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  

---

For Electrical / and Electronic Systems, when we say efficiency is 80%, then what happens to other 20% from the Power consumption.? I.e. what happens to this?

1 Answers  

---

Which one is more accurate servo or stepper motor and why?

2 Answers   BARC, HPT,

---

A circuit breaker is a

9 Answers  

---

What is cable tray, its type, and its support?

0 Answers  

---

how to interlock 3 nos MCCBs using under voltage coil. please provide me circuit diagram?

0 Answers   Honeywell,

---

what convarts RRA in alternator ,AC to DC or DC to AC,

1 Answers   Birla,

---

How much is the starting current for HPMV lamps. How many lamps can u wire in a circuit

1 Answers   Technip,

---

Difference between ELCB and RCCB?

5 Answers  

---

state application of relay in transmission line?

4 Answers  

---

If ROC does not lies inside unit circle,then ? a) Fourier transform converges b) Z transform converges c) Hatly transform converges d) Colpit Transform converges.

0 Answers   CCP,

---

how the testing of protection CT Testing done through Primary injection kit please describe in detail procedure...

0 Answers  

---