What is the power ratio between power in Star and Delta
circuit?




Answers were Sorted based on User's Feedback



What is the power ratio between power in Star and Delta circuit?..

Answer / baswaraj

The power ratio between Star to Delta is 1:3

Here is the Explanation:

Let?s suppose Vs be the supply voltage per phase.

So the line voltage of the supply will be ?3Vs.

Now assume any type of load; for simplicity assume it a
only resistive load.

And let it be ?R? per phase.



For Delta connected load:



Calculation for per phase power; PD= I2R



Where I ? load current (per phase)

And,

I = ?3Vs/R {as line voltage of the supply is directly
applied to the phase of the delta load}

So,

Pd = (?3Vs/R )2R = 3Vs2/R watts per phase.

For 3 phases:

P3D = 3Pd = 3*3Vs2/R = 9Vs2/R watts.



Now for Star connected load:



PS = I2R = (Vs/R)2R = Vs2/R watts

For 3 phases: P3S = 3PS = 3 Vs2/R watts



Conclusion:

P3S / P3D = 3Vs2/R / 9Vs2/R = 1/.

Is This Answer Correct ?    26 Yes 58 No

Post New Answer



More Electrical Engineering Interview Questions

what is meant by poly phase induction motor ? how its operating by single phase or three phase?

0 Answers  


Electrical Diagram of Electric Arc Furance from transformer to Furances

1 Answers  


Why the capacitor are connected in Delta(Three Phase) for power factor improvement ?

5 Answers   Hero Honda,


oil sample dielectric test gives the insulation rupture voltage at 26 kv. is this transformer safe to be operated . The working voltage is 11 kv

2 Answers  


a 11 kv line is grounded and a 110 kv line is grounded. which line have the greater current flow?

4 Answers  






which is better ac or dc?

2 Answers  


Why Lighting transformers are used? what will be the current if lightings connected through direct raw power?

1 Answers   BMM,


How to check the thermocouple is correctly connected to cable for K type? (i,e positive pole is connected to non magnetic conductor and negative pole is connected to magnetic conductor)

0 Answers  


what is the working principle of three point starter of dc motor?

1 Answers   Ashok Leyland, Infosys, Cap Gemini, Just Dial,


What are the criteria shall be considers for sizing Fuse and MCB? If the rated current is 10Amps what should be the fuse size / MCB Size?

0 Answers  


Why carbon brushes are used in motors?

6 Answers   BARC,


Dear all i am kumaravel. now in chennai. my work is control and relay panel auto cad designing.up to 11kv to 400kv then question is i am improving my knowledge. i want some books name and auther are available for this C&R panel related. plese any one help me

0 Answers  






Categories
  • Civil Engineering Interview Questions Civil Engineering (5020)
  • Mechanical Engineering Interview Questions Mechanical Engineering (4143)
  • Electrical Engineering Interview Questions Electrical Engineering (16471)
  • Electronics Communications Interview Questions Electronics Communications (3542)
  • Chemical Engineering Interview Questions Chemical Engineering (959)
  • Aeronautical Engineering Interview Questions Aeronautical Engineering (192)
  • Bio Engineering Interview Questions Bio Engineering (95)
  • Metallurgy Interview Questions Metallurgy (336)
  • Industrial Engineering Interview Questions Industrial Engineering (253)
  • Instrumentation Interview Questions Instrumentation (2962)
  • Automobile Engineering Interview Questions Automobile Engineering (328)
  • Mechatronics Engineering Interview Questions Mechatronics Engineering (90)
  • Marine Engineering Interview Questions Marine Engineering (107)
  • Power Plant Engineering Interview Questions Power Plant Engineering (170)
  • Textile Engineering Interview Questions Textile Engineering (198)
  • Production Engineering Interview Questions Production Engineering (0)
  • Satellite Systems Engineering Interview Questions Satellite Systems Engineering (105)
  • Engineering AllOther Interview Questions Engineering AllOther (1375)