Re: [VAC] Solar panel installation

[Jim Dunmyer <jdunmyer@toltbbs.com>]

Terry,
 The solar panel installation (2 panels, BTW:) is on the Avion, you're
right there. However, I'm not 'stumped', not even 'confused'; here's the
deal:

The first problem to be solved is exactly how to attach the panels to
the roof. My solution was to bend brackets from 1/8" X 2" aluminum,
about 4" long before bending. Exact angle was determined by using an
adjustable try square between the panel and the roof. Length was
determined so as to hold the panels off the roof by about 1 1/2" so they
stay cool, and of course the angles are different for the inside and
outside brackets. Mine turned out to be 85 and 75 degrees, respectively.
Brackets are attached to the panel frames with 2 8-32 RivNuts for each
bracket and SS 8-32 screws. We installed 1/4-20 RivNuts into the roof at
each bracket location and used SS 1/4-20 bolts, SS flat washers, and a
neoprene washer between the roof and bracket and bracket and SS washer
beneath the bolt head. The cables from the panels are secured to the
roof with stick-on dealys that accept a Ty-Rap, and enter the trailer
through the refrigerator vent. Naturally, they go through a piece of
Tygon tubing where then enter the vent.

That took much of a day.

Next problem is how to route the wires from the fridge vent to the
batteries. The Avion has a pair of Group 24 RV/Marine batteries in a
plastic box, mounted under the front couch/bed. They use special caps
that have nipples to attach tubing that vents the gasses through the
floor and bellypan. The battery box has a drain tube that runs all the
way through the floor and bellypan, and the vent tube is routed through
that. The fridge is just behind the door on the curb side, so there's no
direct route between it and the batteries.

My solution is/was to remove the fridge so I can install conduit between
the top/vent area, down to the floor. I didn't really want to let the
wires just hang there, I want to keep them away from the coils, both to
keep them cooler and to keep them from just rattling around. Removing
the fridge allowed me to remove the panel below it that covers a little
empty compartment between the fridge bottom and the trailer floor. We
went as far towards the center of the trailer as possible and drilled
through the floor and bellypan. We ran a short piece of conduit between
the top of the floor and the bottom of the bellypan, used a 'pulling
ell' to make the corner, then ran a piece of 3/4" EMT towards the center
and forward to the electrical connection area under the battery area.
(this is similar to my A/S, where the trailer pigtail attaches to the
trailer wiring) Another 'pulling ell' gets the conduit back into the
belly.

Various issues required that we move the battery box about 3" forward
and 2" towards the side; this required drilling a new hole through the
floor and bellypan for the drain/vent tubes, of course.

Now, any good solar installation needs some sort of control and
monitoring panel. Besides that, I really like dials, knobs, and other
gadgets. The only logical place to mount such a thing is in the end of
the cabinet above the fridge. Due to current and (unknown) future
requirements, I elected to run plenty of wires through the conduits
between the battery and the top of the fridge 'chimney'. IIRC, there's 7
or 8 wires plus a multi-conductor cable with at least a half-dozen 20 or
22 guage wires. The latter is for future addition of a Crusing Equipment
e-Meter or somesuch. Current, immediate plans include an ammeter,
switch, fuse, and the solar controller to be mounted in the panel, along
with a 115VAC meter and a switch for a (future) muffin fan for the
fridge.

Removing the fridge, drilling holes, running conduit, and pulling wires
required most of another day.

Building the control panel will require another day, wiring it will be
yet another day. And we have to reinstall the fridge somewhere in the
process. I'll also be adding a terminal block and some fuses adjacent to
the battery, of course.

My criteria for such work is: would it withstand a nuclear explosion
that would destroy everything around it? I'm happy so far. <>

Those 2 panels, bought for $225.00/each at the Dayton HamVention, give a
solid 8 amps total into a short-circuit during peak times and 2 amps
very early and very late in the day. I should be able to depend on 40
amp-hours or more on sunny days.

Now you know how I can spend most of a week doing what the professionals
claim can be done in a few hours. <>

I'll try to take some pics and post 'em on my Web Site.

                                        Jim