# star connection

Discussion in 'Homework Help' started by segecious, Nov 7, 2014.

1. ### segecious Thread Starter New Member

Nov 6, 2014
7
0
I have a problem solving the following assignment question.
A star-connected balanced three phase load 30 ohms resistance per phase is supplied by 415 v, three-phase generator of efficiency 90%. calculate the power input to the generator.

2. ### segecious Thread Starter New Member

Nov 6, 2014
7
0
i need solution to that question.

Apr 26, 2005
3,399
1,218

Apr 26, 2005
3,399
1,218
5. ### WBahn Moderator

Mar 31, 2012
18,085
4,917

What power is delivered to a balanced, start-connected load if each phase has a load resistance of R and the three-phase power is 415 V? What assumptions do you need to make, or what additional information do you need, in order to answer that part of the question?

6. ### segecious Thread Starter New Member

Nov 6, 2014
7
0
Vph=415/√3=239.6

V=IR

Iph=v/R = 239.6/30=7.99

VL =√3Vph

Vph=239.6/√3=138.3

IL=138.3/30=4.6A

p=3*I2R

=3*4.62*30=1917w

this is what i got please assist me

7. ### WBahn Moderator

Mar 31, 2012
18,085
4,917
Why are you dividing the voltage by sqrt(3) twice?

Nov 6, 2014
7
0
thanks