Answer / jay kolhar

Neutral point or the mid-point connection is earthed in such
a manner that , even under fault conditions, the maximum
voltage that can occur between any conductor and the earth
does not exceed 80 percent of the nominal system voltage .

Answer / shuja

urs anw are right accourding to u,,,,,,,,,,,,,,,how can we
understand..so give simple answere

Answer / gautam patel

For earthed and un earthed XLPE cables, the IS 7098 part2 1985 does not give any difference in specification. The insulation level for cable for unearthed system has to be more. In simple statement the manufacturers states that 11 KV earthed cable is suitable for use in 6.6 KV unearthed system.The process of manufacture of cable is same. The size of cable will depend on current rating and voltage level.

Answer / vishnu k vyas

in Ungrounded system if L-G fault Occurs then voltage
acroos healthy Phase Becomes equal to Line Volatge
(1.732xVph).so per phase insulation requirment will be more
in un grounded Cables.

Answer / raju karmakar

The insulation level of earthed cable is less than uneath cable. If the system voltage is 33KV than the mark on cable will be 33/33KV on uneath cable and 33/19KV will be on earthed cable. It means than during fault in R-Phase the voltage of other two phases will rise to 1.732 times of system voltage. If the rated voltage is 19KV than the insulation of earthed cable will damage. But the unearth cable will stand.

Answer / bhavin machhi

Eath and unearthed cables are related to their continuous load on cable and for that load in unearthed cable xlpe insulation is more. For examlple if cable is used for power transmission then it will have all time full load while if it is used to supply any equipment then it will have different load and variation in load as per load on equipment.

Answer / iyyappan

m.iyyappan
if the system unearthed then the thickness insulation of the cable 4.5
if the system earthed then the thickness insulation of the cable 3.4
phase to ground fault means other 2 phase voltage rise of squ..root 3.

Answer / thrimurthy

Unearthed cable inner insulation level is high and this cable is using in high voltage side. earthed cable insulation level is low and this cable using in low voltage side.

Answer / s.dineshkumar

as per the discussion all are mentioned compatibly
unearthed cable have more insulation. That’s concept is
correct but which insulation outer side or inner side? The
answer was inner side insulation. Inner side insulation
only differ the property of the cable XLPE or PVC, etc…

Answer / joker

Thoes cables are under earth called earthed and thoes cable above earth called unearthed. am i right??? Its joking...

how to check the continuity of a cable with a megger

4 Answers   Metro,

What is mean CT Saturation? How to calculate?

3 Answers   NetGroup, Tyco,

In alternator generally we give DC voltage to field of alternator but field (excitor)produce Ac & converts into DC by rotating rectifier(RR ) then fed to rotor .my question is why we cannot give dc voltage directly to rotor instead of Excitor & RR ?

1 Answers  

Dear Sirs, I am a technical persons.In one of our Electrical Sub- Station, We have installed three numbers of 1250KVA ,11KV/0.415KV Transformer to feed the Factory load. We have found some abnormality. In one of our Transformers the leakeage current from transformer body to earth through earth continuity wire is almost 86 Amp but in other transformer it is (5-10)Amp. where the load current on three phase and neutral are respectively 1360Amp,1400Amp,1370 Amp & 176Amp. So please any technical person help me about the reasons of this situation and how I can rectify the fault. Moreover,I have measured the earth resistance of the Earth continuity wire which is less than 1 Ohm. Thanks Tapas Barua

3 Answers  

what is the work of trip circuit supervision relay?

2 Answers   Volkswagen,

Rotor is taken away from three phase induction motor and three phase supply is given to the stator.What will happen?

9 Answers  

Upto what extent, the lagging power factor can be improved with the help of capacitors?

6 Answers  

i have one transformer 1000kva, 11/.433kv. we are using 200/5 amp. ct unit for measuring purpose, & one 800 amp. V.C.B Unit for the same t/f operate, i wants to known the primary current of T/F is only 53 amp. why we used 800 amp. V.C.B ? & 200/5 amp. CT Unit.

4 Answers  

Why wind turbines wheels rotate constantly

0 Answers  

What is the difference between ELCB and RCD

7 Answers  

HAI,HOW TO SET THERMAL OVERLOAD RELAY FOR DOL STATRTER FEEDER AT START AND RUNNING?

4 Answers   L&T,

When distance between two pulleys is not fixed, the tension of belt is adjusted by a) driver shaft b) driven shaft c) adjustment screw d) belt

0 Answers   BMRCL,