Answer Posted / venkatesh a
NGR- Neutral ground resistor.
Used to limit the ground fault current.
If the Line voltage getting leakage or shorted with ground
then fault curretn will flow.
If it is High voltage system this fault current will be
very high (KAmps). So this much high value fault current
will demage the fault current sensing devices (relays).
This fault current will reach the transformer Neutral
through the Neutral earth pits.
By adding the NGR in between the Transformer neutral and
Neutral earth pit, resistance of the fault current path
getting increase.
we Know that, resistance is more then the (fault) current
flow will be less.
Then easy to sence. Normally resistance will be 12 to 15
ohms depends upon the setting made at relays.
| Is This Answer Correct ? | 29 Yes | 3 No |
Post New Answer View All Answers
What are the advantages and disadvantages of negative feed back?
what is relay what is protection & contact multiplying relays where it is used function in brief
What is the suitable transmission voltage?
what are carbondioxide and dcp used in fire extinguishers
How to back charge the Gas turbine generator
33kv substation lay out details & line to line & line to earth measurements
When we use 3 terminal resistor?
234 MVA Generator 3 phase Short circuit current Values required? Gen set Rating-234 MVA, Gen Voltage-18kv, PF;0.8, Xdv:23.5 %, Transformer Rating-18/380KV, 680MVA,Yndd1 two winding, Step up TR, ZT:35.50 %,X/R 4.33 Gen CB Position, CB open ,Disconnected open, Generator Running Voltage 18 Kv, Bi mistakes generator side earth switch Closed during that time short circuit current level in 3 Phase required, and how to test on site 234MVA Generator Short circuit current,
tell me some type of questions throught which i can prepare for exam and do my best
what purpose to use excaiter in DG.?
hi,every one, i have to write the search paper on "performance policy optimization" of NGN (next generation networks). i need the material on this topic. can any body help me. please tell me any useful site where the good material is available and name of any reference book. it should be a great help for me.
what is the cause of voltage dipp or swell in the transmission lines?
draw singleline diagram of star to delta and dol starters
I am designing new project sub station with 220 kV / 11 kV, 40 MVA capacity. This project have many recifier sets, which can generate 3rd harmonics. Now I have to select vector group of This transformer. To minimise 3rd harmonics, what care should I take in selection of Transformer Vecrtor group? If it is Y-Y with open Delta tertiary then what should be the rating & voltage of Tertiary Winding?
What is slip in an induction motor?
