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
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 |
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 |
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 |
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 |
why the name mho relay,despite the locus of circle is impedance?
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
what is saturation kit?which use above 15 kw motors panel side.
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 ?
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?
why we use Bus earth truck and Cable earth truck
what's the different between ELCB, ELR and ELS?
Testing procedure of DG alternator stability test
An ELHNC 80amp 240v 30mA RCD is tripping periodically, every 30 - 180 seconds is it safe to disconnect the protection circuit?
Why do not we prefer non conventional sources of energy to conventional sources?
what is the difference between starter and control panel..?
how the rotating magnetic fieldis produced in induction machines??? give the correct explanation.is there any mathematical expression for the same?