How to connect a converter to existing 12V circuit?

[digimark]

My CT has a 12V battery, dome lights and a 7-pin hitch plug. At the moment I have a Battery Tender Plus attached to the battery's terminal posts to recharge the battery. I want to add a WFCO 9835 converter to the system to provide additional 12V current and save the battery when hooked to a shoreline.

The WFCO has a positive terminal, a negative terminal and a grounding point. To install it, do I just run a thick gauge black wire to the negative battery post, and a thick gauge red wire to the positive post? Where do I run a ground wire to?

Thanks in advance. -Gary

[Nobody]

Your trailer battery should already be connected to a 'Distribution Panel/Power Center' that provides DC voltage to your dome lights and/or any other DC appliances. You need to connect the WFCO 9835 to the positive & negative 'bars' of the distribution panel & then on to the battery. That way your battery will 'draw' whatever charge is needed when connected to shore power, & provide needed DC power when off grid. Actually, if the current battery connection to the distribution panel is of sufficient size you probably only need to connect the new converter to the panel, otherwise depending on length of 'run' I'd replace the current battery/panel wires with new wire of proper size, & use same wire for connecting the converter to the panel. Here's link to a manual for the 9800 series converters -

http://www.wfcoelectronics.com/documentation/manuals/Manual%20-%20WF-9800%20English.pdf

[digimark]

Thanks for the reply, but my Pace-American trailer doesn't appear to have distribution bars. (I would have thought a brand-name trailer would have done this better, but...)

There's an electrical box attached to the frame where the wires come together. I took off the cover and this is what was there -- everything tied together with wire nuts! I suppose it works, but not very flexible.





Any thoughts? I'm not sure I could add another wire to each of the pos and neg wirenuts. Thanks.

[Nobody]

I think I'd 'ditch' that setup. I'd go to Radio Shack & pick up a couple of terminal strips with at least 4-6 connectors on each. Also some kind of 'pass-thru' to bring the wiring into the trailer. Find a spot inside to mount the terminal strips & the WFCO 9835 where the electrical cord from the converter will be accessible. Bring your wires from the dome lights & any other 12vdc circuits to the terminal strips (use one strip for positive & one for negative). Connect the positive wires thru an inline fuse to one terminal strip & negative wires to the other. Connect the converter & battery the same way. I'd have the converter connected at one end of the terminal strips & the battery at the other. You can run a 'ground' wire from the Chassis (Earth) ground lug of the converter to the trailer chassis if you want. A better system would be to use fuse blocks (also available at Radio Shack or auto supply stores) in place of terminal strips so each 12vdc circuit would be protected.

[dh]

Not ditching your system, but I'd start fresh. Connect all you devices to the WFCO via terminal strips as stated above. Then make your 110v connection to the WFCO, and run your two 10g wires to the battery, and you should be ready to go. The WFCO is nothing like a battery tender, it will actually power your 12v devices when 110v is available, not just float a charge on the battery. In reality, the WFCO will even power the 12V if there is no battery at all.

[Shadow Catcher]

There is a seven terminal waterproof box that is being used in our MM this has screw posts. Purpose built for this. Found it on ebay have seen it since elsewhere. you will need a fuse panel both 110 and 12V
http://www.wfcoelectronics.com/document ... nglish.pdf

[dh]

Doesn't the wfco have an integrated breaker box? Also a few around here use no more than a power strip for this, look at caseydog's bare minimum AC sticky.

[digimark]

The WFCO 9835 has only a positive and negative terminal, and a chassis ground point.

Conceptually I can see that distribution bars form a more elegant and reliable connection for all of *that* without using wirenuts, but I'm sure I'd rather have it all installed inside the trailer mounted against the front wall under the counter, than try to install blocks on the trailer frame or underneath the trailer/exposed to the elements. Which means I need to bring the wires inside the trailer.

Anybody know a good electrician?

EDIT to add this: The trailer has a 12V roof fan, two overhead dome lights and two 12V power points -- the circuits all run back to this box, and then the battery and the hitch plug... There's the three white wires nutted together, and the thick red wire and two black wires nutted together. There's a red and yellow wires nutted together, and green and brown wires connected. Then there's one red wire connected to a light-blue crimp connector by itself, and another yellow wire on its own crimp connector by itself. I'm guessing these are to prevent short circuits?

