LEAD LAG question

[Toilalong]

For Load, Motors, Generator
lead PF = negative Q ; lag PF = positive Q

But sometimes when I do practice problems I see some places claim lead PF = positive Q ; lag PF = negative Q for Motors and Generators.

I'm confused, any help to clear things up a bit will be greatly appreciated.

-Thanks,

 

[KatyLied P.E.]

See my answer in the "anything about PE Exam" section where you posted the same question. Hope it helps

 

[KatyLied P.E.]

I believe it's a matter of which convention you choose. GA Tech's PE prep course's convention is reactive power that is capacitive (leading) is negative while inductive (lagging) is positive. Their course specifically uses the phrase "by our convention" so evidently other sources choose differently. I like to think of it in terms that the electrical system is by default inductive and I then equate "positive" to that. Capacitive acts as a "negative" to that to correct the PF. That may sound kind of strange but it helps me understand.

I'd think the important thing is to stay consistent whichever convention you choose. also the problem would most likely indicate which convention you should use for that case.