I realize that the diagram (beautiful, btw) is probably showing
BUT: is this setup even to code? It looks to me like the two 12-2
cables are unbalanced. You have nothing but HOT in the one (12-2 shown
on top), and nothing but NEUTRAL* in the other (12-2 on bottom). Seems
like you are supposed to have both those 12-2's in a conduit, or use a
And lastly, one of those whites (the ones in the upper 12-2) should be
relabeled as black, or red, since it is serving as a hot.
* OK -- neutral isn't quite the right way to say it. But look at the
current when the lights are on. In the upper 12-2, you have a black and
white. One will be disconnected (no current), the other will have, say,
3 amps (for 3 mongo lights!), running to the right. The lower 12-2 will
have a mixture of amps on the black and white. The first light consumes
1 amp, so the leftmost lower 12-2 will have 2 amps on the black, and 1
amp on the white, both going left. The rightmost lower 12-2 will have 1
amp on the black, and 2 amps on the white, both going left. All of this
is a no-no, isn't it?