Solar Install (Part 3)

As we left our story I had just got the cables (battery, monitor, and temperature) ran to the back of the refrigerator through the underside of the dinette bench.  I showed Roxie the progress and she asked if I was going to put the controller under the dinette.

I said that I was going to put the controller behind the refrigerator and had already put a lock on the refrigerator door:

However, she had a really good idea.  By putting the controller, switch, and breaker under the dinette it was much more secure and more accessible.  All I had to put in the refrigerator area was the 2 gauge wires going to the top of the trailer through the refrigerator vent.  That proved to be a bit problematic.

In our ’92 the area behind the refrigerator was wide open.  Lots of room.  However, in the 2012 it appears that Airstream created more of a controlled updraft for more efficiency.  In looking at the specifications for the refrigerator they do have plans for a tight air draft configuration.  But this makes it harder, nearly impossible, to drop a cable behind the refrigerator.  But another problem was that I had the cable at the BOTTOM of the refrigerator!

I have to take the refrigerator out.  I have done it before in our other trailer and knew there weren’t too many screws, etc. holding it in.  It is just a larger one than our other one and much more cumbersome.  As luck would have it our son came by right when I was going to take it out. He was able to muscle it out and I had all day to work on it.  Alas, I did not take pictures.

Another issue was the gauge of wire.  At the top of the trailer, the combiner box attaches to the refrigerator vent but I could not bend the 2 gauge wire enough to get the combiner box cover on.  I had to use a smaller gauge for the combiner box, I chose 6 gauge.  It would still handle the current.

I followed her recommendation and mounted it all under the dinette:

Above you can see the solar panel cutoff switch, the solar panel controller, and the circuit breaker.

Also, the wiring behind the refrigerator is much simpler:

The next step was doing the panels on the roof but first I wanted to get some of the internal wiring cleaned up.  The set of three wires that go from under the dinette to under the couch goes along the base of the wall and needed some wire management:

There is also a set of two wires that go to the IPNPro Remote that I mounted on the wall:

Now off the panels on the roof.  I have 3 Grape Solar GS-160 panels to mount.  I had an idea where to put each of them but still had a bit of trepidation of the actual fitment.  Our son helped me with the fitting and bracket mounting since the panels are 26lb and awkward.  They went up very easily and the VHB tape worked well on most of the brackets.

We removed the panels leaving the brackets for me to secure further.  We decided to put two screws in each one and put a lap sealant completely around each bracket:

But there was ONE bracket that gave me fits.  Trying to put a screw in I hit something very hard and twisted off a head of one screw.  I tried to flip the bracket and another screw would not go in.  Great, now I have 4 holes to fill (maybe some FlexSeal Tape?).  I moved the bracket on the solar panel and was able to mount it finally!

Here are some shots of the panels:

Wiring is next.  I had to build a few MC4 cables to get to the combiner box but that was easy.  They hooked up just great and I was ready to flip the switch:

I go down to the solar panel isolation switch and turn it.  I check the voltage on the wires from the solar panels at the controller.  0 volts?  It should be around 15-20v.  I look at the switch and realize it was already ON and I had turned it OFF!  Ok, really turn it on now.  Now the voltage is 0.2v, still not enough.  I turn the switch off and check the voltage on the panel side.  18 volts!  Turn the switch back on.  0.2v.  OK.  That is enough for the night and I am losing the sun.

The next day with good sun there was still the same issue.  Time to call Blue Sky.  I talked to Ryan and he was extremely helpful.  He said it sounded like some type of wiring issue.  I wired the panels directly and not through the switch, same issue.  I was perplexed and Ryan was also.

On the controller, there are 4 places to attach the 2 gauge wires.  A positive and negative to/from the battery, which I knew was working fine since the monitor was working.  Another connection point was from the solar panels (PV – photovoltaic).  I looked at those connectors and saw something.  The wire I was using is stranded and about 3-4 of those strands didn’t fit in the negative connector but pushed out to the side and actually touched the positive connector!  There was the short!

