Answer / raj

IT IS NEUTRAL DISPLACEMENT RELAY AND IT IS USED FOR VARIOUS
PROTECTION BUT THE PRINCIPLE IS THAT IN CASE OF NO FAULT NO
VOLTAGE IN RELAY ( IT USED OPEN DELTA VOLTAGE FOR RELAY
INPUT ) AND IF FAULT OCCUR IN ANY PHASE THEN UNBALANCED
VOLTAGE WILL GET ACROSS OPEN DELTA FOR RELAY TO OPERATE.

Answer / k.prakashchandra

It could be non-directional relay which is cheaper than
directional relay and used wherever current is not expected
in both directions.

what happens to the supply voltage if there is any change in frequency?

1 Answers   Gridco,

---

How many points can we have in AC Circuit? Show by giving suitable example?

3 Answers  

---

how many test is necessary for 27mva transformer.

3 Answers   HEG,

---

what is meant by AYFY Cable?

9 Answers   XLPE,

---

keeping in view of parallel operation which of the 3 phase transformer connection are possible? a)delta-delta to delta-star b) delta-delta to star-delta c) star-star to delta-delta d) delta-star to star-delta

4 Answers   Ecil, Siemens,

---

I have 1 KW, 3ph. 440v, 50 hz, cos(phi) .75, efficiency 75%(star delta connection)Motor. How to calculate line current & Phase current (1) Star connection (2) delta Connection

2 Answers  

---

WHY CURRENT DECREASES WHEN VOLTAGE IS INCREASED IN A CURRENT TRANSFORMER ?

5 Answers   Sterling Wilson,

---

what is earthing/

3 Answers   B.Tech, CPCL, Mobiserv,

---

What is delta stare switch?

1 Answers   Samsung,

---

What is the pro & con of having 11kv & 33kv incoming, and what is the adv & disadv. of converting from 11kv to 33kv.

0 Answers  

---

What is the necessary condition for stability.

0 Answers  

---

how does an energy meter works?

4 Answers  

---