Adding DC Bus for DC Power Micro Minnie 2108DS FLX

[Ranthony]

Good morning. I want to run a small fuse bus bar inside the storage compartment of my FLX 2108DS. I'd like to have a few DC power options up there for fans and so on. Anyone with understanding on this know where to pull the power and ground from? I'd love some input/technical help with this.

[Morich]

Lots of small points get confusing when we go to terms that are not common in everyday life. Buss bars sound like one that confuses many people when it could just as easily be called a "connection"!

So what you are wanting is to add a pwer feed going to a central point where you can then connect other things! In plumbing terms, you want a manifold if techie or if talking less techie, you want a big pipe to feed a bunch of smaller pipes!

No big thing once you get past the techie terms, right?
Think of it as water hoses if those are familiar to you?
Where you want to connect will depend on what is there and what or how much power you want to feed off the new connection. Like feeding water hoses, you don't want to try to feed more water from off a small pipe than the small pipe can feed!

Many times, a buss bar is fed directly off the battery supply with cable certain to feed enough amps for anything to be added to the buss bar.
Just like wiring for the whole RV? If you want to use two air units that need 20 amps each, you have to start out with a 50 amp feed. Then when you want to feed a single outlet, you likely will break the 50 amp feed down to small like 15 amp breakers.

Beyond those basics, the location and sizing of different parts will depend on where things are now for convenience and expense in wiring plus figuring in how much power you want in total use at the end.
Generally we like to start at the battery, ad a breaker like a 30 amp and run wire to where we want to split it down, if we have some total load like 20 amp.

But there are times when we have a 15 amp circuit feeding one single oulet that we don't often use and we are only wanting to add several small item like cepll charger, or other things that need very litttle current.

You may have the same thing as a buss bar behind the desk, only we call it a power strip?? You plug the power strip into a 15 amp wall outlet and then plug 5-6 small items that may only total usp to 4 amps!
If you wanted to set an AC unit on your desk, you need to go back tot he brekaer box, but if you only want to charge a half dozen phones, the power strip is easy and works fine.
Sorry for the long winded "non-answer" but it all depends on what, where, and how much you want to do!!

As a starter, how much do all the things you would want to feed off the buss total up as watts or amps ? If you have a mix of ratings for different things, online calculators can convert them to either watts or amps.

[Ranthony]

Great answer. I only plan to run a DC powered fan on one side of the storage to exhaust the front storage when it's hot. Fan runs at 25 watts. I don't ever see getting over 100 watts total of attached devices. Again, it's just the fan that I want to run. I know running a buss bar may be overkill, but I thought why not do so if I am going to run wire.

[Morich]

Right! No need to overdo it but under is even worse!

Doing the calculator thing, I get this as being around 2 amps?


That small amount of current, even double would likely not strain many of the 12VDC circuits you are likely to find. It May help to look over the fuse or breakers to see what size most of them are but I would expect not many below 10 amp?
So that opens up several things to think over. Is the battery close by so that a simgle wire could be run straight to the battery and a small fuse holder mounted inline? That would really say any "estimating" of how much more load might be added to an existing circuit. Then whetehr to run a pair of wires like lamp cord or just a single may get into where you might find metal attached to the frame, etc as a handy place to pick up ground.
OV RV DC stuff, the frame and most any metal attached to it are often used as handy grounds to let you just run one wire back to the battery.
But then if you are going to a battery that is semi-close by and easy, it can work well to just take a pair of wires for the whole and connect both hot and ground at the battery, etc.

Kind of lots of ways, run a lot more wire or shortcuts that work just as well. Lots of the decision are things like whether it has to cross the door to get there!

Part of the problem is that we don't get any real specific on drawings for the trailer group, so we have to do more hunt and peck to get the right info!

Any chance of a light in that compartment that might have 12VDC run to it and be a handy place to tie on the back side of it? We would want to verify but lots of times there is extra current available on the light circuits for the small stuff like this.

[Ranthony]

I have a puck light in the stow compartment and there is also this bar under the stow compartment on the frame.

[Morich]

Right! If that bar is what I think I see and nearby enough to run to it, that might be my first choice as it looks like it might be a buss already to use. But that is guessing what's under the red caps!
So if you pull those caps off what do we find? I'm not used to it but might guess there is a larger wire feeding in from the battery and then small wires that may attach to some form of fuse.

I drew this up as what I'm guessing is under the caps!
Not necessarily true but somthing to look for??



What if the larger red wire is the feed for the whole thing, goes through some form of fuse as the light blue and feeds thesmall wires marked green?

I'm thinking that copper strap is the buss bar and has an extra slot if you find a fuse to match.

Or if the fuse is not handy to find, I'm betting one of those small wires will be feeding such low current that you could tie your new fan on with one of the others and be ready to go for the hot side and there is something metal close around to pick up the ground side of the circuit!
I think I see that copper strip setting on some type of black plastic to insulate it from the frame it is on, so one place to pick a ground would be to scrape the paint off around where the mounting screw/bolt is attached and stick the ground wire there!

This might be where I would just used paired wire like lamp cord as handy to run both wires for the short distance and handy stuff to attach where needed.
Maybe some crimp on spade lugs at the ends to make a nice looking attachment on the fuse, etc.