Need help to power RV DC and GFCI outlets only.

[AustinMilt]

I want to add solar to my travel trailer. I only care to power the things that the battery currently powers when off shore power (see attached) and the outlets. What I am unsure of is how to set everything up such that I can power those things off battery bank when not on shore power, but power everything on shore power when that's hooked up. I also want to be able to charge my battery bank when on shore power. I'm concerned about winding up with a loop that drains my bank, or worse.

I think what I need to do is put an inverter/charger between the battery bank and the GFI breaker. But I don't know what to do about the existing power converter /charger.

Any advice is greatly appreciated.

 

[grizzzman]

If you want simple and foolproof Leave the MAIN and GFI breakers on and turn off the rest. Plug your RV cord into the inverter (You will need an inverter for 120 power off the battery). When on house power plug the RV cord in and turn on all the breakers.

 

[John Frum]

Here is an alternative that powers everything except your converter.
Disable the converter as it would make a power loop with the inverter/charger.
Get an inverter/charger and connect the ac side and dc side as follows
eg = equipment ground

ac {
    pedestal->inlet->surge_protector->inverter_charger->master_breaker
}
dc {
    pos {
        |<->battery.pos
        |<->inverter_charger.pos
        |->dc_panel.pos
    }
    neg {
        |<->battery.neg
        |<->inverter_charger.neg
        |<-dc_panel.neg
        |<->inverter_charger.eg
        |<->chassis_bond
    }
}

 

[chrisski]

If you want simple and foolproof Leave the MAIN and GFI breakers on and turn off the rest. Plug your RV cord into the inverter (You will need an inverter for 120 power off the battery). When on house power plug the RV cord in and turn on all the breakers.

I did my build this way. THe circuit breakers I shut off were Airconditoner 1, Air Conditioner 2, and Converter. This allows GFCI outlets and the other two non-GFCI outlets I have Along with an AC run ceiling fan.

It’s really as hard as finding a place to put your batteries and inverter and how to route it from the ceiling. I built my battery pack by the one that came from the trailer so I simply hooked 2 AWG cables to where the old battery went into the system. 4 Golf cart batteries, slide out tray, power boards with 3 SCCs, an Inverter, Busbars, and fuse box and fuses took up one side of my pass through compartment three or four feet deep.

 

[AustinMilt]

If you want simple and foolproof Leave the MAIN and GFI breakers on and turn off the rest. Plug your RV cord into the inverter (You will need an inverter for 120 power off the battery). When on house power plug the RV cord in and turn on all the breakers.

Wow! Thanks to everyone for the quick reply. That does seem like a simple solution, and one I hadnt considered yet. I will give that more thought.

 

[AustinMilt]

I did my build this way. THe circuit breakers I shut off were Airconditoner 1, Air Conditioner 2, and Converter. This allows GFCI outlets and the other two non-GFCI outlets I have Along with an AC run ceiling fan.

It’s really as hard as finding a place to put your batteries and inverter and how to route it from the ceiling. I built my battery pack by the one that came from the trailer so I simply hooked 2 AWG cables to where the old battery went into the system. 4 Golf cart batteries, slide out tray, power boards with 3 SCCs, an Inverter, Busbars, and fuse box and fuses took up one side of my pass through compartment three or four feet deep.

Thanks for the additional details. That does seem well within my capabilities!

 

[Jasgeer]

I want to add solar to my travel trailer. I only care to power the things that the battery currently powers when off shore power (see attached) and the outlets. What I am unsure of is how to set everything up such that I can power those things off battery bank when not on shore power, but power everything on shore power when that's hooked up. I also want to be able to charge my battery bank when on shore power. I'm concerned about winding up with a loop that drains my bank, or worse.

I think what I need to do is put an inverter/charger between the battery bank and the GFI breaker. But I don't know what to do about the existing power converter /charger.

Any advice is greatly appreciated.

AustinMilt, you might want to check the charging voltage from your Parallax converter. I had a WFCO on my trailer and it really did a poor job of charging the deep cycle or AGM batteries. I bring this up as my batteries never charged over ~50%. I also wanted the batteries to charge while I was driving so I designed the attached system which incorporates a Renogy DC-DC charger.
I have an automatic transfer switch (just a relay) so that the inverter and shore power can never conflict. They are not expensive and idiot proof..
The output of the Parallax power supply could be disconnected from the fuses and run directly to the Renogy like I used and then connect the + of the 12V batteries to the place that feeds the 12V fuse distribution.

