Answer / kj

Three phase supply is the least number of phases that will
produce a rotating magnetic filed. This allows 3 phase
induction motors to start without special methods as with
single phase.
Extra phases have been used at times but it increases the
costs of all the power lines.
Where 3 phase can be 3 or 4 wire, 5 phase would be 5 or 6
wire and 7 phase would be 7 or 8 wire.

Answer / kumar

for single percentage is less than the 3 phase % of power improvement 57% after increasing 5 ph, 7 ph %power is increased only 7% that's why we use 3 ph

According to underground cables a) stress b/w sheath & conductor is high b) inrush of core & conductor

0 Answers   CDS, Engineers India Limited, TNQ,

---

I have 320 Kva DG Set his KWh running is 77 , how i can calculate into electrical unit .

2 Answers   Anuj Enterprises, Schneider,

---

how to wiring 20 hp motor get completated?

1 Answers   Alchemist,

---

what is ground fault in ACB?

0 Answers  

---

i have 2 motor of same rating. on no load condition one motor take 1.6A but other motor is taking 4.8A. what is the reason of this. please explain with proof.

8 Answers   Ambuja, UltraTech,

---

why can't we increase the voltage by increasing the field voltage in order to get higher voltage.so that we can eliminate step up transformer

4 Answers   Bhel,

---

which type your UPS on line,off line give the reason?

2 Answers   Roto Power,

---

What are the two types of compensation?

0 Answers  

---

why PT Primary are the grounded?

5 Answers   L&T,

---

Hy the hydro power stations have high transmission and Distribution costs?

3 Answers  

---

What will happen if the armature resistance is in minimum position and the field resistance is in maximum position while starting the motor

0 Answers   Viva,

---

What is meant by "tampering detection" of a electrical energy meter?

3 Answers  

---