Wiring Diagram Help Please

[daneb]

Hello again,

I posted not too long ago about wiring my trailer and I have done some research since then about possibilities for my trailer electrical system. I have decided that I am going to use two marine deep cycle batteries for DC power and connect them to an inverter. The inverter will be connected to an automatic transfer switch so that I can switch between batteries and shore power. On my AC circuit I will also connect to a battery tender/charger so that when I am connected to shore power I can constantly charge my batteries. I have several questions about this setup and have included a schematic.

1) Will having my Battery charger hooked to my AC circuit cause any problems when the AC power is coming from the batteries through the inverter?
2) How do I ground my system? I am not sure if I can put both AC and DC leads on my ground block.
3) How do I charge the battery from my car battery when driving? How would this affect my schematic?
4) If I decide not to use an automatic transfer switch, how do I switch between inverter and shore power, and how do I wire more outlets from the two on the actual inverter?

Thank you for taking time to look and answer any questions. At this point I am getting fairly frustrated with the lack of resources and examples when I do searches online that are similar to what I am looking at hooking up, so any feedback is much appreciated.

[MtnDon]

1. The battery charger AC input must be connected to the shore power line before the transfer switch. No other place. You don't want any chance of having the charger run off the inverter AC output as that is simply a vicious circle that would discharge the battery.

2. The AC bare wire or green wire ground should be connected to the trailer chassis, metal conduit or metal boxes if metal is used. The DC negative can be treated as a ground and as such can also connect to the chassis. The AC hot (black), AC neutral (white) and DC positive should never meet.

3. There are some topics here that cover that. Here's One. There are downsides due to TV and trailer battery differences in capacity, states of charge, wire sizes, back feeding (trailer to TV) issues, etc. A unique method that gets around most, if not all of the downsides of doing it the simpler way.

4. Using an auto transfer switch makes life easier and can help prevent mistakes that could be dangerous or costly if not just confusing.

5. It is best to run the DC negative wires back to a buss as illustrated, but having the buss connected by wire to the negative battery terminal. In other words don't use the frame/chassis as the negative wire. Many problems with DC trailer circuits can be traced back to using fame connections as the negative DC conductor. Best to head those off and run two conductur DC wiring for all devices.

[GerryS]

It's obvious, but don't forget fuses on the 12 volt devices either....

[OverTheTopCargoTrailer]

Not sure what kind of equipment you are using, but my Outback & Magnum do all the ac switching in auto mode. They also charge the batteries and supply ac at the same time.

Cheers ottct

[jerrybutler]

Question, if the 110 volt system is completely isolated from the frame of the trailer, what is the benefit of connecting the 110 ground to the trailer frame? If you are using electricity in the galley and standing on the ground, doesn't the ground fault breakers protect you? Just wondering......

[H.A.]

.....

[jerrybutler]

Thx H.A. I was concerned potential water entry points. While reading your post, a simple solution came to light. If I drill thru the wood floor and into the frame, I can connect the bare wire ground lug bar to the trailer frame. Not hard! Thanks again.