Answer / karthik

292

Answer / t s gupta

In balance star connection
Vr=Vy=Vb=Vph
Phase voltage (i.e. voltage across single phase) amplitude : 230 V
Line voltage (across 2 phases apart from 120 angle) voltage amplitude : square root 3*230 = 398 V not 440 V
This line voltage may referred as voltage of two phase shall be 398 V

Other hand both the Phase are 120 degree apart from each other and equal in magnitude hence the vector sum will be equal to the phase voltage i.e. 230 V

Why DC excitation is used for alternators? Why cant it be AC?

35 Answers   ABB, Ace Info, Alstom, Shalivahana Power,

---

how to calculate the capacitor rating for improving power factor

10 Answers   L&T, Property Solutions, Synergy, TAFE,

---

what is soft starter?working principle?where it can use?

3 Answers  

---

why we use Bus earth truck and Cable earth truck

5 Answers  

---

What is the advantage of Neutral graunding transformer insted of Neutral graunding Resistance in generating station explain briefly.

2 Answers  

---

---

Why substation battery room is coulered black?

1 Answers  

---

An 8 pole, 50 Hz, 3-phase IM is loaded to a poing where pull out torque will occur. The rotor resistance per phase is 0.3 ohm and motor stalls at 650 rpm. The rotor reactance at stand still is A 2 ohm B 1.25 ohm C 3.15 ohm D 2.25 ohm

0 Answers  

---

For what purpose and why ACBs are used

4 Answers  

---

Since phi is the angular displacement between V & I, then why we use phi in power triangle ie. when showing active, reactive & apperent power in triangular manner & if it is ok then where is V & I in the triangle.

1 Answers  

---

what is the maintaining Cf in UPS.

0 Answers   Enercon,

---

What is fault level? How can be calculate the fault level?

1 Answers  

---

what is the difference between the alternator used in hydro and thermal power plants??

2 Answers  

---