ALLInterview.com :: Home Page            
 Advertise your Business Here     
Browse  |   Placement Papers  |   Company  |   Code Snippets  |   Certifications  |   Visa Questions
Post Question  |   Post Answer  |   My Panel  |   Search  |   Articles  |   Topics  |   ERRORS new
   Refer this Site  Refer This Site to Your Friends  Site Map  Bookmark this Site  Set it as your HomePage  Contact Us     Login  |  Sign Up                      
Google
   
 
Categories >> Engineering >> Electrical Engineering
 
 


 

 
 Civil Engineering interview questions  Civil Engineering Interview Questions (3114)
 Mechanical Engineering interview questions  Mechanical Engineering Interview Questions (3298)
 Electrical Engineering interview questions  Electrical Engineering Interview Questions (13420)
 Electronics Communications interview questions  Electronics Communications Interview Questions (2382)
 Chemical Engineering interview questions  Chemical Engineering Interview Questions (420)
 Aeronautical Engineering interview questions  Aeronautical Engineering Interview Questions (77)
 Bio Engineering interview questions  Bio Engineering Interview Questions (17)
 Metallurgy interview questions  Metallurgy Interview Questions (80)
 Industrial Engineering interview questions  Industrial Engineering Interview Questions (165)
 Instrumentation interview questions  Instrumentation Interview Questions (2393)
 Automobile Engineering interview questions  Automobile Engineering Interview Questions (107)
 Mechatronics Engineering interview questions  Mechatronics Engineering Interview Questions (38)
 Marine Engineering interview questions  Marine Engineering Interview Questions (45)
 Power Plant Engineering interview questions  Power Plant Engineering Interview Questions (78)
 Engineering AllOther interview questions  Engineering AllOther Interview Questions (1202)
Question
how to do CT Burden test
 Question Submitted By :: Electrical-Engineering
I also faced this Question!!     Answer Posted By  
 
Answer
# 1
When a CT is used in a metering circuit it will have a
secondary current loop connecting its output through a test
block to a meter . This current loop will consist of a
secondary wire from its X1 terminal to a test block and go
through a shorting switch. From the shorting switch the
current loop will have a wire connection over to the meter,
go through the meter, and have a wire connection back to
the test block. From there the current loop will go through
the secondary current test switch and have a wire
connection return to the X2 terminal of the CT with a
connection to neutral either at the output of the current
test switch or at the X2 terminal of the CT . This
secondary current loop has an electrical impedance called
its burden. This burden will have a resistance component
and may have an inductance component. Usually the
inductance component is small and is treated as negligible.
The burden of the secondary circuit, as installed, is
designated the natural burden of the circuit. If installed
properly the natural burden should be less than a few
milliohms. The CT is designed to operate accurately under
certain burden conditions as specified. The accuracy class
certification of a CT is presented for a stated upper value
of burden, called the CTís rated burden. For example it may
have an accuracy class of 0.3 for burden of 1, meaning that
the CTís rated burden is 1 ohm and the CT will maintain
accurate rated ratio performance within 0.3 percent for
secondary circuit burdens up to 1 ohm. This rated burden
classification is also stamped on the CT nameplate. If the
natural burden of the secondary circuit is larger than the
rated burden, then the CT is not certified to have accurate
performance. For this condition, called over-burdened, the
secondary current will not be accurate tending to be
somewhat less to significantly less than the accurate value
causing the metering to be in error in favor of the
customer. Furthermore, secondary circuits may have burden
build up as they age due to loose connections, corrosion,
broken stranded wires, etc. CTís, as installed, need to
have enough excess burden capacity over the natural burden
to allow accurate performance over time even if there is
additional burden build up in the secondary circuit.
 
Is This Answer Correct ?    2 Yes 2 No
Kay Pee Corporation
 
Answer
# 2
thats CT saturate voltage thats we can see in the table to
decide the CT size and accuracy the formula for calculate

total resiatance * Fault current
Voltage at the time of fault-------------------------
CT ratio
For example that voltage 34Volts and the ct saturate
voltage 40Volts thats a knee point so we select a ct that
have less than 40volts
 
Is This Answer Correct ?    0 Yes 0 No
Saad
 
 
 

 
 
 
Other Electrical Engineering Interview Questions
 
  Question Asked @ Answers
 
What is Engine? HSL 6
TO operate transformers in parallel, vector symbol of the both should be same.If one transformer name plate is not there, how can we conclude that whether the transformer is having the same vector symbol or not?   4
A 100 MVA transformer may be cooled with? HCL 6
In power transformer YnD0 Vector Group is possible or not? if possible, what will be the vector diagram and what are the conditions?   2
what is potentiometer & rheostat   3
I have 1500KVA transformer ,How much Maximum KW Load is allowed?   10
when we start the tube light, then it takes initially 1100 volt, after glow it takes 120 volt?(when we give 220 volt a.c.)   2
what is load balancing. what maximum load diffence is allowed between phases.   1
What happens to the terminal voltage of an alternator connected to a bus bar when it is suddenly disconnected from the bus bar??   2
How can we step up ac and dc ?   1
What is the method to calculate the capacitor bank rating for say 50 KW load and how do we connect each capacitor to busbar??   4
purpose of breaker contact multiplication relay? ABB 4
 
For more Electrical Engineering Interview Questions Click Here 
 
 
 
 
 


   
Copyright Policy  |  Terms of Service  |  Articles  |  Site Map  |  RSS Site Map  |  Contact Us
   
Copyright © 2013  ALLInterview.com.  All Rights Reserved.

ALLInterview.com   ::  KalAajKal.com