Wire size from converter to battery issue

[Merlintiaga]

I have a 2022 Globetrotter. I am having an issue with my WFCO converter. It seems like it is not going into bulk mode regardless of the level of the lithium batteries (2 BB 100AH). The converter is a WFCO WF-9855-AD. The converter is in lithium mode. I called tech support at WFCO. They are thinking that the wire size from the converter to the battery may be too small given that the distance is 15' or so. Anyone else have this sort of issue? My lithium batteries can take over a day to charge on shore power. They only get 5 amps on shore power. I even tried disconnecting the solar b/c WFCO was thinking that maybe the solar was causing the issue. That didn't help. WFCO said that I may need new firmware installed in the converter (which requires shipping it back to them). I have a warranty appointment coming up so Colonial is going to deal with it, but I'd like to have an idea of where this is headed.

[Tyler2you]

I've got the same trailer and had the same WFCO Converter before I upgraded.

The ground wire that the factory installed on the DC side was pretty small (10 gauge) which I assume is because they're using the grounding block in the fuse panel which can't handle larger wire instead of running a wire over to the DC panel which can handle larger wires. The most I ever saw going into my AGMs was a bit over 16 amps.

When I did my Lithium upgrade, I switched to a PD converter. I used the WFCO to charge all of the Lithiums in the garage before taking them to the trailer and paralleling them. As an experiment, I tried charging with a 4 gauge wire on the positive side of the battery and an 8 gauge on the negative post. I would have tried 10 gauge, but didn't have a cable with a lug on it at the house. The best I saw going into the batteries with my clamp on meter was 18 amps. I swapped out the 8 gauge for 4 gauge and immediately saw 54 amps.

Not sure it was a purlely scientific test, but something to consider.

[s1000pre]

Your negative is completing the circuit, negative and positive always needs to be the same awg. A 10awg grounding wire should be fine, it isn’t carrying a load the same way as main feed wires.

[Tyler2you]

Originally Posted by s1000pre

Your negative is completing the circuit, negative and positive always needs to be the same awg. A 10awg grounding wire should be fine, it isn’t carrying a load the same way as main feed wires.

The factory install had 8 gauge from the positive DC output of the converter to one side of the disconnect solenoid and 10 gauge from the negative output to the ground lug inside the circuit panel.

[s1000pre]

Double check, I would be really surprised if it isn’t 6awg or 4awg. Airstream uses 8awg for the solar controller to roof panels. We’re talking a 55amp converter, 10awg won’t cut it.

[Merlintiaga]

Agree with s1000pre, these wire sizes look to me like they are very undersized. What's the point of putting in a 55A converter if the wire is creating so much resistance that less than 20A flows? Also, seems like upgrading the converter isn't going to help much with the small wires.

Tyler2you, did you install heavier wires when you upgraded your converter? And if yes, did you run them all the way from the fuse panel/converter to the batteries?

I'm pretty confused....seems like this is similar to trying chug a beer using a cocktail straw.

[Tyler2you]

Originally Posted by s1000pre

Double check, I would be really surprised if it isn’t 6awg or 4awg. Airstream uses 8awg for the solar controller to roof panels. We’re talking a 55amp converter, 10awg won’t cut it.

I'm 100% sure on the size of the negative wire. It was white 10 gauge to the circuit panel. The ground block in the panel won't accept anything larger. I'm pretty sure on the positive that it was 8 gauge, but could have been 6 at the biggest.

When I upgraded the converter, I used 4 gauge for both pos/neg and ran the negative back to the bus bar I installed next to the shunt.

[markuscis]

For another data point I got my 2022 27FB International this last July and have shipped my convert 9855-AD back for a firmware upgrade.

That said I went and checked the wires: red from converter to circuit panel is 6 AWG and white to circuit panel is 8 AWG, they routed the 8 AWG to the hole on the buss not the fuse panel side which is large enough for a 6 AWG wire in mine. They welded/soldered a 6 AWG white wire from that buss to the fuse buss at the top and then another white 6 AWG is from top of that same bus to the battery along with the red 6 AWG from the battery guard solenoid.

The white/red from the battery to the circuit panel are both 6 AWG.

