Accessory bus and power bar

[Rita Runner]

Accessory wiring is getting crowded by the battery, so I want to consolidate it to the other side of the engine bay from the battery in my JL. So i thought i would put in two bus bars. one just a straight bus bar, going to ground, and one with fuses in it. (see attached pic). but what i am confused with is the picture (from BlueSea Systems) show the ground bar also attached to the negative terminal. Is that right? I would have thought it would just be attached to a grounding bolt in the engine bay. Second question is it shows a fuse between battery positive and the "fuse" panel bar. What size fuse should this be? The fuses will run anywhere from 10A to 30A (radio).

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[yokramer]

The ground can be any good chassis ground, it does not have to go back to the battery.

As for the fuse thats going to depend on what you plan to have on the circuit. It cant just be the size of the largest fuse in the bus, because if all circuits are running it could be over that amperage. Im sure there are calculators online or even best practices on BlueSeas site that may help.

 

[Terrymo]

Disclaimer: I’m not an expert. It’s your Jeep that’s going to burn to ground if you mess up or follow the advice of a stranger on the internet.

Total up the amp draw of all your existing and future accessories that will be on this fuse block. Don’t underestimate here. Don’t cheat and say I will never have more than x number of items on at a time.

Calculate the distance, round trip, from the battery to the fuse block and back. Plug these numbers into the Blue Sea Circuit wizard and you will get the required wire size of the main power and ground wires running from the battery to the fuse block. Based on that wire size you will see what size fuse is needed to protect the main power wire. That main fuse should be installed as close to the positive battery terminal as practical, and generally not more than about 6 inches from the battery. Blue Sea Systems has many easy to understand articles on their website to answer your questions.

 

[yokramer]

Disclaimer: I’m not an expert. It’s your Jeep that’s going to burn to ground if you mess up or follow the advice of a stranger on the internet.

Total up the amp draw of all your existing and future accessories that will be on this fuse block. Don’t underestimate here. Don’t cheat and say I will never have more than x number of items on at a time.

Calculate the distance, round trip, from the battery to the fuse block and back. Plug these numbers into the Blue Sea Circuit wizard and you will get the required wire size of the main power and ground wires running from the battery to the fuse block. Based on that wire size you will see what size fuse is needed to protect the main power wire. That main fuse should be installed as close to the positive battery terminal as practical, and generally not more than about 6 inches from the battery. Blue Sea Systems has many easy to understand articles on their website to answer your questions.

Blue Sea is legit and we see their stuff on Fire Trucks more and more.

 

[THAW]

That Blue Sea 8-Circuit Compact Fuse Block (nice little unit, I have one) has a max rating of 100 Amps, so it should be fused at 100 Amps or less. Other than that limit, it's critical to match the fuse to the wire gauge used to connect the battery to the fuse block (@Terrymo explained well how to size the wire).

Regarding the double negative/ground, perhaps the battery in the diagram represents a house/accessory battery; grounding them to the craft/vehicle is recommended.

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