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rportillo · 08-03-2019, 05:23 PM

Hi
I’m trying to identity what the distribution bar is under the cover of my DC Panel, on the 2018 26’ RB Flying Cloud. The DC PANEL I’m referring to sits unrest the front lounge table, driver side. See picture attached. I have identified a negative buss bar, silver, clearly connected to ground cables. Also a positive bus bar, clearly connected to the positive side of the battery and conveter. But what is the third bar in the lower right side, grey color with small screws. It is being used for both positive and negative wires. Is this a small fuse panel or just a place to connect wires in a central location?

rportillo · 08-03-2019, 05:31 PM

Correction. My images got rotated. The wire are feeding in from the floor of the coach (left side of image). The bar I’m trying to identify is closest to the floor. It looks like a DC fuse bar, but is not being used for that purpose? Is airstream using it to connect wires that were routed from other places on the trailer, to shorter segments that connect to the positive and negative bars?

uncle_bob · 08-03-2019, 06:54 PM

Hi

In your picture you have four things:

1) A DC bus feeding a set of thermal (self resetting) breakers.

2) A connection strip that mates what is inside the box to the main wiring harness

3) A ground bus bar

4) What looks like an additional thermal reset breaker sitting all by it's self

It appears that the bus bar and "extra" breaker are further from the floor than the connection strip and the ground bus. It is a bit tough to tell just which side is the floor.

Bob

rportillo · 08-03-2019, 09:20 PM

Hi Bob
The ground bus bar and “connection strip are closest to the floor.
The DC bus and “thermal breaker” are mounted higher above the floor.

I’m going to move some lithium batteries inside and will be doing some re-wiring. I’m trying to get my head around all the connections. I do have the wiring diagrams from airstream. But I did not see the grey connection strip on the diagrams. Is that just a central place to connect wires from the trailer to either the DC bar or Ground bar. And these connections are not fused, in this strip

The thermal reset breaker you mentioned might actually be a 1 amp LP detector fuse, according to the schematics.(M-11) in the attached diagram.

rportillo · 08-03-2019, 09:24 PM

Trying to attach picture of schematic.

uncle_bob · 08-04-2019, 07:00 AM

Hi

All the "added thing" does is give them a place to tie the (pre assembled) stuff in the gray box to the wiring harness in the trailer. I suspect it's a running change made after the schematic came out.

Yes, that's just a guess based on the pictures. Without a close inspection there is no way to be 100% sure.

Bob

guskmg · 08-04-2019, 04:58 PM

The heavy red wires are battery leads that feed the bus and all the others are the ones being fed. You probably knew that, but I did not, until lewster pointed that out to me. There are probably two other 50amp breakers within 18"of each battery positive terminal. The two heavy red wires are probably 6ga. We replaced them with wire coming from the 3,000w inverter/charger to power the trailer. The other connections will be from the inverter, a short much heavier duty cable that only runs a few feet to the battery bank. You will also need a much heavier lead and as short as possible from the solar collector box to the batteries. If you have ny questions, Call (lewster) Lew Ferber at: 541-490-6357. He is always helpful.
guskmg

the battery to inverter's

rportillo · 08-05-2019, 08:34 AM

This makes sense. Except, in my case, one of the red 6 ga. connects directly to the battery (not fused ), with car type battery post connections at the battery. The other red cable disappears into the subfloor with a ground cable and some other DC cables. I assume this is going directly to automatic shore power relay, (see schematic), located behind the power panel under the frig. I was expecting that relay to be here in this front DC panel, like my older trailer. I have not opened up that main power panel other than to turn off some AC breakers.

I have red and black, 4 gauge, welding wire connected directly from batteries to the 1000w pre-installed WFCO inverter. These are not in the picture above. The red 4ga. has a 100A fuse close to the battery terminal side. When I move the batteries inside, this cable will get much shorter. But I’m surprised how long this inverter cable runs as installed. The cables must be 8 feet long. I just looked up a wire chart that said 4ga. is good for 100A up to 100 feet, so I guess it’s ok.