I just can't imagine how to bring this mess back inside, connected to barrier strips, and adding the WFCO to it. Maybe I really do need an electrician.

Another EDIT: OK -- looking at a trailer wiring diagram and my actual trailer wiring --

RED -- left/stop/turn signal (connects to trailer yellow)
YELLOW -- (open)
WHITE -- ground
LT. BLUE -- (open, electric brake signal)
BLACK -- positive 12V
GREEN -- right/stop/turn signal (connects to trailer grey)
BROWN -- tail/license/side marker lights (connects to trailer green)

I can see that, whatever the method of connection (bigger wirenut or barrier block), the red positive connection on the WFCO should go to the red/black/black wirenut, and the negative pole on the WFCO should go to the cluster of three white wires -- and I should run a wire from the WFCO chassis ground to a screw on the frame?

With the converter, battery and TV power all hooked together, am I going to start a fire, or does it all just work?

[dh]

It all just works

Now I wouldn't leave the TV running and hooked up (electrically) to the trailer, and plug in power to the WFCO at the same time...

[digimark]

He timidly asks,

"What would happen if the TV is electrically attached to the trailer wiring, when the converter is plugged in?"

And would my car insurance cover the damage?

[Shadow Catcher]

Then it would bring the TV battery up to full charge, might actually do it some good.

[S. Heisley]

Gary:

From what I've found, most electricians and RV specialists won't touch a home built or altered trailer.

Here's an idea for you:

This is just a guess, but, looking at your pictures, above, it seems that you might be able to add a second like-sized wire box side-by-side, next to the existing one, either the way it is or by turning both from horizontal to vertical positioning. (I might try the latter.) Then, you can bring all the positive wires in one box, on a terminal buss and all the negative in the other, on a ground buss. That way, you'd have just one positive wire coming out of one box and one negative wire coming out of the other box, going to your battery and maybe just a few added incoming wires from the converter.

Assuming your converter allows for AC, instead of hard-wiring your electronics, if you add an AC outlet (make sure it is a GFCI outlet), you could just plug your video player or whatever into that when you are on shore power. (I don't believe that using the AC outlet while charging effects your converter or battery.) That way, you could unplug your electronic gadgets and hide them away when you aren't around. For AC, the way mine works, the green ground wire goes from the converter to a ground screw on the chassis and the AC outlet wires (positive, negative, and ground) go directly from the outlet to the converter without going through the busses except at the converter.

Knowledge:

I don't know if you are new to this kind of wiring or not; but, if you are, may I suggest you get a good book and sit down and read it. I recommend Managing 12 Volts by Harold Barre. That one is usually found at good RV supply stores. Also, use the toll-free Cheng USA, Inc. Tech Support phone number to get help when you get in a bind. (1-877-294-8997)

Buying Electrical Parts:

Try the big box stores but, if you can't find what you need there, you can usually find it at an ACE Hardware store, in small quantities.

[dh]

Then it would bring the TV battery up to full charge, might actually do it some good.

On second thought, you are probably right, I wouldn't worry about it.

[digimark]

I called the WFCO support number Sharon gave me (877/294-8997) and talked to a pretty helpful guy named John. He walked me through the install, basically run one wire from the negative terminal to the group of white wires, another wire from positive to the black/red wires, and drill a hole in the frame, and run a third wire with a ring lug to it from the chassis ground to the frame. He said to scrape the paint off the frame first, then drill a hole and secure the ring-lug to the frame. He said I should spray over the ring lug with a silicone spray or rubber compound to protect it.

He also confirmed that all three power sources (battery, converter and TV) can be connected together and things should be fine -- just make sure I have a solid connection because the biggest danger is a poor connection causing arcing, building up heat and leading to a fire.

Thanks to everyone, especially Sharon, for your help. -Gary

[Nobody]

Yep, that'll work but, I believe you're gonna need some bigger wire nuts & you still ain't 'fused' unless there're fuses somewhere else in the system.