hi

if i have the load readings for R,Y,B,N phases

ex: R=209 , Y=158, B=130, N= 209
how i could calculate the percentage of unblance??

also hoe to calculate the voltages for Rn,RY,RB???

please help me

 

plz post your attempt at the question, without which the purpose of forum is defeated. also can you attach the circuit diagram because its not quite clear to
me.

 

Thanx

actually there is no circuits!!
these are all information i have pluse DT capacity is= 315 kVA
oh yah N= 52 Amps not 209

is there any way to calculate the Rn,RY,Rb?

 

Was http://en.wikipedia.org/wiki/Three-phase helpful?

 

well, i dont remember solving unbalanced load question, but somewhere i read
that power for each phase remains constant so may be 3.5/3 kva per phase, i m not sure if it applies to unbalanced situation so please check if that is the case. if it is then voltage calculation becomes easy .will get back to you if i get a some clue.
for solving problems based on unbalanced load the method of symmetrical components is used. (i myself m working on it now thanks to you ).