Looking for some electrical/fuse advice

Ok.. I have a plan for the upcoming build session and I was wanting your opinion. My plan is to mount a 12v panel in the bed of the truck, utilizing the small storage bin and building it into the door. This seems to be a common method people do. Alternatively, I am going to try and remove the entire small bin/110 outlet in the back, so that I can reach in above that section and mount my panel directly into the wall of the bed, thus keeping my storage bin useful. Here is what is going into the bed:


I was thinking that in the cab, on the passenger side of the center console, I could mount this setup as an extra for long road trips and such. This would also make it easy to charge laptops and what not while on the move.


I already have both panels, all my wiring and equipment, so I should be good to go with this build. I am going to run them into my bluesea fuse box, but I honestly don't know what size fuse I should be using for these.


This will be operating off of the accessory battery, which is in turn going to be assisted by the solar panel setup that is going up at the same time, so I want to make sure that my fuses are accurate and I don't risk any of the equipment. Thoughts?

 

Off the top of my head, there are four factors when sizing any fuse:

1-What is the current limitation of your source??
(For example, fusing a solar panel that can only provide 5 amps with a 25 amp fuse does not protect the source. Another example is a sub-panel fed with a main 20 amp fuse, can’t power a branch circuit that requires a 40 amp fuse)

2-What is the gauge of wire you are protecting??
(For example, protecting a 16AWG wire with a 40 amp fuse will allow that wire to catch fire before the fuse ever blows during an overload or short)

3-What is the expected load current??
(To minimize wire size, and maximize safety, it makes sense to fuse loads at their specified rating and no more. For example, don’t fuse a 7 amp fog light at 30 amps etc. Also be sure to use all the downstream loads that might be the on at any one time in calculating your fuse size)

4- do you need to account for inrush currents??
(Some loads, like pumps, other motors, and some inverters etc, draw an excess amount of current when first turned on. In these cases you may need to oversize the fuse to prevent it from blowing on start up)


Hope this helps!

 

I think I am understanding what you are saying:

1) The solar panel will be running through a solar controller and into the accessory battery, and then my accessories off of that. The solar won't be directly running power to any accessory.

2) I am running 8 gauge wire to both sources, one into the cab and one back to the bed. I am going to have to figure out what size fuse is needed for this protection.

3) As far as the load current. The panel in the cab is there to charge laptops, phones, and other small stuff. The panel in the back will also provide that, but I would like to be able to plug in a fridge/freezer combo down the road, and I see those (I was looking at the 50 quart ARB) are listed as using .7 to 2.3 amps per hour.

4) At the time, I don't plan on any inverters or anything else, and my pumps are straight lined, so won't run through this setup. I should be ok there.

Thank you very much for the information, I truly appreciate it.