ALLInterview.com :: Home Page            
 Advertise your Business Here     
Browse  |   Placement Papers  |   Company  |   Code Snippets  |   Certifications  |   Visa Questions
Post Question  |   Post Answer  |   My Panel  |   Search  |   Articles  |   Topics  |   ERRORS new
   Refer this Site  Refer This Site to Your Friends  Site Map  Bookmark this Site  Set it as your HomePage  Contact Us     Login  |  Sign Up                      
Google
   
 
Categories >> Engineering >> Electrical Engineering
 
 


 

 
 Civil Engineering interview questions  Civil Engineering Interview Questions (3073)
 Mechanical Engineering interview questions  Mechanical Engineering Interview Questions (3287)
 Electrical Engineering interview questions  Electrical Engineering Interview Questions (13323)
 Electronics Communications interview questions  Electronics Communications Interview Questions (2364)
 Chemical Engineering interview questions  Chemical Engineering Interview Questions (416)
 Aeronautical Engineering interview questions  Aeronautical Engineering Interview Questions (77)
 Bio Engineering interview questions  Bio Engineering Interview Questions (17)
 Metallurgy interview questions  Metallurgy Interview Questions (79)
 Industrial Engineering interview questions  Industrial Engineering Interview Questions (163)
 Instrumentation interview questions  Instrumentation Interview Questions (2375)
 Automobile Engineering interview questions  Automobile Engineering Interview Questions (106)
 Mechatronics Engineering interview questions  Mechatronics Engineering Interview Questions (38)
 Marine Engineering interview questions  Marine Engineering Interview Questions (43)
 Power Plant Engineering interview questions  Power Plant Engineering Interview Questions (75)
 Engineering AllOther interview questions  Engineering AllOther Interview Questions (1196)
Question
HOW TO CALCULATE THE CAPACITOR RANGE FOR LOAD FOR PF 
IMPROVEMENT?
EXPLE:FOR 65 HP LOAD HOW TO CALCULATE CAPACITOR RANGE?
 Question Submitted By :: Electrical-Engineering
I also faced this Question!!     Answer Posted By  
 
Answer
# 1
Boss what if u dont have the table?

let Cos(@1) be the present PF

@1=cos'(@1) (cos inverse)
let Cos(@2) be the desired PF
@2=cos'(@2) (cos inverse)


KVAR required= KW[ tan(@1)-tan(@2)]

for 65 Hp load
KW= 65HP*0.746 = 48.49KW
Considering Preent P.F=0.50
desired pf =0.99
ie cos(@1)=0.5
@1=cos'(0.5)=60
@2=cos'(.99)=8.1

kvar=48.49*[tan(60)-tan(8.1)]
=48.49*[1.732-.142]
=77.08

kvar=77.08
 
Is This Answer Correct ?    48 Yes 3 No
Deepakindi1
 
Answer
# 2
Capacitor range is actually given in Kvar, so to find that
range in kvar

As we know
Power factor = KW/KVA
for 65 Hp load
KW= 65HP*0.746 = 48.49KW
Considering Preent P.F=0.50
Target pf =0.99
Multiplying Factor by standard table= 1.59
Kvar= 48.49 KW * 1.59 = 77.09 Kvar

hence for the load of 65hp, capacitor range will be 77.09
Kvar.
 
Is This Answer Correct ?    64 Yes 23 No
Mahesh Sonawane.
 
 
 
Answer
# 3
please mention the existing powerfactor.... 
Is This Answer Correct ?    28 Yes 9 No
Bala123
 
Answer
# 4
as pf not giving ,taking pf 0.8
let pf of load =0.8
kw of load= 65 hp=65*0.746=48.5kw
kva =48.5/0.8=60.625kva
kvar =sqrt(60.625^2-48.5^2)=36.375kvar
if we want to improve pf to 0.95 then
improved kva= 48.5/0.95=51.052
improved kvar= sqrt(51.052^2-48.5^2)=15.9411
requard capacitor range = 36.375-15.94=20.43kvar.
 
Is This Answer Correct ?    24 Yes 10 No
Girish Kumar Samal, Hindalco,h
 
Answer
# 5
first we should calculate the load(inductive or capacitive
or resistive).
in case of resistive load-----
in case of resistive load the, actual power factor will be
01(maximum),in this case the voltage will linior with
respecte to load current.
so tatal resistive load is(in example 65 hp),
so total load in kw = 65*0.746
=48.49.
As we know
Power factor = KW/KVA
for 65 Hp load(if pure resistive)

Considering Preent P.F=1
Target pf =0.99
Multiplying Factor by standard table= 1.56
Kvar= 48.49 KW * 1.56= 75.64

hence for the load of 65hp, capacitor range will be 75.64
Kvar.(in pure resistor).
 
Is This Answer Correct ?    2 Yes 2 No
Naveen Kumar Mishra
 
Answer
# 6
let us conside current p.f = .8 & improved to .9,
Load = 65 hp =65 * 746 = 48.49 KW
KVA1 = 48.49/.8= 60.61

KVAR = Squareroot of [ square(60.61)-square(48.49)]=36.36
KVA2 = 48.49/.9= 53.88

KVAR = Squareroot of [ square(53.88)-square(48.49)]=23.49

Increased Capacitor bank capacity = 36.36-23.49 = 12.87 KVAR
 
Is This Answer Correct ?    0 Yes 0 No
Manish Deswal
 
Answer
# 7
In This case no other detail is given except the power
rating .

Therefore pf=( KW/KVA)
In order to get incentive and good power factor it is
required to maintain power factor above 0.95

So we take pf=0.95 and kw=(65*0.746)=48.49
Therefore KVA= 48.49/0.95 = 51.04

We know that KVAr= Squareroot( (KVA)^2-(KW)^2)


Therefore KVAr = sqrt(51.04^2-48.49^2)

=15.90 approx..


Capacitor required = 16KVAr.
 
Is This Answer Correct ?    8 Yes 10 No
Chandru
 
Answer
# 8
power factor is not mention so how can calculate ........... 
Is This Answer Correct ?    4 Yes 6 No
Ram Lal
 
Answer
# 9
MR. girish
What is meaning of sprt and that calculation
 
Is This Answer Correct ?    5 Yes 8 No
Sudhakara
 
Answer
# 10
mr
Deepakindi1 iwant to know what the maximum range of mccb
 
Is This Answer Correct ?    3 Yes 6 No
Sivananda Samantara
 

 
 
 
Other Electrical Engineering Interview Questions
 
  Question Asked @ Answers
 
wt wil happen if a 120kv line is grounded   4
What is the importance of creepage distance in disc insulator ?   1
what is O.T?specify the acceptable range?   2
what is the power factor of an inductive load ? (i) Zero (ii) Lagging (iii) Leading (iv) Unity   5
Is your generator is automated or manual if so do you know the circuits? RRB 4
Is possible to increase the voltage without using transformer? why?   9
What conditions are required for a transformer to operate at low frequencies ?   1
What is drain current of static relay?   1
when turbine trips generator will becomes induction motor or synchronous motor? JSW 4
how many amps in 1KVA?   11
How to calculate Battery back up time for a 400 AH Battery bank having a load of 20 Amps and charging time required to fully charge this battery bank?   2
Why the suply frequency in INDIA is 50HZ HCL 5
 
For more Electrical Engineering Interview Questions Click Here 
 
 
 
 
 


   
Copyright Policy  |  Terms of Service  |  Articles  |  Site Map  |  RSS Site Map  |  Contact Us
   
Copyright 2013  ALLInterview.com.  All Rights Reserved.

ALLInterview.com   ::  KalAajKal.com