp.
when ever voltage surges occures due to lightenig or either
by system abnormabilty,L A becomes for a instance as a
conductor provides path to surge voltages and prevents
failure of insulation leveles of equipment of system

Is This Answer Correct ?    32 Yes 5 No

RATING OF LIGHTENING ARRESTER FOR 11 KV LINE IS 9 KV BUT WE KNOW THAT LIGHTENING ARRESTER IS USED ..

Answer / nageshwar

FOR A 11KV LINE LINE TO GROUND VOLTAGE IS 11KV/SQRT(3). IT
GIVES OF THE ORDER OF 6KV ONLY. AS ARRESTER IS USED FOR
LINE TO GROUND TO DISCHARGE THE FAULT CURRENT TO GROUND ITS
RATING SHOULD BE MORE THAN 6KV. GENERALLY WE USE 9KV.

Is This Answer Correct ?    32 Yes 16 No

RATING OF LIGHTENING ARRESTER FOR 11 KV LINE IS 9 KV BUT WE KNOW THAT LIGHTENING ARRESTER IS USED ..

Answer / shirish

11kv is line voltage,but we put the lighting arrester in
phase so phase voltage of 11kv line is 6.351kv,now we can
not put rating of lighting arrester to 6.351kv because it is
normal phase voltage,so we put it 1.414(square root of
2)times more than phase voltage 6.6kv means 9kv.

Is This Answer Correct ?    13 Yes 4 No

RATING OF LIGHTENING ARRESTER FOR 11 KV LINE IS 9 KV BUT WE KNOW THAT LIGHTENING ARRESTER IS USED ..

Answer / gunasekaran

for solid grounding maximum voltage build up at earth faul
condition it self is not more than 80% of line voltage so
11*.8=8.8KV so we r using 9KV

Is This Answer Correct ?    8 Yes 9 No

Post New Answer

More Electrical Engineering Interview Questions

how does a current carrying conductor posess a magnetic field. what is the reason for the production of electro magnetic field around the conductor

2 Answers   Vizag Steel,


if dc motor can operate by ac supply ? if its possible means how ?

2 Answers  


How the current flows in dc circuit?

3 Answers  


where can i get the previous years question papers for APGENCO exam.

0 Answers  


Hi, what is 100 % stator earth fault protection and how it can be achieve by 3rd harmonics and low frequency injection principle ?

1 Answers  






what is LUX?

4 Answers   NTPC,


What is the use of core in the transformer?

19 Answers  


what is load despatching

0 Answers   NTPC,


what is the advantages og idmt relay over magnetic relay??

0 Answers   Bhel,


How to select the different contactors ( starter combination) for different AC motors? what about fuse cappacity 4 different motors too?

2 Answers   Equate,


How does "OUT OF STEP" relay ,for Synchronous motor protection, work?

0 Answers  


DIFFERENCE BETWEEN NORMAL TRAFO AND THRISTER TRAFO?

0 Answers   Essar, MahaGenco,


Categories
  • Civil Engineering Interview Questions Civil Engineering (5084)
  • Mechanical Engineering Interview Questions Mechanical Engineering (4451)
  • Electrical Engineering Interview Questions Electrical Engineering (16631)
  • Electronics Communications Interview Questions Electronics Communications (3918)
  • Chemical Engineering Interview Questions Chemical Engineering (1094)
  • Aeronautical Engineering Interview Questions Aeronautical Engineering (239)
  • Bio Engineering Interview Questions Bio Engineering (96)
  • Metallurgy Interview Questions Metallurgy (361)
  • Industrial Engineering Interview Questions Industrial Engineering (259)
  • Instrumentation Interview Questions Instrumentation (3014)
  • Automobile Engineering Interview Questions Automobile Engineering (332)
  • Mechatronics Engineering Interview Questions Mechatronics Engineering (97)
  • Marine Engineering Interview Questions Marine Engineering (124)
  • Power Plant Engineering Interview Questions Power Plant Engineering (172)
  • Textile Engineering Interview Questions Textile Engineering (575)
  • Production Engineering Interview Questions Production Engineering (25)
  • Satellite Systems Engineering Interview Questions Satellite Systems Engineering (106)
  • Engineering AllOther Interview Questions Engineering AllOther (1379)