Answer / sibananda jena

For starting the engine, and for excitation voltage for the
alternator.

Answer / abhishek

main alternator excitation voltage supplied after rectifying
another small alternator voltage. This small alternator excitor
voltage is supplied by battery.

why the secondary current transformer cannot left open

1 Answers  

---

how can service sitting be setted for MCCB?Example for sittings IR (CURRENT RATING),IS(CURRENT STARTING)IO (current operating)?

0 Answers   SISL,

---

how to caluclate cable size by Amps

2 Answers  

---

There is one 40MVA oil cooled transformer (yet to commission), filled with 95% oil and we are trying to fill 5% Nytrogen in that transformer so that there should not be any foreign component inside. But even though there is no leakage, nytrogen is not withstanding inside transformer, within a day or two pressure guage is showing 0. Why is it soooo? Pls reply.

1 Answers  

---

In Air circuit breaker LSIG protection unit is used. Without fault in cables (2 runs 3Cx150Sq.mm Copper, 1Kv grade, XPLE armored cable IR value is more than 550Mohm @ 500V Megger) and load section Long time Overcurrent protection is triggers and trips the unit. We changed LSIG protection with new factory tested unit. Even then fault is persisting. Please suggest the possible causes

0 Answers  

---

A powerplant has 8 gensets operating in grid parallel mode. In one genset sometimes there is pf variation and kvar variation. The plant operates in pf mode. When this variation is observed the load is stable, voltage is also stable, freq and genset speed is also stable. How will you check the functioning of pf card. What shall be the ideal output vdc of the pfc, from there it is input to AVR?

0 Answers  

---

the max. power will be transferred if …… a) sending end vol. is high b) receiving end v is high c)…….. d) corona loss is least

2 Answers   Engineers India Limited,

---

Why is shaft current insulation required on large motors & when should it be checked i.e. before or after assembly?

2 Answers   Aramco,

---

How much current can 11KV line carry? What are the formulae used to calculate current across both side of transformer? Moreover I need to know can I connect 33KV line with transformer of 1600KVA? Details are: V=415, Pf= .9

3 Answers  

---

What is meant by soft starter used in motors?

4 Answers  

---

what is the carona effects meaning in HT line transmmission system

0 Answers  

---

What is difference between A.C & D.C Resistance ?

4 Answers  

---