Wanting to increase solar

[billrector]

Originally Posted by Dorsalis

We also purchased a 2017 FC 23FB with which we have been mostly very happy. However, like you, we requested the solar upgrade, which consisted of an 80 Watt Zamp roof panel, which is connected to a 3 receptacle receiver box on the roof. We came across an offer on the internet for an "Airstream Solar Upgrade", which offered 2 additional 80 Watt Amp panels with plug ins designed especially for the 3 receptacle receiver box. SO, I purchased the two additional panels and installed them. Before doing this I called Airstream Technical Support and specifically asked if the Solar system (solar controller wiring etc...) could handle the extra two panels. I was ABSOLUTELY ASSURED that the circuit could handle the additional 2 panel option. I was told that the reason for the three receptacle box was specifically to allow for this option, to upgrade with another 2 80 Watt panels. However, after installing the system, a fuse under the bed mattress started blowing out whenever we had a strong sunlight. I called technical support several times about this, particularly as the trailer was still under warranty. Finally, I spoke with a technician who informed me that "...well, we don't offer a 3 panel upgrade on the 23FB as yet because we have not worked out all the bugs...". I sincerely wish they had advised me of this BEFORE I purchased and installed the additional two panels. As things stand now, I must keep two of the panels unplugged and just use one, which barely keeps up with a "Trickle Charge" for the system.

Our conclusion in all this was that Airstream is presently naive and untried in Solar Panel systems. The solar controller and wiring system they have put in on the 23FB models is entirely inadequate for anything more than an 80 Wall system. We also made the mistake of purchasing a Zamp portable solar panel system ( we were really thinking we could amp up our solar). That one also is a problem when used in combination with the existing 80 Watt panel. Once again, when we purchased the portable panel, we were ABSOLUTELY ASSURED that the Airstream was rigged to handle the extra loads. Clearly, the 23 FB is not.

Overall, we are delighted with the 23 FB in its design and function. We love the way it pulls, the small footprint for getting in to parking spaces, the overall ergonomics of the Trailer. If it were not for this Solar Panel defect, the trailer would (at least for us) be PERFECT.

Can you tell us what fuse size keeps blowing? Your panels should put out less than 5 amps. A parallel arrangement should then provide 15 amps to the controller. 15 amps should easily be handled by the 10 gauge wire that Airstream runs from the roof to the controller. As long as your controller can handle 15 amps, I don't see a problem. Could your fuse be undersized? If so, simple fix.

[Bobbo]

Originally Posted by billrector

Can you tell us what fuse size keeps blowing? Your panels should put out less than 5 amps. A parallel arrangement should then provide 15 amps to the controller. 15 amps should easily be handled by the 10 gauge wire that Airstream runs from the roof to the controller. As long as your controller can handle 15 amps, I don't see a problem. Could your fuse be undersized? If so, simple fix.

I'm not the guy who posted about the fuse blowing, I am the OP who started this thread. I can't answer as to what his fuse really is, but the schematics show a 10 amp fuse.

To me, this is very promising. I can add two more 80 watt panels in parallel, upgrade that 10 amp fuse under the bed to 20 amp, and be golden.

He also said he had some problems using a portable panel in conjunction with his single roof panel, but he doesn't say what that problem is. I really can't see what that problem could be because the portable panel will have its own controller, and hook directly to the batteries. It should be no different than having a 120v charger hooked up in addition to his solar. They should not interact at all.

[TouringDan]

Originally Posted by Wolfwhistle

I made a simple / functional drawing of what series / parallel entails and hope it clears that up for anyone interested. I didn't know where to stop and added a (-) bus and shunt. This is the specs for Renogy Eclipse* 100 Watt 12 Volt Monocrystalline Solar Panel... Sold by: Amazon.com Services, Inc. I have no dog in the fight what product or where you get it, but I like Renogy so far.

I mentioned in the other reply about drilling thru the ceiling after fishing to center between wardrobes. Another member mentioned drilling up thru the wardrobe. Doing it over I would drill thru inside that wardrobe. Away from ribs / supports / wires.
Clint / WW

WW

Thanks for posting the functional diagram. I am using a Victron 100v/15a controller. It already has a 20 amp fuse in it. Is it also necessary to install a circuit breaker in the line since it is already protected by a 20 amp fuse?

Thanks, Dan

[daleyocum]

Originally Posted by Bobbo

I'm not the guy who posted about the fuse blowing, I am the OP who started this thread. I can't answer as to what his fuse really is, but the schematics show a 10 amp fuse.

To me, this is very promising. I can add two more 80 watt panels in parallel, upgrade that 10 amp fuse under the bed to 20 amp, and be golden.

He also said he had some problems using a portable panel in conjunction with his single roof panel, but he doesn't say what that problem is. I really can't see what that problem could be because the portable panel will have its own controller, and hook directly to the batteries. It should be no different than having a 120v charger hooked up in addition to his solar. They should not interact at all.

