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Voltage drop in service entrance wire

Voltage drop in service entrance wire

Voltage drop in service entrance wire

(OP)
I was recently talking with a design tech and we were comparing Vdrop data and his calculations were quite different from mine.  I asked him how his were calculated and he said he was just using a PC based calc that someone gave him.  Not saying his are wrong but I would really like to figure out where the discrepancy is.  

Someone here willing to post a formula along with referenced data for the calculations?  

RE: Voltage drop in service entrance wire

Ohm's law, not just a good idea, it's the law.
But R is not just R, it is actually Z for voltage drop. The X:R ratio of Z may be significant and the phase angle of the I may be significant.
How about you post your formula?

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: Voltage drop in service entrance wire

(OP)
Well, that is sort of where I am at in the calculation.  I am thinking that some of these calcs have an engineered margin for PF of about .8-.9 which would certainly throw things.  All calcs would be at 60hz.  I will dig up my forumla to see if it gels.  I think I worked it from the EE law side rather than the NEC code book side which might be where the issue is.  I am not as concerned of the NEC data as much as I am concerned that I have done the correct calculation and accounted for all present conditions.   

RE: Voltage drop in service entrance wire

(OP)
That is precisely what I was looking for.  Thanks a bunch!

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