Proof my RV plans....

[camelCase]

The more revisions to the plan the better things turn out. Its the changes after it's done that turn into headaches.

 

[kbeefy]

Added multiple Transfer Switches and rerouted some 110. Added Switch to Sense wire of DC-DC Charger.

 

[eXodus]

should start a tally of how many times my plans change before the system is complete

That is normal, people here helped me through 3 major revision before I started buying and putting stuff together. Now 2 years of the system running I'm at version 5 a couple small changes and nich use-cases which I didn't for see.

Your newest version looks better, you still have a inline fuse and a breaker in series for the solar panels. Doesn't hurt but are unnecessary parts and connections.

And there are no fuses between your 3 chargers and the busbar. Here it depends on conductor length and thickness if they are needed.

You might want to add wire gauges to the plan so that we can chime in if they look reasonable. At 12v you are dealing with huge current so better have enough cooper to carry it.

 

[kbeefy]

Thanks. I'm basically 'future proofing' w/ the solar fuse and the breaker is mainly for service and winterization.

I haven't labeled or decided on wire gauge yet as I'm unsure of the distances. I will update when I have a better idea of layout. Would fuses or circuit breakers be more appropriate?

 

[eXodus]

Would fuses or circuit breakers be more appropriate?

Your choice, a breaker is also a switch. A fuse is cheaper.

 

[kbeefy]

I just had a bit of a revelation... If I mount my DC-DC controller up front, next to the alternator I can get away with using the existing 4ga wire 20' to the house battery/battery buss. That will actually save a bit of work and significant expense in buying larger wiring. It also puts it even closer to the aforementioned 'boost' wire and relay that I plan on repurposing to the sense wire of the DC-DC Charger.

Solar panels arrived today.... Only big part left is the battery.

 

[Mash]

Your system looks like it will be similar to mine. I have a Class C RV as well. What does your diagram look like now? I ended up going with a charger with MPPT so it is the DC-to-DC and solar controller all in one from Renogy.

 

[Mash]

I am a beginner so forgive my naïve questions.

Why do you need the two transfer switches? My generator has a plug that the shore power plugs into does yours look different?

I also am confused by the AC-DC converter, is that a Converter Charger?

 

[kbeefy]

I originally bought (and still haven't returned) the Renogy MPPT dc-dc charger but opted to use separate units because of the 25v limit on solar input. My Diagram is still as pictured with multiple transfer switches.

My generator is quite old and does not have a shore power input. Multiple transfer switches to accommodate 3 different AC sources.

The AC-DC Charger is for fast charging the lithium battery with the generator or shore power.

If I were to purchase a newer inverter/charger (and aparantly generator) I could simplify things a bit, but I'm reusing some of the existing equipment for now.

 

[camelCase]

You can probably cut that 4 gauge cable somewhere in the middle and add some connectors. Putting the DC-DC charger close to the batteries is preferred due to voltage drop. If you have a long cable between the charger and the battery, then your DC-DC charger might put out 14.4 volts, but you could (hypothetically) get 14.0V at the other end of the wire. (I'm not doing the math here, so don't interpret these as actual numbers.)
Conversely, the longer the wire (and more resistance) between the alternator and the charger, the higher the amps drawn from the alternator.

 

[Mash]

I originally bought (and still haven't returned) the Renogy MPPT dc-dc charger but opted to use separate units because of the 25v limit on solar input. My Diagram is still as pictured with multiple transfer switches.

Makes sense about the multiple transfer switches and generator. My generator doesn't have a shore power input it is an output. When I turn my generator on, you plug the shore power cord into the outlet from the generator, so it is equivalent to plugging it into the shore power outlet.

I just purchased the Renogy 30 Amp version of the MPPT controller. My understanding that it will be 30 amp charging when only one source is feeding it. Am I understanding that incorrectly and would be better returning it to the 50 amp version? or getting a separate DC to DC charger and solar controller?

 

[kbeefy]

Ah, I see. My Generator is hard wired into the coach.

Re: Renogy MPPT... I believe that is correct, I think it also will charge via dc-dc and Solar at the same time if sufficient voltage is present.

What is your solar panel layout? That controller requires all panels to be wired in parallel so as to not exceed the 25v limit.

 

[Mash]

I don't have panels yet. I was thinking of 4 100 watt flexible panels.

 

[kbeefy]

Rigid panels are better than flexible, and last longer.

If you use a different solar controller you can run all 4 panels in series via 10ga wire.
With the Renogy combined controller you have to run them all in parallel and then a larger wire gauge after the branch connection.
If it's a short run it might not make much difference.

I preferred the higher voltage option because I can add 4 more panels (800w total) and still use the original run of 10ga wire.

 

[Mash]

For two batteries , I was thinking of only 400 watts in panels