24V System Wire Sizing help

[JonBartee7]

So it looks like I might have been wrong about what wires have been routed from the breaker box to the hitch. I got under there and it appears that 6 or 8 awg wire is routed from the dc distribution and it looks like there is a 10awg triplex wire that could be coming from the ac distribution panel.

I also attached some pictures of where the hole for wires is in the passthrough storage and where they are going to.

 

[John Frum]

So it looks like I might have been wrong about what wires have been routed from the breaker box to the hitch. I got under there and it appears that 6 or 8 awg wire is routed from the dc distribution and it looks like there is a 10awg triplex wire that could be coming from the ac distribution panel.

I also attached some pictures of where the hole for wires is in the passthrough storage and where they are going to.

What am I supposed to see in the pictures?
What were you wrong about?

 

[John Frum]

This is the product link for the solar charge controller.

Wall Mount MPPT Solar Charge Controller

Furrion's 25-Amp and 50-Amp solar controller with MPPT technology optimizes your solar panel output to provide the maximum amperage to your RV batteries.

furrion.com

 

[JonBartee7]

What am I supposed to see in the pictures?
What were you wrong about?

Well I was hoping you might be able to help me make sense of everything going on with the existing wiring and where I could hook everything into on the DC side. I understand if it's not enough to just see the pictures of everything.

What I was wrong about is I thought 10awg wire was being run from the current FLA battery to the dc distribution panel but I believe its 6awg. In a previous reply, you mentioned that I could use 6awg wire to run from lynx distributor to the 24to12v converter if I put the converter right next to the ac/dc distribution panel instead of in the passthrough storage. So I was hoping that meant that I could use the existing wires for the converter which would simplify a lot for me.

I contacted the tongue jack company and I am waiting for a more concrete response from them if I can use the converter to power it or not and get the specs for the rated draw and locked rotor amps. It looks like there's not gonna be a good way to power it and the breakaway cable through a 24v system though, so I was wondering what you might suggest for that? I can get another 12v battery to power them but now I don't have anything to charge that battery with since I removed the old solar panel and scc.

 

[John Frum]

Before I map the wiring in those pictures, have you considered putting your system under the dinette seats?
Just about everyone ends up putting there system under the dinette or bed depending on the trailer configuration.

 

[JonBartee7]

Before I map the wiring in those pictures, have you considered putting your system under the dinette seats?
Just about everyone ends up putting there system under the dinette or bed depending on the trailer configuration.

Well I gutted the dinette when I got the rv and put a desk in there. also the heater and water pump were under each of the booth seats and those have been recovered. Under bed storage is packed full and a foot away from the passthrough storage so I don't see how that would change much.

Could I use the victron orion charger and connect it to lynx distributor and FLA battery to charge it?

https://www.amazon.com/dp/B085G72RQ2?ref_=cm_sw_r_cp_ud_dp_1XPK86PHPWS8R1PMXJ6P

That way I can leave the dc wiring alone and just use the orion to charge the house battery

 

[John Frum]

Well I gutted the dinette when I got the rv and put a desk in there. also the heater and water pump were under each of the booth seats and those have been recovered. Under bed storage is packed full and a foot away from the passthrough storage so I don't see how that would change much.

Could I use the victron orion charger and connect it to lynx distributor and FLA battery to charge it?

Yes.
The non-isolated version(if there is one will be cheaper).
You want the 12 volt run short and the 24 volt run long.

https://www.amazon.com/dp/B085G72RQ2?ref_=cm_sw_r_cp_ud_dp_1XPK86PHPWS8R1PMXJ6P

That way I can leave the dc wiring alone and just use the orion to charge the house battery

I think you mean the breakaway battery, confirm?
The house battery is 24 volts.

 

[John Frum]

How are you going to power the dc distribution center?

 

[John Frum]

For reference this is the pinout and colour codes for the tow cable.

https://www.etrailer.com/question-252629.html

 

[JonBartee7]

Yes.
The non-isolated version(if there is one will be cheaper).
You want the 12 volt run short and the 24 volt run long.

ok cool, I don't see a non-isolated version on amazon but at this point I'm willing to bite the cost if it will simplify things. What's the difference between the isolated and non-isolated?

I think you mean the breakaway battery, confirm?
The house battery is 24 volts.

sorry ya typed that in a hurry. Meant the 12v FLA battery to replace the dying one that came with the RV. the one that will power the tongue jack and breakaway cable.

How are you going to power the dc distribution center?

I figure if the orion charger can keep the 12v battery topped off through the day, I can just leave the DC system alone as is and just run the orion to the battery in place of where the wires from the legacy scc was charging them. Would I leave the ac2dc converter in there at that point?

 

[John Frum]

ok cool, I don't see a non-isolated version on amazon but at this point I'm willing to bite the cost if it will simplify things. What's the difference between the isolated and non-isolated?

The isolated dc2dc step down charger has a negative in and a negative out.
They are usually more expensive and less efficient.
I only use them for to avoid issues with parallel return paths and ground loops in specific situations.

The non-isolated dc2dc step down charger has a common negative.
Should be fine for your setup.