I bent those wires away and the controller came to life!  I was slightly embarrassed but pleased that it was working.

Now I get to play with tracking the in and out of solar power energy.  As a non-scientific empirical test, I disconnected from shore power, turned on both Fantastic Fans and let it run all night.  In the AM I had 84% battery capacity remaining.  Once the sun started hitting the panels, the energy started flowing.  Here are some screenshots of the monitor at a peak time:

It shows the panels charging up the batteries just fine.  The batteries were fully charged up around noon that day.

I am pleased with the performance and very pleased that it is done!

Here are a couple of shots of all 3 panels on the roof:

Many thanks to the numerous blogs, videos, information that I used to plan and execute all this.

Starting the solar install

I have been wanting to put on solar for quite a while.  The tax incentive was expiring at the end of 2016 so I had to get on it.  I started getting parts in July which took a bit of research.  I will put my parts list at the end.

Unfortunately, we have had another project to work on.  Prior to leaving on our full-timing, we had to redo our house shower.  Partially to let our son have a nice workable shower and also to have it ready for resale when that comes to happen.  We have finally got the shower done:

This means I can now devote more time to the solar!  Yes!  The first thing was to figure out what to do with the batteries.  We currently have two 12v AGMs in our battery boxes.  In our vintage of Airstream (2012), the boxes are on either side of our propane tanks and are actually inside the trailer with doors to get them in and out.  Newer Airstreams have the batteries outside in a box directly behind the propane tanks.

I researched how to create a box for our batteries in our little (storage) box that is behind the propane tanks.  It couldn’t be done.  I was resigned to have only two batteries in their original locations.  However, there is another wrinkle.  We have thought about replacing our front couch with recliners.  This would not be possible with the battery boxes sticking into the habitable area.

In all the research of other peoples’ Airstream solar installs, I came across AStreaminLife.  Steve and Courtney have a Classic like we do with the same couch.  They had AMSolar do their solar install and were able to put 4 Lifeline AGM GPL-4CT batteries under their couch and still use the couch as it is.  Here is a Youtube video about it.  That was the plan.

Here is the battery bank as I will put them in the trailer under the couch.  I have them on a board to help distribute the weight and a strap to help them not move around too much.

These are 6V batteries and each has 220 amp hours but the way this works is that I will connect two batteries in series giving 12v (you add voltages in series) and 220ah then I will connect those two 12v serial connections in parallel giving 12v and 440ah (you add amp hours in parallel).  This is double our old setup and should be.

Here are two pictures.  One shows a single battery putting out 6.49v and two in series putting out 13v.

Now I have to clean up the area where the batteries will go.  Airstream was not real neat and clean in their wiring.  They figured out of sight, out of mind.   Here is what I started with:

The two black boxes are where the old batteries were with a door on the outside.  Those need to be removed.  The silver item is the inverter and it will have to be reconfigured somewhere else.  Additionally, I will clean up the wiring and put it on the front wall to get it all off the floor.  There is also a subwoofer to put in somewhere but that should be easy.

Here is a view of the old battery boxes from the outside and inside after my modifications:

I covered the inside with aluminum and will insulate between the inside skin and outside door.  I will update once I have the wiring done and the batteries in.

Parts list:

  • Blue Sky Energy SB3024IL MPPT Charge Controller
    Refrigerator Vent C-Box
    Cable 2Ga 10 feet
    High Current On/Off Switch (shipping 12.00)
    50′ Solar Panel Extension Wires with MC4 connectors
    Grape Solar GS-ZB-Fab1 Feet Z-mount (Qty 3)
    Renogy MC4 tool
    Renogy MC4 Male/Female connectors (5 pair)
    Solar Panels GS-S-160-Fab8
    1/4″ Copper Lugs
    Bussmann CB185-40 Circuit Breaker
    Blue Sky Energy IPNPRO Pro Remote
    2 Ga 600 amp cables
    35mm Rocker Foot Mount Set
    Lifeline GPL 4CT Battery (Qty 4)