Answer / sheikh

Do you means over & under current protection relay and under
, over voltage relay . if yes then symplestic matter where
is need of over and under vol,protection and where is under
and over current protection.

star delta starter contorl circuit... drawing..

0 Answers  

---

we use 3 phase supply for induction motor why not use two phase supply .

4 Answers   TLC,

---

how to calculate the transformer losses.

4 Answers   Cipla,

---

Sir we have 12.5 MVA(110/11KV) transformer (Y-Y) connected,which tripped showing earth fault,when we charged transformer it stood OK ,but on connecting 11 KV feeders it tripped showing earth fault.our service engineers found that the B phase and R phase phase connecting to neutral broken from HV OLTC(on load tap changer),and R phase and Neutral is ok.Dissolved gas analysis shows that accetline content is high,tan delta value is 12.My dout is it is an internal fault of transformer,why REF or diffrential relay is not acted?

1 Answers  

---

what is POTT and PUTT explain?

0 Answers  

---

In 2500kva transformer how much is the withstand High voltage power frequency between primary to secondary and earth? And secondary to primary and earth?

1 Answers   Honeywell,

---

Diode is active or passive element?

14 Answers   Infosys,

---

What is meant by shunt current?

1 Answers   ABC,

---

How does an oscillator differ from an amplifier?

0 Answers  

---

What is meant by Resonance what are the different types of resonance and what are uses of them?

14 Answers   Infosys, NTPC,

---

sometimes, eventhough the HV side of the transformer is opened there is a voltage in LV side .How is it possible?

4 Answers  

---

During a temperature rise test of a bus duct, it is fed with 415 volts at 2000 amperes. Why dont we get an electric shock if we touch the bus bars?

7 Answers   ABB, SDBL,

---