Answer / arun_sekar_1986

1.Power Factor is defined as the cosine angle between
voltage and current.
From Power triangle cosine angle is defined as the adjacent
by opposite side.
ie., cos angle=kW/kVA


2. 51-AC Time Overcurrent Relay is a relay with either a
definite or inverse time characteristic that functions
when the current in an ac circuit exceed a predetermined
value.

87-Differential Protective Relay is a protective relay that
functions on a percentage or phase angle or other
quantitative difference of two currents or of some other
electrical quantities.

Answer / gunasekaran

low P.F following effect will accure.
1.KVA=KW/PF for low PF KVA ratng so equipment size will
incress.
2.PF is low more current so transmission loss will more.and
conductor size also incress.
3. poor voltage regulation
4.M.d incress.
51-idmt o.c and earth fault
87-diffrential relay it is operating B/W primary and sec
current diffrence.

Answer / vinod shnde

Mr. arun,cosangle=adj side/hypo

A 3-PHASE TRANSFORMER IS USED TO STEP-DOWN THE VOLTAGE OF A 3-PHASE, 11KV FEEDER LINE. PER-PHASE TURNS RATIO IS 12.FOR A PRIMARY LINE CURRENT OF 20A, CALCULATE THE SECOUNDRY LINE VOLTAGE, LINE CURRENT AND OUTPUT KVA FOR FOLLOWING.A)STAR- DELTA.B)DELTA-DELTA.

0 Answers   Ispat, Red Bull,

---

How to configure the drives in PLC, through Profibus commnication. And to how to address it?

0 Answers  

---

What will happen to magnitude of voltage of other two phases if one phasw will touch the ground?

3 Answers   Construction, NPCIL,

---

Which oil can be used in transformer?

1 Answers  

---

Dear friends , I am going attend interview for WARTSILA INDIA LIMITED , power plant .Could any 1 pls send me few questions. the area i have to concentrate? please send it to mikalraj@gmail.com. pls help me out

1 Answers  

---

Write the analogous electrical elements in force current analogy for the elements of mechanical translational system.

0 Answers  

---

how the magnetic flux is said to be rotating & alternating?

4 Answers  

---

why dc supply given to ac alternator rotor

3 Answers  

---

how to find number of run for transformer & alternator secondary side? give the example.

2 Answers   Powergear, Regen Powertech,

---

How to calcualte the total number of cells required for particular UPS of some X KVA with 3 and 5 hours back-up?

1 Answers   JLL,

---

Dear Sir I am living in Jaipur Rajasthan  now I did complete my b tech degree in electrical engineering in 2012  Sir how I gate certificate of competency for electrical supervisor

0 Answers   ONGC,

---

What is the difference between Static and servo controlled voltage stablizer?

0 Answers   Voltamp,

---