Solar power on shore power question.

[ClydesdaleKevin]

So here's a simple question.  If I install 705 watts of solar on the roof of the RV with a Morningstar Tristar MPPT 45 charge controller, do I have to turn the solar system off, with something like a master switch at the battery compartment, before I plug into shore power?

I'm assuming the controller only feeds the batteries what they need, but I don't want them to overcharge with both the solar and Powermax Boondocker converter charging at the same time, and I don't want to harm the converter either. 

So, can I just leave the solar on when hooked to shore power and let the controller do its job, or should I turn it off before plugging in or using the genny?

Kev

[gadgetman]

leave the solar on turn the inverter off That will charge the batts faster. Watch your controller when you plug in, they solar will go to near zero.

I use a master switch for service, like you want to remove or service batteries.

[ClydesdaleKevin]

Ah, I get it...that way you don't have to unplug the solar connections when changing batteries and whatnot.  Cool!  So I won't have to keep shutting it off every time we connect to shore power at faires.  SWEET!

Kev

[ClydesdaleKevin]

So I had another idea while thinking about my solar setup.  Since I already have a 1500 watt continuous, 3000 watt max output Coleman modified sine wave inverter onboard and wired to the batteries with heavy cables, I was thinking of running a heavy gauge romex cable from the dinette compartment where we keep it, down through the battery compartment, and zip tying it to the new washer/dryer drain pipe all the way back to the electrical shore power cord/plumbing compartment, and tying it into the extra RV power plug and box I have squirreled away.

I could mount the box right next to the plug and box I installed last year for genny power, and label it Inverter, and the other as Generator. 

That would allow me to just plug the rig into the Inverter plug, reach under the cabinet in the hallway and unplug the Powermax Boondocker Converter, then reach under the dinette and turn on the inverter.

Right now we have to run extention cords from the inverter to whatever appliance or TV or whatnot we want to use.

This idea would eliminate that need, as all the AC plugs in the house would be live, while the 12 volt systems would still be running off the batteries and solar.

I would have to unplug the converter though when using the inverter like this...no need to have it running and drawing juice because it "thinks" its hooked up to shore power.

What do you guys think of this plan?

Kev

[gadgetman]

A outlet for the RV cord is the best and actually the safest way.  Yes you must unplug the inverter.

I dont have the inverter yet. Just now looking for one. I can open a door and reach the plug on mine. So I thought I would add a switch plug there. Then a wire rod/knob could run the switch. You can drill those switch levers for rods

[ibdilbert01]

Try to keep your inverter as close to your batteries as possible.    Anything 10ft and under I'd suggest 2AWG size wire to the batteries for a 1500 watt inverter.   

For the AC, keep in mind:
14 gauge is good for 15 amps
12 gauge is good for 20 amps
10 gauge is good for 30 amps

And you might want to look into auto transfer switches.  Frank and I both have IOTA-30s.  http://www.iotaengineering.com/pplib/30rman.pdf
They also make 50 amp version and you can install two like I did to automatically switch between Shore/Inverter/Generator

Also when I plug into shore power, I don't disconnect my solar controller, it senses the onboard charger and backs itself off.

[ClydesdaleKevin]

Thanks guys!  Our forward dinette bench seat actually sits right over the battery compartment, and contains the hot water heater.  This is where I put the inverter last year, using very heavy duty battery cables to hook it right to the batteries, drilling through the floor and running the cables right to the battery bank.  Its only about a 3 foot run of cable, if that. 

This is where I plan to install the Morningstar Tristar MPPT charge controller as well, since it sits very close to the batteries, without actually being in the compartment with them, and it stays nice and dry under there, with lots of airflow over and around the equipment.  I'll mount the remote Morningstar monitor panel on the outside of the dinette cabinet, right under the little digital volt meter I installed last year.

I'm going to keep the system very simple though, with just the plug setup.  The reason I put a plug in last year was because the automatic power switch blew...literally blew its metal door right off...when the genny surged.  I don't trust them...I trust the plug setup.

The cabling from the solar panels on the roof is going to drop down through the bathroom mushroom cap roof vent, down into the cabinet under the sink, then through the baseboard under the dinette table, into the same cabinet as everything else, where it will get tied into the charge controller and battery bank.  Now that is a long cable run, so I'll be using very heavy gauge cables, probably something similar to jacketed RV shore power cable.  Since it will be a thick cable, I'll wire the 3 solar panels in parellel to a waterproof junction box on the roof, so I'll only have to feed one big heavy cable down the roof vent.

Its all coming together!

Kev

[gadgetman]

I would run 1 large cable to the roof for the panel grounds maybe #2 extream size there #4 will do. Then I would run 2 10/3 cables for the pos leads. #10 is enough, even more so with high voltage panels. The reason for 2 10/3 cables is for your future panels you may run   Could use one 10/3 and one 10/2 cord too since you wont add more than 2 more panels later.


If the cable you run for the pos leads has a bare ground, ground that lead. That will act like a shielding to help noise problems, so will twisting the pos cables together.