Electrical Question: Separate 12v and 110vac

[Blue_Villain]

I'm in the last-minute design phase while I wait for my trailer to come back from being sandblasted and sealed. I'm looking for a system that will serve both a boondocker and a city-slicker alike. Short term I'm going to be running a 12v system for the lights and vent fan, long term I want to have things like a fridge and a window-unit AC. My current thought is to completely separate the two systems, attach an automotive battery charger to the 110 system that charges the 12v battery when plugged in (switchable, of course) but I'd still be able to boondock with the 12v system off the battery. The fridge and AC would just be lifeless when off-shore.

Somehow it just seems too simple. Like this is exactly what everybody else already does, or that I'm missing something terribly important.

Any ideas?

[bobhenry]

I used 12-3 extention cord for the AC and a 2 wire 14 gage for the DC that I stripped form a tossed out vacuum sweeper.
They both are in the same switch box controlling the same lamp. These switches control both Ac and DC bulbs mounted in the same fixture,



Here are the switch boxes I used a flip toggle rated for 120V AC and a rotary switch for the DC so even in the dark you can feel which one you have. The lower switchs control the little interior lanterns and the higher ones closer to the door controls the "porch" light.







P.S. you might want to take this discussion to the electrical section where it will be better seen.

[Gladtobehere]

Personally I would keep them completely separate, so as to avoid any chance/risk of 120v showing up in a 12 v circuit. The other benefit is you can service one side of your setup while the other remains 100% functional.

I only have a tiny tear so I use flashlights (led) for lighting and an extension cord for AC, shore power.

[bobhenry]

circuit breakers, GFI protection and maybe even these little 12 volt glass fuses for the 12 volt side need to be utilized.



Liberal application of a good grade of electrical tape and even shrink tubing to protect splices and connections are also good safety factors.

With these precautions used, I don't forsee the 120 volt escaping the insulation that surrounds the seperate strands and then jumping forth thru the outer insulated sheath into the 12 volt DC wire that is sheathed in multiple layers also.

[Dean in Ct.]

Hey Blue!
What you are thinking is almost exactly what I did. 110 in to a multi-outlet strip in a cabinet in the fwd end of the sleeping compartment. One outlet is dedicated to the battery charger. Another of the outlets feeds aft to the galley compartment, with a branch off to a duplex located on the fwd side of the bulkhead as I sleep. The feed aft ends in another multi-outlet strip in the galley on the bulkhead. 12 volt goes from battery to a marine fuse panel (fwd) then branches off to wherever I want. It really can be that simple. The only doo-dad I added is a solar charger for the battery and that is a direct feed so when the sun is out it is charging. So far no problems.
(Actually there is one problem but I'll start a new thread to discuss that rather than here.)
Good luck!
Dean

[markhusbands]

So I am going to assume that there is NO problem with routing your trailer turn/brake/running light wiring next to your cabin/galley 12v wiring. Right?