I am trying to design the electrical system on the trailer. I want to be able to do the following:
1) Power an LED TV and DVD player, maybe a laptop or two and a couple phone chargers. This capability should be available at all times. My calculations show that as around 175-200 Watts.
2) When shore power is available, which is rarely for our camping, I want to run the fridge on 110V. Haven't picked a model, let's call it 300W (really won't affect anything in this discussion).
3) Everything else in trailer (LED lights, water pump, CO/LP detectors, tank level system, are all 12V
and I've got a handle on.
4) I really don't want to have two separate AC outlet systems for inverter power v. shore power. My trailer is only 15' interior, and I only plan to put in 4 outlets. Also, I would rather not have to switch the TV power cord back and forth.
I plan to buy the PD4045 charger/converter AC breaker / DC fuse panel combo and probably for the battery bank a 200 amp-hour 6v system in series)
I plan to take the 110V inlet to the system from a Marinco 30A on the side of the trailer. That way, I will either just connect up to campground power if available, or when we eventually spend $500-$1000 on a generator, from it instead.
Now here's where I'm not quite sure what to do. To fulfill requirement 1, I want to install an inverter to take the power from the 12V
system and run the TV and other goodies whenever I want (inverter will be modified sine wave, 300W continuous minimum). But if I install it on the 30amp AC inlet line so that it services the converter and all the breakers, I am scared that it will create some overload loop between the converter and inverter unless I turn off the converter every time I turn on the inverter, which is annoying, and relies on human interaction for proper operation. I want to keep it as idiot-proof as possible.
So do I jumper in to the AC lines that go to the 4 breakers with parallel wires from the inverter 110V outlet, and then install some sort of giant diode upstream on the circuit at the PD4045 inlet, but after the breaker for the converter? (I think of everything in chemical engineering terms--with the electrons flowing through a check valve).
Some solutions I see are using a transfer switch or an inline inverter with one built in. However, it is hard to justify spending $100 or more on the transfer switch when I really only need a $50 inverter for my needs. And the cheapest inline inverter with AC in that I can find is over $200.
So does anyone know of any alternative options or would that diode work?
I suppose I could wire the shore power to a breaker panel with the fridge and one dedicated outlet (like over the sink for electric kitchen appliances), then the rest to the PD4045 AC inlet, but then all the other outlets would always be running off of an inverter, even on shore power, which seems plain silly.
Wow that was a lot of typing. If you actually read that all, Thank you.