Thanks for the input.
-Ralph

uncle_bob · 08-05-2019, 08:40 AM

Quote:

Originally Posted by rportillo

This makes sense. Except, in my case, one of the red 6 ga. connects directly to the battery (not fused ), with car type battery post connections at the battery. The other red cable disappears into the subfloor with a ground cable and some other DC cables. I assume this is going directly to automatic shore power relay, (see schematic), located behind the power panel under the frig. I was expecting that relay to be here in this front DC panel, like my older trailer. I have not opened up that main power panel other than to turn off some AC breakers.

I have red and black, 4 gauge, welding wire connected directly from batteries to the 1000w pre-installed WFCO inverter. These are not in the picture above. The red 4ga. has a 100A fuse close to the battery terminal side. When I move the batteries inside, this cable will get much shorter. But I’m surprised how long this inverter cable runs as installed. The cables must be 8 feet long. I just looked up a wire chart that said 4ga. is good for 100A up to 100 feet, so I guess it’s ok.

Thanks for the input.
-Ralph

Hi

Except for the "extra" connector, the wiring diagram in your owner's manual should be accurate. AS does not put fuses / breakers at the battery posts. The thermal breaker that is attached to the bus bar (and is shown in your picture along with a number of others) serves to isolate the battery.

Bob

rportillo · 08-05-2019, 10:41 AM

A correction to my previous post about 100' for 4ga at 100A:
According to this chart from a previous Airforum post:
http://assets.bluesea.com/files/reso...on_chartlg.jpg

So 4ga wire is good for 10' with 3% voltage drop and 30' for 10% voltage drop. This seems more reasonable. And my current setup is just under 10'.

-Ralph

AKNate · 08-05-2019, 11:26 AM

It looks like yours is wired the same as mine. If you’ll notice in the drawing, there is a note saying the copper post on the circuit breakers is the line side and should be facing out for CB-1. Whoever built these panels just made them all symmetrical and ignored what the drawing said to do. I reversed mine to match the drawing.
The gray “bar” is just a bunch of DIN rail mounted terminal blocks. Normally those are where you land external wiring to a prebuilt panel, but rather than doing that Airstream bizarrely has pigtails hanging off the terminal blocks that they butt-splice to the wiring harness when they install it, thereby defeating the whole point of the terminals. I cut off all the splices and extra several feet of wire on mine and landed all the wires directly on their terminals.

rportillo · 08-05-2019, 02:41 PM

Hi
Yea I see pigtails and butt slices also coming into the DIN rail. I’ll try to clean up the same. I think airstream requires leaving extra wire for re-work, maybe that’s why they did this?

Regarding the positive bus bar. I can see the wiring is different than the diagram, but still not clear that what the diagram “says” and what is “drawn” is the same. The schematic says “all copper studs connect to copper bus bar, except CB1”. What does that mean? CB1 for me is the 6ga. battery cable connected to the first terminal.

It seems to me CB1 is drawn correct in the diagram and connected correct in my DC Panel. But CB2 should be connected to the 2nd terminal and directly on the copper strip. And it is not in the DC Panel. Additionally, the remaining connections 3, 4, 5 and 6, do not match.

AKNate · 08-06-2019, 11:16 AM

Correct - CB1 is the 6 awg from the battery. Each circuit breaker has two studs (threaded posts) - one is copper colored and one is silver colored. The copper stud is supposed to be connected to the battery source side and the silver stud to the load side. All the breakers except CB1 feed out from the copper bus bar to various loads. CB1 however feeds into the busbar from the battery, hence the note. That breaker was supposed to be installed oriented the opposite way, with the copper stud facing down and the silver stud connected to the copper bus bar.
I think Airstream does the pigtails and butt-splices to speed manufacturing. They have spare length in the wire harnesses so they don’t have to worry about being precise when they run them or coming up short. They run the cables, go crimp, crimp, and they’re done. It’s a fast, but IMO shoddy way of doing wiring.