Answers were Sorted based on User's Feedback
Answer / anand
bwlow 1 ohm
|Is This Answer Correct ?||35 Yes||7 No|
Answer / anilram
for perfect earting it should be zero ohms. for pratically
at site it 1-5 ohms . in large substations the should be
below one ohm
|Is This Answer Correct ?||21 Yes||3 No|
Answer / seth roosevelt dabri
it is between o - 0.5 ohms in large substations the should be
below one ohm
|Is This Answer Correct ?||10 Yes||1 No|
Answer / sreenu
IT'S ABOUT THE RANGE LIKE 0.7 TO 0.8 . DUE TO COMPONENTS
PRESENT IN EARTH.
|Is This Answer Correct ?||16 Yes||10 No|
Answer / jan
No fixed rule. depends upon site. better keep it as low as
possible else high touch/step voltage
|Is This Answer Correct ?||6 Yes||2 No|
Answer / syed qamar abbas
The ideal value of earth resistance allowed is 1 ohm or less
for equipment's body earthing or grounding like generator,
Main distribution boards , motors etc. On other hand the
value of earth resistance allowed for lightning protection
system is 10 ohms (ideal)
|Is This Answer Correct ?||8 Yes||4 No|
Answer / bilal descon
1 ohm is ideal, but thats depend from place to place.
Near desert ares its more up to 20 ohm, but normally
betweem 0 to 25 ohm is acceptable
|Is This Answer Correct ?||10 Yes||7 No|
Answer / sethu
perfect earth value - 1.5 ohm
lighting arrest earth value - 1.7 ohm
|Is This Answer Correct ?||2 Yes||1 No|
Answer / anubhav gupta
Resistance of earth should be zero but it can't possible. however, according to NFPA &IEEE the resistance of earth is 5 our less
|Is This Answer Correct ?||1 Yes||0 No|
What is the difference between security constraint unit commitment and security constraint optimal power flow?
how many earthing is required for sever room?
Why 11KV PT Secondaries [(11000/1.732)/(110/1.732)/ (110 / 3)]are in star connection ? And why the same should not be in delta ?
what is the signification of trivector meter? why its name is trivector meter ?
what is the difference between H.T Or HV lines...?
how you connect the induction motor first in star and then delta in star-delta starter
what are the values to be accepted on 3 core 185sq mm for 11000volts on insulation resistance between conductors and between conductors and earthed?
without name plate detail of blower how we can find out the HP & Rpm ? the input voltage is 230v single phase
there is a power transformer 66/11kV in delta-delta connection has 5 feeder coming out from the secondary side. One of the feeder in it normally loaded (loaded than other feeder)and this feeder usually trips with double OCR causing the bank transformer to trip. Now if the load of this feeder is put on other transformer then that no problems occurs on that transformer or the load. However normally all the test(IR, PI, short ckt, open ckt,grounding test and other ) has been conducted for this but evertything transformer..... I am not geting what is the actual problem...
Grounding. Dear all at one of my site we checked the amps at the earthing cable to the alternator it was found 125 to 130 A. at the neutal cable in same machine found 146A. in the same plant checked the earthing current on other alternator it was 52A, and neutral 116 A. we are facing problems with our controller and the card was damaged once. can that neutral/GND current be a reason? as there is common grounding for the Alternator,Brkr panel,Transformer?
what is "PE" earthing? and what do u know abt 16mm cable?
how much Amp we can put in 1200kva generator?