how to calculate the ngr capacity(nutral grounding resistor)
Answers were Sorted based on User's Feedback
Answer / vinod
NGR capacity should allow the mininmum earth fault current
so that system with minimum earth fault current can be
detected and isolated by earthfault relay.
ie NGR fuction is to reduce the earth fault to the minimum
level in the range of earth fault relay
Is This Answer Correct ? | 7 Yes | 0 No |
Answer / raghavendran.r
As far I know the formula is Rngr = Vln/Ig.
where Ig is the current flowing through the Neutral Grounding resistor(let through fault current), which depends upon the type of system you haver chosen, i.e High impedance grounding or Low resistance earthing.
The let through ground fault current through the neutral is low for High resistance earthing and its High for low resistance earthing.
But the important condition is that the let through fault current should be greater than the system capacitive charging current to avoid transient over voltage.
Is This Answer Correct ? | 2 Yes | 1 No |
why voltage is low at reciving end in summer??
is there any difference in reading or error in value, if we connect the R phase in Y terminal and Y phase in R terminal of electronic energy meter of 11 kv feerders???
SUTIABLE FOR ohm's law super conductor
whether a separate starter is used for a motor while it is connected to a vvvf panel?
For a DY11 lighting Transformer on primary side whee to connect fourth lead? from nuetral or from ground?
What is the difference between class0.1 and class 0.1s accuracy of current transformers
how much amps will get from a 360/11kv line
what is power transformer?
Where is 2 phase supply used commercially?
why transformer neutral and CT Secondary neutral is connected to earth?
1. Why transfomer reting in KVA and Motor in HP
11 Answers AirIndia, Jindal, Mind Tree,
how the transformer stables out zone faults? Because we use non directional O/C relays .Is there any special considerations are taking into account to overtake this?