I finally found time to re-design my panel and string combiners The new panel combiners will go in a pinfox
box with the plugs on the sides and the meters on the top. I may add a smokey plexi sheet on top to improve
the readability of the meters in sunshine. The powerpoles aren't exactly waterproof, but I CAN use hot
glue to seal up the meters and also seal the powerpoles to not allow water into the enclosure. It will still
be possible for water to find its way into the contacts on the outside, which isn't great, but this will be
a huge improvement over the exposed "slab" mark 1 design. The pinfox boxes have a gasket seal on the lid too.
The string combiner is being designed with a little future-proofing in mind. I currently have four strings,
but this combiner will have enough jacks to support up to six strings. I'll be using a larger pinfox box,
since that big meter I've been using takes up almost all available space inside the smaller boxes. This will
also give me enough room inside to add a fuse on the output. All six input jacks will be wired in parallel.
My strings can produce at most 5 amps each, and since I currently only have four of them I will leave the fuse
at 20 amps. While adding more strings will exceed that max, that's the limit of the meter so 20 should be ok.
The powerpoles can be marginally waterproofed, but the bigger concern will be the large meter on the string
combiner. I think I can get the screen waterproofed, but it's got a tac switch for resetting the watt-hour
count, and I'm still thinking on how to waterproof that, because that will send water directly onto the
meter's circuit board.
I have since installed a 6 amp schottky in all six combiner boxes, to isolate panels from each other when they
are connected in parallel by one of the string combiners. I also went through the painful process of replacing
all the red and the dim green meters with bright green meters. It was worth it, they're all looking great now!
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