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 |
we change the speed of the synchronous motor by incresing or decreasing a rotor resistance
why we used servo motor insted of inducation motor?
WHAT IS THE MEANING OF CYWY
What is the use of IGBT in UPS & its working??????????
What is a parabolic signal?
75 kw motor take 45 amp in no load delta in star 10 amp but in load it will take 160 amp but IR velue of winding above 500 at 1kw ph to earth and ph to ph. what problem it should be?
Can any body tell me about Hi-pot test, and why it is necessary and its procedure of testing
what will be efficient rating of ac motor to lift a 10 kg wt of stone to 10 meter height with input 220V AC 50 Hz frequency???
what r substations?what r there work?why voltages r incresed and then reduced during distribution of power
What is the role of ESP(Electro Static Precipitator)in steam power plants? Where it is located? How it works?
The CHARGED BATTERY GET DISCHARGED WHEN IT IS NOT IN USE FOR LONG TIME.GIVE REASON.
WHAT IS MEANT BY BTU OF AIR CONDITIONERS.