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 (3156)
 Mechanical Engineering interview questions  Mechanical Engineering Interview Questions (3310)
 Electrical Engineering interview questions  Electrical Engineering Interview Questions (13485)
 Electronics Communications interview questions  Electronics Communications Interview Questions (2396)
 Chemical Engineering interview questions  Chemical Engineering Interview Questions (424)
 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 (166)
 Instrumentation interview questions  Instrumentation Interview Questions (2409)
 Automobile Engineering interview questions  Automobile Engineering Interview Questions (109)
 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 (81)
 Engineering AllOther interview questions  Engineering AllOther Interview Questions (1207)
Question
WHAT IS THE FUNCTION OF EARTHFAULT RELAY?
 Question Submitted By :: Electrical-Engineering
I also faced this Question!!     Answer Posted By  
 
Answer
# 1
Earth fault relay is a relay which is sense the faults
between the phase and Earth (not b/w neutral to earth)
 
Is This Answer Correct ?    69 Yes 14 No
Ravi Kumar
 
Answer
# 2
Actually earth fault relay's function is,it calculates the
vector sum of all the three currents flowing in R Y B
lines. If the vector sum is not zero then there is a fault
current flowing in particular line. since these lines are
connected to load say generator then, more than the rated
value of current flowing through windings ,hence windings
will damage so to prevent these type of damages EFR is
used.
if any comments pls send to shreeshara@gmail.com
 
Is This Answer Correct ?    62 Yes 8 No
Micro Power System, Bangalore.
 
 
 
Answer
# 3
The function of earth fault relay is to to protect the
device from earth fault. there are 2 types of earth fault
fault relays

1.neutral ct conneted earth fault relay. it will sense the
current flowing through neutral while earth lerakage.

2.three phase ct's connected earth fault relay.in normal
condition the sum of three phase ct's current in zero.

when earth fault the sum of the 3 phase ct's curret are un
balanced that time relay acts.
 
Is This Answer Correct ?    20 Yes 0 No
Sennapparajan
 
Answer
# 4
Function of the earth fault relay is to operate for the
leakage currents to earth. There are two types of earth
fault relays depending up on the configuration
1. Residual current earth fault relay
2. Sensitive earth fault relay
 
Is This Answer Correct ?    21 Yes 2 No
T Eswara Rao
 
Answer
# 5
I agree with Mr.Ravikumar except in one point.
If the load distribution of a 3 phase 4 wire system is not
balanced in all three phases, there will be some potential
in neutral wire and thus a current flow also.
In this condition, if the neutral wire touches to earth
after the earth fault relay CT, definitely this E/F relay
will sense this current flow from neutral to earth and thus
trip the circuit.
If any other disagreement, please mail me at
pratheeshtn@gmail.com.

Thank you.
 
Is This Answer Correct ?    20 Yes 3 No
Pratheesh
 
Answer
# 6
earth fault relay is a device used protection.
when an unbalance current flows through the line this relay
operates and trips the circuit breaker.
earth fault relay is used between phase and earth faults..
 
Is This Answer Correct ?    11 Yes 2 No
Madhu Kiran.g
 
Answer
# 7
1.the earth fault relay funtion is to senses and derived
the current from phase to earth fault


depands upon the ct connections used in the scheme
the earth fault relays are classified
1.residual earth fault
2.stand by earth fault
3.restricted earth fault
4.senstive earth fault
all will be derived the input currents from different ct
connections
 
Is This Answer Correct ?    8 Yes 1 No
C.venkatesan
 
Answer
# 8
Earth fault relay is sensing the fault between phase to earth and also neutral to earth. When current flowing through earth that time it will be tripped. 
Is This Answer Correct ?    6 Yes 1 No
Sethurama.
 
Answer
# 9
earth fault relay operated between two phases for unbalcing
voltages
 
Is This Answer Correct ?    7 Yes 3 No
Visaw
 
Answer
# 10
The E/F relay will operate under unbalanced condition
i.e 1) during earth fault
2)During any phase open (when unbalanced current
exceeds the relay settings)

regards
gova
 
Is This Answer Correct ?    5 Yes 2 No
Gova
 

 
 
 
Other Electrical Engineering Interview Questions
 
  Question Asked @ Answers
 
why are we adopting 132kv,220kv for transmission rather than using 440kv at all transmission lines as it gives lower losses? APGenco 2
BRIEF ME CHECKING PRCEDURE OF BATTERY 12V 26AH DRJ-ARDE 1
why transformer rating in kva and motor rating in kw   10
Difference Between B Curve & C Curve in MCB.   2
Energy metering: On the property I am renting, the supply voltage is 2 x 110 volts. These 2 x phases enter a energy meter which then exit the meter to over head lines to my house. Question 1. The meter is single phase 240 volts but is being used as 2 x phase(2 x 110volt), is this acceptable? if not, please give me the reasons. The meter details are as follows: 60Hz 15amp Imax 100 amp Kd 3,6 Wh/R 1 fase 3 hilos Model FX 231. I think it was manufactured in Brasil From this meter, the cables run along over head aluminum conductors,I estimate the cross sectional area to be 25mm diameter, but the neutral is only about 10mm square diameter, which cover a distance of 170 meters and then terminate with an underground cable of 65 meter length, total length = 235 meters. There must be a huge voltage drop over this length. This line is protected with 2 x 200 amp aluminum fuses after the meter, there is no main switch in the distribution board. These 2 phases connect directly onto 2 busbars. Surely the neutral should be the same size as the conductors if not more? Question2. What are your thoughts about this installation, should there be better protection, is the neutral too small? During the night, the lights dim then brighten all the time, this cannot be good for my electrical appliances. In my home, I only have a small electric geyser and fridge, my stove works off gas. But when i use other appliances like the washing machine or microwave oven, the light dim. The internal wiring of this house is done with solid hard drawn copper wires and of course, they have to be under rated. I am a retired electrician by trade, but not on the metering and over head mains side, my experience is on the factory maintenance side of things. Your expertise on these matters will be greatly appreciated. Please inform me how to rectify or make any improvements Kind regards, my power bill is very expensive, so I need to know how to bring it lower. Kind regards, Brian   1
What is the difference b/w RMU & substation   1
AVR is used for the Voltage regulation of the Generator using the feedback signal by exciting the field winding of the generator.But how the field winding will be excited & using what? Alstom 2
What is the operational principle of direct current current transformer and direct current potential transformer?if possible plz reply with ckt. diagram.   1
in india ac frequency is 50hz, but in foreign countries it is 60hz,whwt is the reason   8
what happens to the speed of a DC series motor when series field winding is removed?   8
Why Humming noise originated in Starter motor and how it was generated ?   2
what diferent amoung three phase supply?   1
 
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