in our 6.6kv motor feeder[it is having two sources from
Bus A&B] earth fault relay is acting, we checked CBCT
connection and cable meggerd values found very good still
earth fault acting during first two are three start after
that it will hold. please clarify what was the reason. if
same motor is starting from other Bus-A it will start.
Answer Posted / a.p.nanjappa
WHAT IS THE TYPE OF 6.6KV SW.GR. hOW OLD IS THIS?
tHE EARTH FAULT RELAYS ARE VERY SENSITIVE. INSULATION
RESISTANCE OR MEGGER CAN NOT MEASURE.
CARRY OUT HV CAPACITANCE MEASUREMENT OF MOTOR,CABLE FEEDER.
AND hIGH POT TEST.
MEASURE THE TANGENT DELTA FROM DC HIGH POT.
IF MIN OIL CIRCUIT BREAKER,TEST THE OIL AND REPLACE.
WE ALSO EXPERIENCED THIS DUE TO BURNED CEREMIC/BAKELITE
PARTITION PLATES OF 6.6KV SW.GR
| Is This Answer Correct ? | 0 Yes | 1 No |
Post New Answer View All Answers
Draw transformer phasor diagram.(full load,no load)
why tertiary winding is used in transformer with diagram?
What is the ratio of Booster transformer?
what is the diference between the 4pole & 6pole DC Motors & what is advantage 6pole over the 4pole ?
what happen as when voltage drop(or may decrease) ? in case of atomic base theory?
What is essential to prove safe isolation of electrical circuit?
IN SINGLE PH TRANSFORMER IF LEKAGE IMPEDANCE DROP IS NEGLECTED ,THE FLUX IN THE MAGNETIC CORE and the lekage flux linking a winding are a)proportional to the applied v to the winding i respectively.
Will any motor burn if voltage provided is lesser than the rated voltage???? If yes, then how is speed control possible with voltage control
difine electrical ballast in HPSVL
what is the formula for efficiency of francis turbine and generator for hydropower? what is best way to select francis turbine and generator?
i want use the cable size 16cx4 core aluminium usege watts 240x2000w this cable size is correct?
what will happen if frequency is below 50 hz?
i have attended the interview on 4th June,08 at Kolkata in IOCL, can anybody tell me what is its result
how rectifier transformer work in electroststic precipetatore(esp?
In a single how much maximum current and watts using