Should 12V stay grounded to the Frame?

[nunrleft]

On my build, I did not ground my 12v system to the frame at all. If you run independent 12v positive and 12v negative from the battery to the fixture there is no reason to ground the battery to the frame. You would only need to ground the battery to the frame if you grounded the fixture at the installation point and did not run a ground wire directly to the battery.

[Padilen]

I figured that 2 feet of wire and 2 terminals was affordable. I looked at my moms TT when I replaced her battery. The battery is grounded to the frame. But some DC lights are mounted on wood walls not exterior walls. There is a fuse panel for DC but I can't see above/behind, so I do not know if there is a ground/negative bar.
What I know is I tried my electrical yesterday and I have working AC and DC. And if I mount a light that grounds by base to frame it's already done.

[dales133]

From what I've found dc fuse boxes are a bastard to adapt to our style projects.
They were never designed to even come close to meeting our requirements.
Ive actualy purchased 3 different fuse boxes totaling around 120 bucks not to mention all the connectors and wiring ive changed in the process.
The major issue is any fuse box for a standard dc system is each circuit is grounded near it's location with is impossible on a foam or wood build.
You need a bus bar and/or you need one of 3 types of fuse box styles.
Single positive feed. Makes foe easy wiring but generaly no thought in design as far as placing in a position where they look tidy and the positive wires generaly enter from the front connected by spade terminals.

2 the same thing but with a negative busbar attached also as previously mentioned but if they don't have a single pos/new feed there is alot!of wiring involved.
Or there is what I reluctantly settled on witch is individually fed positive circuits fed from behind and a seperate negitive bus bar.
This I have been c hoping and changing in for months but mostly because I hate electrical work with a passion.
This option looks realy smart and it isn't that hard to make the positive side tidy but once I wired up the negative it looks crap.
But from the only side you'll see unlsess you remove the inspection pannel it Profesional looking and clean.

uploadfromtaptalk1443097245626.jpg (27.47 KiB) Viewed 963 times

You can sort of see it there and the black and red boxes are positive and negitive bus bars to help tidy up the install.

If it was a steel structure that these fuse boxes are designed for you could terminate the earth next to each conection eliminating so much work

[hankaye]

Howdy All;

I don't claim any electrical knowledge ... but,
here's a link to a series of articles by a guy that
appears to have a good handle on RV electrical
stuff, so I figure it might apply to our projects.
http://rvtravel.com/?q=category/no-shock-zone
Hope it helps.

hank

[Willuz]

After extensive research on this without a definitive answer I decided that frame grounding is just not necessary for 12v DC and in some cases can lower the efficiency of your system. I used the buss bar in previous replies for the ground and a 6 gang marine breaker panel with rocker switches to control the positive. Using 18ga solid copper home power wire the system has extremely low impedance and works perfectly.