Question { Reliance, 15892 }

Do you know the alignment of a motor?

Answer

yes,
if we hold a shaft of motor and try to rotate it if it will
easily rotate without any sound, problem then it is ok and
and if it not then it needs a little adjustment on both of
its side

Question { NCC, 109224 }

What is mean CT Saturation? How to calculate?

Answer

Sorry to say Mr Kiran Patil if CT is shorted ckted then it
will complete the ckt and save it from any further damage
and meter connected to that CT not able to read current
flowing from that CT.

There are two simple way to calculate the CT saturation
1. There is an instrument operates on 240v,50HZ known as RED
PHASE instrument it is an Australian instrument.
2. Primary injection method in this method we use an
instrument which can only provide current to both of the
primary position of the CT known as P1,P2 and secondary of
that CT are being short ckted so as to calculate the current
and with the help of tong tester we can calculate the
secondary current.

for example we are having CT ratio of 10/5 A and we are
providing primary current of 10 A and from secondary point
we are calculating 5 A current then CT are OK but if we are
getting lesser current than we must say that CT are saturated.

Question { Siemens, 7409 }

what is CT class? depending upon which it is classified?

Answer

CT class is the class of accuracy of instrument standardised
by indian standard (ISO).
For example if a CT out put is of 5 ampere if it gives out
put between 4.5 to 5.5 ampere than it is with in limit but
if it increase than it is out of limit and needs to be
replaced making electrical department loss of lakh per year.

Question { DLF, 18243 }

Why use the VCB at High Transmission System ? Why can't use
ACB? Pls explain the ans.

Answer

i'm sorry to say that above two answer give above are half
correct. because all u r talking about ionized air if u ever
open Chamber where CT's and PT's are connected u will find
distance less than a hand away and there is no problem of
ionized air there.
The main reason after that is at a time of breaking a ckt or
can say shutting down a ckt when load is not completely zero
there can be big damage or accident because of higher
voltage rather if load is completely zero then there is no
problem.
and ACB are used in low tension line where low voltage and
higher load can be controlled.

Question { Dalkia, 70723 }

how to calculate the multiplication factor in HT incomer
trivector meters

Answer

To calculate MF(multiplication factor) we must know current
transformer ratio and meter ct ratio

mf = current transformer ratio/meter ct ratio

Question { 8075 }

difference between ac and dc generators

Answer

DC generator is a machine which gives DC current as out put
and AC generator is a machine which gives AC current as out put.

To convert DC generator to provide AC current commutator
rings are provided on its end.

In DC generator DC machine is used as an generator where as
in AC generator synchronous machine is used as an alternator.