Adequate fusing for 4x100W 12v parallel

[chilly]

I was planning to wire 4x100W 12v panels in parallel on an RV and find myself getting more confused as to how far I need to go with (panel) fuses. (I'm fine with the CC to battery fusing)

Intending to wire 2 sets of 2x100W panels on the roof with MC4 bridge connetors.

Each set would then have it's own dedicated wires running down inside the trailer. (2 - 40' 8awg MC4 cables cut in half for a 20' run)

Here's the hard part for me...
From what I loosely understand (very loosely), it would be adequate to fuse each of these 2 leads with a 15-20A fuse.
If any one panel shorted, it would then only eat the other panel's output (not 3 other panel's output) - and wouldn't be a problem (they have 10awg wiring).

And then I just bridge/parallel those two sets after the fuses and before the CC (near the CC).

In case you're wondering why I'm thinking of this layout - it's just seems cheaper and easier to just spend $50 on a second 20'x8awg run into the trailer rather than dealing with the hassle of exterior junction boxes, holes in the roof, and/or more exterior grade fuses or connectors. I could be wrong - but it seems simpler at minimal extra cost.

[Mike90250]

More than 2 panels in parallel requires fuses on EACH panels lead.

A 12V, 100W panel would be generally be rated at about 5.5 amps. The right size fuse would be about 8 amps. So 10A is likely the closest standard fuse. Often the label on the Panel, will have the fuse size.

Sharp208_c.jpgschuco-sp4-170-label.jpg