Solar panel check up on our 13QBB

[Sylvain]

Yes David, it's abominable.  Just remember that the solar panel was glued to the roof on four hockey pucks with construction glue!! 

The black wire really goes to the converter.  I forgot to mention that it started as a black wire at the solar charge controller and it ends up being red at the converter.  That's the red wire that you see at the back of the converter on the second photo.  The black wire probably wasn't long enough to go all the way to the converter so he connected a red wire to the black to make it longer.

I'm a electronic technician so I should be able to re-wire everything properly.  I was just curious about that wire going to the converter?  Is there any reason someone would need to have a connection between the solar charge controller and the rv converter?

There is no fuse at the battery.  I believe the 15A breaker at the solar charge controller output is doing that job.  The wire from the panel to the controller and from the controller to the battery is 10awg.  The distance between the controller and the battery is only a few feet.

Thanks......Sylvain

[DavidM]

OK, good you have the skills to do this right. Here is what I would do:

Remove the black wire wrapped around the red one and pull it back to the converter, and disconnect it. Tape up the insulation cut. I see no reason for a separate wire to the converter. The converter was already wired to the battery, right?

My 2013 16TBS had no fuse between the battery and the converter. That is very poor practice but lots of RV builders do it. The wire to the converter on mine goes about ten feet underneath the trailer. It is exposed and if a rock hit it, dinged the insulation and shorted to the frame it could possibly burn up.

So I installed a water proof 30A breaker within a foot or so of the battery on the positive wire. It also serves as a disconnect. This is what I used: https://www.amazon.com/gp/product/B00DIGK346/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1. I used the defunct break away battery box (I wired the breakaway switch directly to the house battery) and it makes a good place to bring all of the wires together.

Then wire your converter, and the solar controller's output to the downstream side of that breaker. Then you will have a safer system.

David

[Sylvain]

Ok, thanks a lot again for all the information David.  Yes my converter is connected (from the factory) to the battery.  I don't think there is a fuse between my battery and the converter on my trailer too.  I may install something similar to you.  Do you have a photo of that set up in your battery box?  That would be great!

Thanks a lot........Sylvain

[Merlin]

I for sure agree with DavidM. Yikes. I wonder what other dangerous connections were made in that installation? In addition to the bad connection, that mysterious black wire is not protected by the circuit breaker, but nothing else may be protected by those breakers either. I don't know how DC circuit breakers work, but those are wired backwards according to the installation instructions for Midnight Solar breakers. I looked up the installation instructions for that controller too, just to check on in/out connections. If you could definitively find out what the black wire is connected to, we might be able to help some. For example, if it goes to the converter, which terminal?  I sure can't think of a purpose for that. All things considered, take DavidM's advice and get pro help. You don't want to do any accidental welding or start any fires with the high current from the battery (says the voice of experience).

[Sylvain]

Thanks for your reply Merlin.  Thanks for pointing out the fact that the breakers are connected the wrong way.  I'll have a look at them.  I checked the rest of the wiring it it looks fine.  It's a very simple system and there is not much wiring.  As soon as time allows I would like to open the back of the converter and see where that wire is connected.  I'll let you know.  I already disconnect that weird wire.  Everything seems to work fine eventhough it's disconnected.  I sent a message to the previous owner about that wire but he didn't replied.

Thanks..........Sylvain

[Merlin]

I did the same thing as DavidM and installed a breaker in my battery box. This one also serves as a convenient on/off switch. They come in different amperage ratings.

https://www.solar-electric.com/mrcb-30-amp-dc-circuit-breaker.html

[Sylvain]

Ok thanks.  I'll do the same thing.  I couldn't find the same breakers on Amazon Canada that you and David suggested.  I found this one though.  Would it work?

T Tocas 30 Amp Surface-Mount Circuit Breakers with Manual Reset for Auto Boat Marine, 12V- 48V DC, Waterproof https://www.amazon.ca/dp/B07D7T3ZR5/ref=cm_sw_r_cp_tai_l6YXCbSA06D2V

Thanks......Sylvain

[Sylvain]

Is this the proper way to cennect it?  I would install the circuit breaker less than 12" from the battery.

[DavidM]

Your breaker looks fine, and cheaper too!! Your installation diagram is good too.

David

[Bluewaterbound]

You say full sun but most likely is not given the morning sun. You also need to understand the load on the system to get a good panel output reading. Google "effects of shading on solar panels" etc.. Partial shading of even one cell may reduce its power output. Because all cells are connected in a series string, the weakest cell will bring the others down to its reduced power level. Much depends on how the panel was manufactured but lower cost panels will see the type of drop you are seeing. Also lower sun angle will greatly reduce the output. Solar cells also degrade over time. The panel rating is with direct overhead full sunlight no shade. I have 6 of the sun power cell flexible 100W panels mounted to the roof of my Campsite 21RBS. When I first installed my system I would see ~30Amps in full overhead sun. After a storm of with  3/4" hail stones I see a 20% degradation in my system. I can see some small dents in the panels plastic. I would not recommend these flexible panels. They are expensive per watt and IMO do not hold up. Doing some searches on Amazon I see many framed, more cost effective panels that will hold up to hail etc.

[Sylvain]

Your breaker looks fine, and cheaper too!! Your installation diagram is good too.

David

Great, thanks David!

You say full sun but most likely is not given the morning sun. You also need to understand the load on the system to get a good panel output reading. Google "effects of shading on solar panels" etc.. Partial shading of even one cell may reduce its power output. Because all cells are connected in a series string, the weakest cell will bring the others down to its reduced power level. Much depends on how the panel was manufactured but lower cost panels will see the type of drop you are seeing. Also lower sun angle will greatly reduce the output. Solar cells also degrade over time. The panel rating is with direct overhead full sunlight no shade. I have 6 of the sun power cell flexible 100W panels mounted to the roof of my Campsite 21RBS. When I first installed my system I would see ~30Amps in full overhead sun. After a storm of with  3/4" hail stones I see a 20% degradation in my system. I can see some small dents in the panels plastic. I would not recommend these flexible panels. They are expensive per watt and IMO do not hold up. Doing some searches on Amazon I see many framed, more cost effective panels that will hold up to hail etc.

Thanks for the added information. 

[Sylvain]

I finally found where that fishy cable was connected in the RV converter.  It was connected to the battery terminal inside the converter (photo).  I really can't understand why he would have connected that wire there??

Sylvain

[DavidM]

No reason, it was just a redundant parallel connection to the battery The real problem was that screwy splice. If it had come loose and there was no fuse/breaker at the battery, it could have touched ground and at best burnt the cable, at worst burned up your camper.

David

[Sylvain]

And I found another screwy splice really close to the converter on another wire.  I did use heat shrink to protect those splices.  Everything is fine now!