Big Solar on the Tiffin

Started my solar project on the new Tiffin Open Road 32SA.  Putting eight, 160 watt panels on the roof for a total of 1280 watts!   I got the solar pre-wire from Tiffin (which I'll explain further below).   For a controller, I got an Outback FM80.   This controller is MPPT and good for 80 amps and 150 volt input.   It's a very robust looking peice of equipment.

Today's goal was to get the feet bolted on the panels, get them on the roof and uncover the wiring to see what I'm dealing with.   Lucky for me, I had my nephew Alex to give me a hand.  It would have been impossible to get this done without some assistance, so I thank you very much, buddy.

My plan is to have two banks of panels - 4 each, wired in series.  Then they will be joined in parallel to the two wires at the roof penetration.   So what is coming down off the roof is roughly 80 volts and 16 amps.  There will also be a 20 amp DC breaker mounted down below as a shutoff for this power before it gets to the controller.

I played around with laying the panels out without getting shadows.  Of course, that is pretty much impossible, so trying to get few is the goal.  First was as you see here (the cardboard is still on the panels to protect them and so there isn't current when I connect the cables).

 I didn't like that they were all over the place.  My OCD demands symmetry, so I moved a few around.  I like that the center is clear for walking to get to the various items on the roof.
The little white dome you see on the right is where the wiring bundle is supposed to be for the pre-wire. 

I had to chisel off the sealant around the dome and over the screw heads.  The red stuff you see is what I refer to as "project lubricant".  You can't get any project done without it getting smeared on you equipment or tools.

I'm mulling how to do the roof penetration.   Drill holes in the dome, and push the cables threw and seal around them?   Discard the dome and install a roof mount box?

Inside was packed with sealant too.  They must have used an entire tube on just this dome!
The wires were bundled inside, just below a piece of insulated foam.

The wires were all marked with the coach model (32 SA) and the service (solar panel).

A finger for perspective.   Looks bigger than the 10 AWG that the panels are wired with.

And it's a stranded cable.

Inside the cabinet, overhead of the driver's seat, I found the other end of the cable, as well as the set of cables that go down to the battery compartment.    Tiffin intends for you to mount your solar controller here.   It's just unworkable to do this, as while this cable size is adequate to come down off the roof, it is not to run to the batteries.

I'm going to splice these cables together with butt connectors, and take the end of these cables (down in the battery compartment) and hook those to my controller.  Then I'll run new, heavy guage cables from the controller to the batteries.

What's odd is there was about 10-12 feet of cable shoved up in there, and all of it in combing.  Crazy!   I'll cut most of this out, as unnecessary cable length is not what you want in a solar installation.

What's up in there, inside the front cap, it a rat's nest of wires, and no insutation.  Looks like another project is in order to stick something in there to keep the heat down in the front of the rig.

I found other markings on the cable - the standard stuff from the cable manufacturer.  Looks like it's all 8 AWG.   10 AWG would have been more than adequate for how I've layed this out, so 8 is great.

Down in the battery tray, I found the other end of the cabling, stuffed in the side against the wall of the compartment.  There is plenty of slack, so I can pull this wire out of this area and feed it into the compartment I'm going to install the solar controller.

 That's all for today.  More in the days ahead.