[jeffb831]

All the wire sizes are provided in the owners manual. For the 2022 Globetrotter, they are on pages 80 (30A) and 81 (50A)

[Merlintiaga]

Great information! This will help me when I bring my GT to Colonial for warranty service.
:-)

[Tyler2you]

Originally Posted by jeffb831

All the wire sizes are provided in the owners manual. For the 2022 Globetrotter, they are on pages 80 (30A) and 81 (50A)

Maybe I don't know how to read a wiring diagram, but page 81 seems to have more connections than my WF-9855-AD has corresponding locations? There were only 3 wires attached to my converter. A red/positive cable (6 gauge), a white/negative cable (10 gauge), and a bare copper wire (12 gauge) attached to the chassis.

[jeffb831]

Originally Posted by Tyler2you

Maybe I don't know how to read a wiring diagram, but page 81 seems to have more connections than my WF-9855-AD has corresponding locations? There were only 3 wires attached to my converter. A red/positive cable (6 gauge), a white/negative cable (10 gauge), and a bare copper wire (12 gauge) attached to the chassis.

The other wires come out the opposite end of the unit in the form of a "plug". The end you are looking at is the "12V DC" output side of the converter. The other end (with the plug) is the "110V AC" input.

[Tyler2you]

Originally Posted by jeffb831

The other wires come out the opposite end of the unit in the form of a "plug". The end you are looking at is the "12V DC" output side of the converter. The other end (with the plug) is the "110V AC" input.

Yeah, that drawing confused me. I wondered about the 120 V side but it said it was the 12 V diagram.

What I really didn't understand was it showed two connections to the battery disconnect relay coming from the converter. Doesn't the relay only get 12 volts?

[Life is a Highway]

Talked to Vinnie at his place this summer it seems others have experienced this problem. They were in for service getting a Victron 3000 and lithium installed. I heard that WFCO converter dual profile charges slow with under 10 amps and takes forever. Our WFCO with the AGM batteries stock works perfect.

[CradHltn]

I'm having the same issue with my WFCO 9855 AD converter. I was told the battery was too far from my '16 bambi and I may need to change the wire size. Did Colonial fix your issue? If so did they change the wire sizes? Thanks in advance.

[lewster]

When we change the charging systems in Airstreams to solar and inverter/chargers, we always upgrade the cables leading into the house DC bank to a minimum of 4AWG on both sides; positive and negative. This gives you ample capacity to all of your DC needs.

I would suspect that a 10AWG negative cable would be your problem. I would upgrade both the positive and negative cables to at least 6AWG in your case. The negatives can be added into one of the 3 larger spaces in the negative bus bar that is present in your trailer. There is a smaller cable which might now be in one of those spaces that can be transferred into one of the smaller spots to make room for your new, large cable.

[99TJSE]

What's the best / most efficient way to pull cable from the converter area to the front under the queen bed on a Globetrotter 27 fbq?

[SuperTrouper]

Originally Posted by 99TJSE

What's the best / most efficient way to pull cable from the converter area to the front under the queen bed on a Globetrotter 27 fbq?

I followed Hugh's path through the floor past the water heater and in sealtite to the front.

https://www.airforums.com/forums/f44...ml#post1106431

After I completed mine working in Vinnie's shop back in the day, Vinnie figured out a way to pull down the banana wrap and run the chase through the outriggers for a cleaner appearance on all of his new solar installations.

[99TJSE]

Originally Posted by SuperTrouper

I followed Hugh's path through the floor past the water heater and in sealtite to the front.

https://www.airforums.com/forums/f44...ml#post1106431

After I completed mine working in Vinnie's shop back in the day, Vinnie figured out a way to pull down the banana wrap and run the chase through the outriggers for a cleaner appearance on all of his new solar installations.

Nice! Thanks...

[Merlintiaga]

Originally Posted by CradHltn

I'm having the same issue with my WFCO 9855 AD converter. I was told the battery was too far from my '16 bambi and I may need to change the wire size. Did Colonial fix your issue? If so did they change the wire sizes? Thanks in advance.

After the experience I’ve had and the fact that others have no issue with the Progressive Dynamics converter using the same size wires, I think we can conclude that it’s the WFCO converter. The problem is the the converter isn’t kicking into bulk mode. I don’t doubt that larger wires could help the WFCO sense that it needs to be in bulk mode, but IMO, this is squarely a WFCO problem. Still waiting for mine to come back from WFCO with the firmware update. This is a lot of time and effort going into a $250 converter. I am close to saying the heck with it and upgrading to the PD unit.