Answer / ranjan sannyasi

Many of test over an 3 phase transformer you can done, you
have to mentioned about megger test,so that test what actual
done,it's ur qsn...may i r8?
so, It's actually IR test means Insulation Resistance(IR)
test,how much insulated the transformer winding in between
their winding(primary & secondary).You could be known by
meggar test.
1.1st You have to do the PHASE TO EARTH test,how to do the
test? megger have two terminal,one of them you have to
connect with 1st phase (R-phase) or whatever(it may be
another two Y or B),must be one by one,it ds'nt matter ok,&
another with transformer body,its the earthing path.
regarding this test obtaining three of value must be
100,it's must be noted that 100 value is the accurate,if any
of value is 0 then some where in b/w winding & body it may
be leakage,for that DC current** is flowing through the
winding to earth.

2. 2nd test is the vital one.It's PHASE to PHASE TEST.It's
done by like that, suppose megger one terminal is connect R
phase and another one done by Y phase, so like that 1st R-Y,
2nd Y-B & last B-R, same you have find 3 value,like above
those.If all the value are 100 then its insulation b/w
winding are accurate,there have no insulation fault.

Answer / k.prakashchandra

With all the connections removed 1.Primary to body 2. Sec to
body 3.Between Pr and Sec .Find PI value also

What is the use of arc chute in ACB?

7 Answers   lenovo,

---

what is the difference between static and dynamic induced emf?

14 Answers   College School Exams Tests, MRF, Suraj Constructions,

---

what are the basic insulation levels & what its Unit

0 Answers  

---

What are the various types of BUSBAR Schemes? explain each

1 Answers   NTPC,

---

I want to know that a 160kva diesel generator contains capacity of 160kva on each phase like R=160 Y=160 B=160 total RYB=480kva or it is total capacity of all there phases like RYB=160kva ... thanks in advance ...

2 Answers   jlpl, JP Saraswat Engineers,

---

7- What is the Dissipation Factor and the difference between it and Insulation Resistance Test? 8- What is the task (function) of DC and AC reactors in power plant? 9- What is the task (function) of (open delta with earthed) in some types in transformers? 10- What is the base of the selection of the vector group in transformers? 11- What is the zig-zag transformer and its function by drawing in large detail? 12- What is the polarity ? 13- Why we make short between phase(R) in high side and phase (r) in low side in vector group test? Where High Side ( R ,S and T ) and Low Side ( r ,s and t ). 14- What are the time on delay and time off delay? 15- What is the vector group? 15- What is the task (function) of different types of vector group such as Dyn11 , Dd0 , YNd1,……..,?

0 Answers  

---

how to calulate multiplying factor if meter ratio is /5 ampere and ct ratio is 100/5 ampere.(our supply is 3 phase 415 volts)what is multiply factor?

3 Answers   Vivek Engineers,

---

if we convert watt into kva,which one formula use by us,pls tell me?

16 Answers   ABB,

---

what are the different type of transformers available in markets???

6 Answers   Atomic Energy Commission,

---

How to select cable rating for HT/LT Panels

1 Answers   Alstom,

---

What can make the the overloads operate when a star delta three phase motor starts?

1 Answers  

---

Please let me if star point(Nutral) of Delta/ Strar transformer, in 4wire (TPN+E) is tobe gruonded seperatly,inaddition to LV Panel earthing????

1 Answers  

---