Answer / guest

at 0.5pf Apparent power is 10/0.5=20VA
reactive power = 17.321kVAR.
At 0.8pf
APPARENT POWER =10/0.8=12.5VA
Reactive power=7.5kVAR
So we need to provide (17.321-7.5)=9.821kVAR reactive power
through capacitor to bring of up 0.8 from 0.5.
So we need a capacitor rated for approximately 10kVAR to
achieve the target.
ANS= CAPACITOR RATING 9.821kVAR (approximately 10 kVAR)

Answer / prasad damodar bhoir

kvar= kw (tan phi 1- tan phi 2)
cos phi 1= 0.5, phi 1= cos inverse 0.5= 60
cos phi 2= 0.8, phi 2= cos inverse 0.8= 36.86
kvar= 10 (tan60 - tan 36.86)= 10 (1.73-0.74)
kvar= 9.9

Answer / h salim

Load = 10 kW
cos phi 1 = 0.5
cos phi 2 = 0.8

Rating of capacitor Qc = kW(tan phi 1- tan phi 2 )

Answer / prakash g.r.

Calculation of Required Kvar

Initial or Present Power Factor =Qi,
Required Power Factor = Qd

KVAr= KW(TANQi-TANQd)

Qi=COS-1PFi = Initial Power Factor Angle

Qd=COS-1PFd = Final Power Factor Angle

Answer / ahatesham

at 0.5pf Apparent power is 10/0.5=20VA
reactive power = 17.321kVAR.
At 0.8pf
APPARENT POWER =10/0.8=12.5VA
Reactive power=7.5kVAR
So we need to provide (17.321-7.5)=9.821kVAR reactive power
through capacitor to bring of up 0.8 from 0.5.
So we need a capacitor rated for approximately 10kVAR to
achieve the target.
ANS= CAPACITOR RATING 9.821kVAR (approximately 10 kVAR)

Answer / nagesh.patwari

Kvar = KW * [ tan (cos^-1* Current PF) - tan (cos^-1* Required PF)]

Answer / lohith

kvar=kva*sin

Answer / rk

How did you Calculate Apparent Power=20VA to Reactive power 17.321 KVAR simlarly 12.5VA to 7.5KVAR As the formula is KVAR=KVA/KW

Answer / nag

unity powerfactor

one electromagnet is called

0 Answers  

I HAVE A INCOMING 100A MCCB TPN 25KA, CABLE LENGHT OF 80M 70MM CABLE SIZE FROM MAIN SUBBOARD TO NEW DB.BASE ON THE FAULT LEVEL SETTING OF 45KA.I WOULD LIKE TO FIND OUT 25KA ENOUGH KA. APPRECIATE IF SOMEBODY CAN ASSIST ME WITH FORMULA FOR THIS. FRM: JEFF

0 Answers  

Can 60 Hz transformer be used inplace of 50 hz transfromer?

1 Answers  

For DG or Transformer body earthing, is it necessary to terminate the earth bus to earth pit directly? If not terminated to earth pit directly in earth pit and connected to any common bus strip which ultimately connects to earth pit, what will be the pros and cons?

1 Answers  

1) What are your personal strength? 2) What are your personal areas of improvement? 3) What are your expectations from from a particular job? 4) what are your carrier objectives?

0 Answers  

Without seeing the nameplate descriptions of a rotating machine,Is it possible to say which one is a motor and which one is a generator? How would you certain this?

3 Answers  

We have AC-transformer 110/13.8kv,40MVA.If DC-Voltage=110kv is applied in its primary what will happen?

6 Answers  

hi if anybody got model questions for cpcl Grade'A' electrical engineer position.send it to my mail please krishkumar22@gmail.com

0 Answers  

i have dry type transformers can you help me that how many tests i can do to know the performence of transformer and also please tell me about the BDV test and Insulation resistance test in oil cooled transformers

4 Answers   Hyundai,

what is the defination of 'Mass' & 'Weight'

3 Answers  

what is mean by unity power factor?why are u calling Resistivity load also unity power factor?

2 Answers  

what is meant by transformer oil temparature

3 Answers   Vijaya Bank,