Wiring a Classic DC electric potential

[Photowhit]

Well I'm through with my rigged up E-panel and I'm cleaning things up...

Since I only have a potential 40-50 amps coming into the Charge controller and 90 coming out of the controller is it OK to run # 6 into the controller on + PV and #4 out to the battery bus? What about the negative side?

While I'm here, I have some #4 thhn and would like to run it in from the array, into a 50 Amp Din rail breaker, the Breaker is rated for #6, #4 seems to fit, I had intended to strip off a few strands and shrink wrap but it appears to fit fine. Vic from NAWS(and here) suggested it's a problem of rigidity. I'm trying to do 3 Classic(lites) into a lite E-Panel. I had intended to take #6 to the CC from the breaker and #4 out to the 90 amp panel mounts.

Am i nut's? Is there a plate for the side of an E-Panel lite that has din rail in one and panel mount on the other, actually prefer Panel mount on top and the din rail below (thinking of switching the Din rail breakers this way for wiring runs, bringing in the PV feed through the back 1" at top)

Hope I'm making sense, it's been a long day.

[boB]

Well, if using a single negative wire to the negative bus bar in the E-panel, that negative wire
carries the difference from input current to output current.

So if you have 90 amps output and 50 amps input, the negative wire carries 40 amps.

Don't know if you needed to know that but that's how that works.
Maybe Ryan can answer the rest of the question ?  Or me, tomorrow.

boB

[Halfcrazy]

The Negative from the Epanel would need to be #4 to meet code simply because the positive is breakered at 90-100 amps.

Ryan

[Photowhit]

Thanks Ryan and boB,

So my runs to the Classic will be #6 in from PV, #4 out to Battery bus and #4 to neg bus. Wonder what my clamp meter will show on the negative side? Just the 40 Amps?  (or difference, I'll likely never fill out my array, 2000 watts/@60V input for now)

I do understand I'll likely rarely see the current 30+ Amp input potential.

Your awesome! and keep late hours too!