Answer / abdul rahman

Required capacitor KVAR :- KW X [tan cos (inverse(power factor old = 0.8)))-tan cos (inverse (power factor new = 0.9]

KVAR :- 15(TAN(C0S INVERSE (0.8)-TAN(COS(INVERSE (0.9))
= 15(TAN 36.86-TAN 25.84)
= 15(.75-.48)
= 15(.265)
= 4 KVAR 

Answer / k.prakashchandra

Using formula KVA^2= KW^2 + KVAr^2 ,find the values KVAr at 0.8 and 0.9 pfs. The difference is the required KVAr of the capacitor

What is rated value? is it phase values or line values?

1 Answers  

---

why some time Railway Fan not Rotate,But after a small rotation by human then it rotate normally? Why?

4 Answers  

---

What are the limitations of Kirchoff's laws?

0 Answers  

---

hi every body i am master student in control engineering and my project is slip control in trains i assumed a Dc motore as traction motor but i don't have characteristics of this kind of motor that is used in train. i want from every body if he or she has the characteristics or information about Dc motor that is used in train give me those information or technical characteristics .

0 Answers  

---

A 10 kva ,400v/200V , single phase transformer with 10% leakage impedance draws a steady short -circuit line current of

1 Answers  

---

---

why knee point voltage should be high in Ct for differential protection

1 Answers   NTPC,

---

i have 400/230v transformer and didnt done the neutral eatrhing. i connected one lamp to one phase and neutral to the earth. but the lamp is not glowing. again i connected neutral to earth and repeated the same. then the lamp is glowing. in the first condition i tested with a line tester also, at that time the tesrer is glowing what is happening i dont know can any one help me?

1 Answers  

---

2- What are the percentages between excitation currents in phase (R, S and T) in ∆ and Ỵ connections in excitation Current test in transformers?

0 Answers  

---

1.What is the proper definition of power system stability? 2.some times a blue spark is visible in the secondary side of a distribution transformer at the contact position of bushings and fuse wire,why?

1 Answers  

---

Compare jfet’s and mosfet’s.

0 Answers  

---

What is the difference between ground and neutral ?

2 Answers   TCS,

---

which type of capacitors using in single phase motors

1 Answers   Vishnu Infra,

---