 

[GSXR1000]

option 1

 

[GSXR1000]

or any inverter with this

 

[AustinMilt]

Here is an alternative that powers everything except your converter.
Disable the converter as it would make a power loop with the inverter/charger.
Get an inverter/charger and connect the ac side and dc side as follows
eg = equipment ground

ac {
    pedestal->inlet->surge_protector->inverter_charger->master_breaker
}
dc {
    pos {
        |<->battery.pos
        |<->inverter_charger.pos
        |->dc_panel.pos
    }
    neg {
        |<->battery.neg
        |<->inverter_charger.neg
        |<-dc_panel.neg
        |<->inverter_charger.eg
        |<->chassis_bond
    }
}

I started out thinking I understood your diagram, but the more I look at it, the less confident I am that I understand it. I am going to try to spell it out, and please correct where I've got it wrong.

1. Connect the shore power inlet (through surge protector) into inverter/charger AC-in
2. Connect the master breaker to the inverter/charger AC-out
3. Connect battery positive to inverter/charger DC-positive (via busbar?)
4. Connect DC Distribution Panel battery/DC-positive (Part C in pictures) to inverter/charger DC-positive (via busbar?)
5. Connect battery-negative to inverter/charger DC-negative (via busbar?)
6. Connect DC Distribution Panel battery/DC-negative (Part D in pictures) to inverter/charger DC-negative (via busbar?)

There's some other stuff I just dont understand.

• I dont understand what to do with inverter_charger.eg or chassis_bond. What is chassis bond?
• Looking in my original pictures, what do I do with the CONV POS (converter positive). Just disconnect and wrap it up?
• Does this setup also use my battery bank to power the AC, CON(verter?), MIC(rowave), REF(ridgerator), and GFI outlets? If so, how could I change it so that the battery bank powers only the DC Panel stuff and the GFI outlets? Just wire up the inverter/charger AC-out to the GFI breaker? If I did that, looks like I wouldnt be able to power the other stuff on shore power.

Thanks so much for the time you took to write up a diagram, and apologies for my slowness.

 

[AustinMilt]

AustinMilt, you might want to check the charging voltage from your Parallax converter. I had a WFCO on my trailer and it really did a poor job of charging the deep cycle or AGM batteries. I bring this up as my batteries never charged over ~50%. I also wanted the batteries to charge while I was driving so I designed the attached system which incorporates a Renogy DC-DC charger.
I have an automatic transfer switch (just a relay) so that the inverter and shore power can never conflict. They are not expensive and idiot proof..
The output of the Parallax power supply could be disconnected from the fuses and run directly to the Renogy like I used and then connect the + of the 12V batteries to the place that feeds the 12V fuse distribution.

Thanks for the input. I have no reservations about cutting the existing converter out of the equation as long as I can make the system do what I like. I hadnt considered that the existing converter may be insufficient for charging my bank. I'll have to look into it. If I could hook it up through an inverter/charger, that seems like that would do everything. I just dont quite understand how to hook it up to power only some of my stuff (DC + outlets).

 

[AustinMilt]

or any inverter with this
View attachment 52388

Thanks for the reply! If you were going to use this, how would you hook up the ATS + inverter or inverter/charger so that it could power DC + outlets and charge the battery bank from shore power without creating a nasty loop?

 

[John Frum]

I started out thinking I understood your diagram, but the more I look at it, the less confident I am that I understand it. I am going to try to spell it out, and please correct where I've got it wrong.

1. Connect the shore power inlet (through surge protector) into inverter/charger AC-in
2. Connect the master breaker to the inverter/charger AC-out
3. Connect battery positive to inverter/charger DC-positive (via busbar?)
4. Connect DC Distribution Panel battery/DC-positive (Part C in pictures) to inverter/charger DC-positive (via busbar?)
5. Connect battery-negative to inverter/charger DC-negative (via busbar?)
6. Connect DC Distribution Panel battery/DC-negative (Part D in pictures) to inverter/charger DC-negative (via busbar?)

All of the above is correct.

There's some other stuff I just dont understand.

• I dont understand what to do with inverter_charger.eg or chassis_bond. What is chassis bond?

Inverter_charger.eg refers to the equipment grounding lug on the inverter that is usually labeled ground.

https://stevedmarineconsulting.com/wp-content/uploads/2014/08/070704DSCN0077.jpg

Don't worry, grounding confuses everyone.
Just connect the inverter_charger ground lug to the negative busbar and connect the negative busbar to the frame of the travel trailer.

This link should explain more about grounding.

Grounding Made simpler - Part 4: Mobile systems.

