Which conductors are they, because you may be under that wonderful 156% rule that makes wires get really big really fast.
What you do not want to do with PV conductors is scrimp on conductor size because you can. Make sure you check all of your voltage drop calculations and keep a running tally of where you're losing performance. Because if you don't, you may find yourself in trouble with any performance warranty you have.
156 percent rule?
The 125% required twice by 690.8.
You can still use the 90? ampacity for derating.You want to keep in mind that even though you're using -2 90*C conductors, many of the terminals in PV systems are listed for 75*C so keep that in mind for your derating.
And if it is #6 or smaller you can't re-identify it...you must use white or gray.Another common mistake I see installers make using USE-2 and PV Wire is that they neglect to re-identify their grounded conductors.
You can still use the 90? ampacity for derating.
And if it is #6 or smaller you can't re-identify it...you must use white or gray.
I wonder if my instructor caught that. Just to be sure, (A) (1) takes us up to 125 percent and (B) (1) takes it up that other 125 percent (1.25^2 = 1.5625), correct?
That is my understanding.
I designed a couple of 500 KW systems and as Tall Girl points out the wire sizes get big fast by the time you do the 125% + 125% and the ambient / on the roof derating.
You are correct, I missed that. It is 200.6(A)(6) in the 2011 code.200.6 (2) seems to allow an exception for single conductor cable in PV systems. It says all we have to provide is 'distinctive white markings at all terminations'.
You are correct, I missed that. It is 200.6(A)(6) in the 2011 code.
Of course, the key word is 'distinctive'. I wonder how many PV installers get gigged because their marking fails to have a special style, quality or attractiveness?
We're talking about men, here. A length of white tape or heat shrink is plenty "distinctive".
Now, if it were women doing the installs, they'd have pretty ribbons and maybe some glitter and everything would smell nice.