WE are using a 63A MCCB(SIEMENS MAKE) for one of the feeder
in LV substation panel.It is supplying to a lighting & power
socket DB.Settings in the MCCB is Ir = 63 * 1 , Isd = 8
times of Ir , tsd = 0.5 sec( I2 t off).
Sometimes this MCCB is tripping .But no trip in DB MCB.
Can anybody tell me reason ?
From where i can know about the MCCB settings?

Answers were Sorted based on User's Feedback



WE are using a 63A MCCB(SIEMENS MAKE) for one of the feeder in LV substation panel.It is supplying ..

Answer / ranveer

Dear fren i think your Isd is very much high or it may
highest in. kindly che it out and may consult your vendor

Is This Answer Correct ?    4 Yes 1 No

WE are using a 63A MCCB(SIEMENS MAKE) for one of the feeder in LV substation panel.It is supplying ..

Answer / mukesh khatri

check the terminationa and lugs

Is This Answer Correct ?    3 Yes 2 No

WE are using a 63A MCCB(SIEMENS MAKE) for one of the feeder in LV substation panel.It is supplying ..

Answer / abdul

HI Friend,
I think there must be a earth leakage in your receiving end.
Always the MCB trips for Short circit,where as the MCCB
trips for both earth leakage & short circuit.

Is This Answer Correct ?    1 Yes 1 No

WE are using a 63A MCCB(SIEMENS MAKE) for one of the feeder in LV substation panel.It is supplying ..

Answer / kyle

Hi,

Is it instantaneous tripping? If it is, Isd might be too low
(in fact it is consider high in this case) and tsd might be
too short, need to check the downstream loads.

might to provide more info?

Is This Answer Correct ?    0 Yes 0 No

WE are using a 63A MCCB(SIEMENS MAKE) for one of the feeder in LV substation panel.It is supplying ..

Answer / naveen sahariya

This may be due to absense of discrimination feature in
DB.or cascading is not as per requirement.better to have a
word with siemens engineer

Is This Answer Correct ?    1 Yes 3 No

Post New Answer

More Electrical Engineering Interview Questions

why the name mho relay,despite the locus of circle is impedance?

1 Answers   KSEB,


Hello friends, Can anyone explain the concept of zones in Bus bar protection and how can we differentiate the main zone and check zone in Bus bar protection

1 Answers   ABB, NCC,


what is saturation kit?which use above 15 kw motors panel side.

0 Answers   Power Grid,


The efficiency of a 100kva transformer is 0.98 at full load as well as half load , for this transformer what is the Copper loss at full load ?

0 Answers  


if step down transformer step down the voltage,will current will also be proportional step up. If yes then how transformer handle such a large current?

4 Answers  






why we use Bus earth truck and Cable earth truck

5 Answers  


what's the different between ELCB, ELR and ELS?

1 Answers   CP,


Testing procedure of DG alternator stability test

0 Answers   Amprotec,


An ELHNC 80amp 240v 30mA RCD is tripping periodically, every 30 - 180 seconds is it safe to disconnect the protection circuit?

0 Answers   HAL,


Why do not we prefer non conventional sources of energy to conventional sources?

0 Answers   Nabard,


what is the difference between starter and control panel..?

4 Answers  


how the rotating magnetic fieldis produced in induction machines??? give the correct explanation.is there any mathematical expression for the same?

1 Answers  


Categories
  • Civil Engineering Interview Questions Civil Engineering (5085)
  • Mechanical Engineering Interview Questions Mechanical Engineering (4452)
  • Electrical Engineering Interview Questions Electrical Engineering (16637)
  • Electronics Communications Interview Questions Electronics Communications (3918)
  • Chemical Engineering Interview Questions Chemical Engineering (1095)
  • 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)