I figure if the orion charger can keep the 12v battery topped off through the day, I can just leave the DC system alone as is and just run the orion to the battery in place of where the wires from the legacy scc was charging them.

You mean the 12 volt battery?
I don't know how the legacy scc is wired.
I don't think we have discussed how you plan to integrate the legacy SCC.

Would I leave the ac2dc converter in there at that point?

Powering the ac2dc converter from the inverter is brutally inefficient.
If that is ok with you it makes the wiring much easier.

 

[John Frum]

I propose for a test that you disconnect the tongue battery and see if the ac2dc converter can power the jack.

If it can then I think the dc2dc charger is not required.

The tongue battery will be charged by the 7-pin cable when you are towing and by the ac2dc converter when you are on shore power.
The legacy SCC could also be charging the tongue battery.
We need to talk your solar strategy.

 

[John Frum]

I can see that I've not been clear.
Since you will have a tongue battery the jack should work fine.
Since the legacy battery is being charged by the ac2dc converter, tow cable charge line and possibly the legacy scc I don't see any issue at all.
The dc distribution panel will be energized by the ac2dc converter which is inefficient but otherwise fine.

 

[JonBartee7]

You mean the 12 volt battery?
I don't know how the legacy scc is wired.
I don't think we have discussed how you plan to integrate the legacy SCC.

legacy system is as so: solar panel -> SCC -> 12v FLA battery
I have removed the old solar panel and will be removing the old SCC as well.
My plan now with the orion is: lynx distributor -> orion -> 12v fla battery

Powering the ac2dc converter from the inverter is brutally inefficient.
If that is ok with you it makes the wiring much easier.

Well I would like to have power to the dc distribution when plugged into shore power still. Is there a way to allow the ac2dc converter to work when plugged into shore power and disabled when inverting?

I propose for a test that you disconnect the tongue battery and see if the ac2dc converter can power the jack.

If it can then I think the dc2dc charger is not required.

The tongue battery will be charged by the 7-pin cable when you are towing and by the ac2dc converter when you are on shore power.
The legacy SCC could also be charging the tongue battery.

ok ya but I have decided that if I cannot use a 24v to 12v dc2dc converter to power all my dc appliances then I am just going to get another 12v battery dedicated for the DC side of the system. I need to have dc power 24/7 because my fridge is run on 12v dc only. Cannot be powered any other way. And I live out of my rv so I always need the fridge on. like in the scenario that I run out of power from the 24v battery bank, I would like to have the 12v battery bank still available.
I have had the DC side run off of this existing battery for almost a year now without issue so I figure why change that if it is going to become a hassle to wire into the new system.
The only caveat being that I am not charging that 12v FLA battery with the solar/scc anymore so the orion seems to be my best bet for keeping it charged.

We need to talk your solar strategy.

4* 250 W panels in series parallel connected to a victron smartsolar 100|50 scc connected to the lynx distributor.

Since the legacy battery is being charged by the ac2dc converter, tow cable charge line and possibly the legacy scc I don't see any issue at all.
The dc distribution panel will be energized by the ac2dc converter which is inefficient but otherwise fine.

The legacy battery is charged by the solar panel and scc. the battery powers the DC distribution panel unless connected to shore power, in which case the ac2dc converter powers the dc distribution panel and charges the battery. That is the legacy setup.

What I am trying to figure out is that I am removing the old solar panel and scc and the new solar array and scc will only be used to power the 24v battery bank at the moment. Can I use the orion-tr smart 24/12v dc2dc charger to charge the 12v fla battery through the 24v battery bank instead of the legacy solar panel and scc?

 

[John Frum]

@JonBartee7 are you not hearing me saying that you don't need the orion?
The 12 volt battery is currently being charged by the 7 pin cable and by the ac2dc converter.
Please acknowledge that you hear me.

 

[John Frum]

I need to have dc power 24/7 because my fridge is run on 12v dc only.

Please post a product link to your fridge.

 

[JonBartee7]

are you not hearing me saying that you don't need the orion?
The 12 volt battery is currently being charged by the 7 pin cable and by the ac2dc converter.
Please acknowledge that you hear me.

I hear you. You also said that charging through the ac2dc converter is highly inefficient. Would it not be more efficient to use the orion to charge the 12v battery? and then only have the ac2dc converter on when plugged into shore power? I could just switch the breaker for it off when not on shore power. I don't plan to have shore power very often after installing all this.

 

[John Frum]

I hear you. You also said that charging through the ac2dc converter is highly inefficient.

It is.

Would it not be more efficient to use the orion to charge the 12v battery?

Yes.

and then only have the ac2dc converter on when plugged into shore power?

You don't need both.

I could just switch the breaker for it off when not on shore power. I don't plan to have shore power very often after installing all this.

See my next message.

 

[John Frum]

If you choose the orion I would put it as close to the dc distribution panel as possible, disable or remove the ac2dc converter and make sure the wire up to the tongue is properly sized.
The battery can handle the surge current and the charger can handle the rest.
You don't need a lot of current flow to charge the battery.

 

[John Frum]

If the orion will fit I suggest you put it where the ac2dc converter currently resides.