I agree, the fuse has no reason real reason to be that small with 10 ga wire. You could go to 30amps easily as far as the wire is concerned. They were probably just being conservative with that small fuse.

I don't know what solar controller Airstream uses but my Victron wants to keep a close eye on battery voltage (with lead-acid) so as not to overcharge. I'm not sure what it will think about the external panel pumping in power as well. It might decide the battery is charged when it's not. A far batter way to handle an external panel would be to remove its cheap built-in controller and wire it's (18v or so) output directly in parallel with the rest of your solar array on the roof. If your external panel doesn't have diodes to block current trying to flow back into the panel you may need to add one. I'd call the manufacturer on that one. With the direct connection the trailer's controller will know what's going on and float when the battery is charged but not before.

I suspect you'll want to upgrade the stock AS controller at some point if it's not rated to handle all the current you'll now have available. It won't blow up or anything, it just may not be able to fully use all your new-found energy.

By the way, in parallel there's no need for all the roof panels to be the same size. You may be able to throw up some 100w ones for the same price.

[uncle_bob]

Originally Posted by daleyocum

I agree, the fuse has no reason real reason to be that small with 10 ga wire. You could go to 30amps easily as far as the wire is concerned. They were probably just being conservative with that small fuse.

I don't know what solar controller Airstream uses but my Victron wants to keep a close eye on battery voltage (with lead-acid) so as not to overcharge. I'm not sure what it will think about the external panel pumping in power as well. It might decide the battery is charged when it's not. A far batter way to handle an external panel would be to remove its cheap built-in controller and wire it's (18v or so) output directly in parallel with the rest of your solar array on the roof. If your external panel doesn't have diodes to block current trying to flow back into the panel you may need to add one. I'd call the manufacturer on that one. With the direct connection the trailer's controller will know what's going on and float when the battery is charged but not before.

I suspect you'll want to upgrade the stock AS controller at some point if it's not rated to handle all the current you'll now have available. It won't blow up or anything, it just may not be able to fully use all your new-found energy.

By the way, in parallel there's no need for all the roof panels to be the same size. You may be able to throw up some 100w ones for the same price.

Hi

Ok you complain that you did an upgrade on your system and forgot to switch out a fuse. Somehow that is an AS issue rather than your oversight. I really can't see how that is the case. The fuse was properly sized for protection of the stock setup. ( = it can only blow the fuse if there is a major problem). If you get into DIY, you need to understand what you are doing.

If you spend a bit of time looking into it rather than just guessing, the stock AS controller isn't all that bad. It certainly does not have a lot of bells and whistles, but it does a good job. If you want BlueTooth monitoring, that's not what it does.

If you run panels in parallel they do indeed need to be matched up. There are a number of different output curves possible and if they don't match ... you loose.

Lots of fun ...

Bob

[daleyocum]

Originally Posted by uncle_bob

If you run panels in parallel they do indeed need to be matched up. There are a number of different output curves possible and if they don't match ... you loose.

Lots of fun ...

Bob

I think perhaps Bob was thinking of the series/parallel arrangement. The parallel panels are all producing varying amounts of power anyway (with shading, etc.) so I’d feel fine about mixing 80w and 100w panels.

[uncle_bob]

Originally Posted by daleyocum

I think perhaps Bob was thinking of the series/parallel arrangement. The parallel panels are all producing varying amounts of power anyway (with shading, etc.) so I’d feel fine about mixing 80w and 100w panels.

Hi

Nope, panels are made up of some number of basic PV cells. There is no "standard" number of cells for a 12, 24, (or whatever) volt array. If one panel manufacturer decides on 36 cells and the other goes for 34 or 32 cells, they will not do well when put in parallel. The may well do just fine run in series ... (or they may not).

How big a deal is all this? It's a lot bigger deal than our perpetual arguments about a 2 or 3% loss in a piece of wire.

Bob

[daleyocum]

Originally Posted by uncle_bob

Hi

Nope, panels are made up of some number of basic PV cells. There is no "standard" number of cells for a 12, 24, (or whatever) volt array. If one panel manufacturer decides on 36 cells and the other goes for 34 or 32 cells, they will not do well when put in parallel. The may well do just fine run in series ... (or they may not).

How big a deal is all this? It's a lot bigger deal than our perpetual arguments about a 2 or 3% loss in a piece of wire.

Bob

This got me thinking about a lot of pretty technical things. Rather than hijacking this thread I started a new one. It got me thinking about blocking diodes and the tradeoffs in using them even for cases where all the panels are matched. Also, that is a place to educate me as to why putting a 100w panel in parallel with an 80w panel is any different than having two matched 100w panels but one is 20% shaded.