Classic 400w system panel wiring

I recently got all my parts for the “Classic 400 watt” system Will recommended on his website and ran into a problem yesterday when I went to install the panels on the roof and wire them together. With the combination array of series and parallel, or in group series, you need to connect the 1st and 3rd panel and the 2th with the 4th. However, with the Renogy Z brackets for mounting on the roof the panels have to be 2-3 inches apart and the cables on the 1st/3rd & 2nd/4th do no reach.... they’re only a couple inches short, but don’t quite make it. I thought about staggering the panels so the brackets wouldn’t be lined up and you could get the panels closer, but then I can’t get at the bracket screws for mounting or sealing. So, my question, has anyone had this problem with the Renogy panels? I don’t know if they shortened the cables since Will made his videos or if that’s the way they’ve always been. Has anyone bought additional mc4 extension cables just for those few inches or just scrapped it and went with a full series or parallel configuration? Thanks a ton for any suggestions!

You can make extensions as long as you need them to be. Order some MC4 connectors, wire and an MC4 crimp tool. Or just buy extensions if you can find them.

Edit: lol... I shouldn't have said 'if you can find them'. They're all over the place, pick a vendor.

Thanks Rider, I figured that may be what I have to do, was just hoping to get it done today and not have to buy more parts and wait for them and if somebody said they went with a straight series or parallel array for a van on the road and had no issues maybe I’d do that, but the In Group Series combo seems like the way to go. These conversions are full of curveballs!

Cheers!

Yup, I had to make jumpers to join the sets together. Concerned because this adds another possible point of failure. I may go back up there and make butt end splices with heat shrink.

Good call Tom ? Thanks man, I think I’ll go that route as well.

Not necessary. The MC4 connectors are fine, watertight, secure, low loss. If they were a fail point to be so concerned about, they wouldn't be used on every panel, every combiner box, etc......

Besides, if you cut the MC4 connector off of the panel wire, you violate your warranty.

Ahh ya, good point there!