To get the paper, click on the orange button at the top of the screen. The subject of grounding is a complex, multifaceted subject, that is often treated as an after-thought but needs to be considered from the beginning of the design and build...

diysolarforum.com

My advice is not to get in the weeds with it for now.

• Looking in my original pictures, what do I do with the CONV POS (converter positive). Just disconnect and wrap it up?

The easiest thing to do is just switch off the converter ac breaker.
The better thing to do is to remove the hot wire from the converter breaker and make it safe with a wire nut.
Do the same with the converter neutral wire.
The converter dc positive and negative can optionally be disconnected from the dc distribution panel.
Finally you could just remove the whole converter module and have an extra breaker position in case you want to wire in an extra ac circuit.

• Does this setup also use my battery bank to power the AC, CON(verter?), MIC(rowave), REF(ridgerator), and GFI outlets?

Yes

• If so, how could I change it so that the battery bank powers only the DC Panel stuff and the GFI outlets?

Just turn off all the breakers for the ac circuits you don't want to use.
Say you want to power the GFCI outlet and the fridge, just leave the master breaker on plus the branch circuit breakers for the fridge and the GFCI outlet.

• Just wire up the inverter/charger AC-out to the GFI breaker? If I did that, looks like I wouldnt be able to power the other stuff on shore power.

Yes all the ac circuits

Thanks so much for the time you took to write up a diagram, and apologies for my slowness.

On the contrary I'm impressed with how quickly you grasp this tricky subject.

One thing I forgot to mention is that inverter_chargers have an integrated automatic transfer switch so switching back and forth from shore power to battery power is seamless.
You shouldn't even see the lights flicker.

 

[chrisski]

I don’t recommend doing away with the converter altogether. On those cloudy days when the batteries don’t charge enough, or at night when I leave a high wattage load that depletes my batteries too quick, I use the converter to charge the system.

I simply unplug my inverter from shore power, then hook my generator to the shore power, and flip the circuit breaker for the converter, and it will start charging the battery. The converter is not very strong And only provides 15 charging amps, compared to the 60 charging amps my solar panels can get, but with many cloudy days in a row, sometimes I need this.

 

[GSXR1000]

Thanks for the reply! If you were going to use this, how would you hook up the ATS + inverter or inverter/charger so that it could power DC + outlets and charge the battery bank from shore power without creating

just put the in line with the outlet circuit.... if the convertor is on that circuit move it (like to fridge breaker)

 

[chrisski]

I almost built my own automatic trans fare switch using this as a guide:

 

[time2roll]

The entire panel does not have to be powered up. Just use a small transfer switch on the circuit you want to have power.
The Xantrex transfer switch should work fine or consider the KISAE.
https://www.donrowe.com/KISAE-TS15A-Automatic-Transfer-Switch-p/ts15a.htm

I did this with a small 300 watt inverter. Placed the inverter behind the electric panel. Connect the 12v to the main battery feed and a short piece of Romex to connect to the transfer switch. No pulling wires, just make connections. Solar or existing converter charges the battery. Converter was moved to its own breaker.

A larger inverter gets to be a bigger issue as it should be close to the battery.

 

[AustinMilt]

The entire panel does not have to be powered up. Just use a small transfer switch on the circuit you want to have power.
The Xantrex transfer switch should work fine or consider the KISAE.
https://www.donrowe.com/KISAE-TS15A-Automatic-Transfer-Switch-p/ts15a.htm

I did this with a small 300 watt inverter. Placed the inverter behind the electric panel. Connect the 12v to the main battery feed and a short piece of Romex to connect to the transfer switch. No pulling wires, just make connections. Solar or existing converter charges the battery. Converter was moved to its own breaker.

A larger inverter gets to be a bigger issue as it should be close to the battery.

Thanks for your response. I drew a diagram of what I think you're suggesting. Can you take a look and tell me if that's right?

A couple additional questions

• How does the ATS stop power from coming from the batteries when I'm hooked to shore power. I thought the shore power needed to run through the ATS to cause it to switch. I suppose power might be coming back from the GFI line... is that it?
• Do the inverter AC-in or the converter negative (assuming that exists) need to connect to anything?

 

[AustinMilt]

just put the in line with the outlet circuit.... if the convertor is on that circuit move it (like to fridge breaker)

It sounds like you're suggesting the same thing as time2roll, right? That would make sense!

 

[GSXR1000]

It sounds like you're suggesting the same thing as time2roll, right? That would make sense!

yes but my link didn't require special plugs... and plus right into inverter...