help .. stupid question on star delta power

Thread Starter


Joined Feb 22, 2007
hi guys sorry for appearing dumb, im only a first year student....
as part of an assignment, my question reads as follows

work out the calculated value of power for star and delta conditions

i have the IP IL UP and UL values for an induction motor in both star and delta.
do i simply multiply the phase voltage by the phase current in both conditions ?( this is meant to be a simple power calc with no impedance involved ) or do the line values get involved also ?
please help i have been writing this assignment all night and my mind is melting


Joined Nov 21, 2006
The only dumb question is the one that doesn't get asked.

In a nutshell, the answer to your question is yes. The phase(winding) current multiplied by the phase (winding) voltage will yield the power in that winding.

This site has a wonderful aid to understanding three phase circuits.
Look here:
If you are still having problems, post again and we'll work it out.


Thread Starter


Joined Feb 22, 2007
thanks very much for that. yes thats what it turns out i was being asked in my asignment, but i wasnt that clear on it at all .
plus i was numbed out by hours of study ...
cheers :)