The next step is to get the power from the house battery up to the switch panel where we can use it to do some good. Two conductors – a positive from the battery switch (with a fuse) and a negative from the ganged together battery negatives should be ran to where the central switch panel is. You should use marine grade primary wire for this.
This is sometimes a long wiring run on a boat. Plus these two conductors will carry the current of all your electrical loads combined, so they are typically fairly beefy cables. Even a small boat (3-5 loads) we’d recommend at least 12AWG wire for this. 10AWG for larger boats (5-10 loads) is normal. 8AWG is getting toward over-kill in most cases for boats under 30ft.
Remember these are all generalities, there are many valid reasons to make exceptions
Keep in mind that the longer your wiring run from the battery to switch panel is, the more voltage drop you’ll have (more about voltage drop). Prevent voltage drop by using larger cable.
The power cables will be run to your New Wire Marine custom marine switch panel and your tinned marine negative bus bar. Most of our switch panels include waterproof resettable circuit breakers with all the connections pre-made to make them work, that’s how it is shown here.
Note, if you do not order circuit breakers in your boat switch panel you’d need to insert a fuse block before the panel, then individual conductors from each fuse to each panel (we really recommend including circuit breakers in your panel if you have space, it will really make your life easier installing and maintaining your new custom switch panel).
The main house battery positive conductor will feed directly into the new switch panel. The main battery negative should go to a negative buss bar (like this one), where all your boat’s load negatives will eventually be attached.