It took five and a half hours of non-stop work in 95 degree weather, but with some help and a lot of sweat and sawdust our 200 watt solar array is putting out 12 amps of sweet, sweet current. We can now camp pretty much anywhere for at least 2.5 weeks, limited only by our water supply.
WARNING: GEEKINESS TO FOLLOW!
For those of you who care to do it yourself:
- Make sure you have the correct parts.
- Working solar panels (check with a voltmeter!)
- ‘Feet’ or rails for mounting the panels
- Charge controller
- Sufficient length of #10 stranded wire, make sure the wire is ‘high heat’ or 105C thermoplastic (THNN or THWN). Heavier gauge wire is okay, but is probably overkill.
- Battery ends for your wire
- Screws, silicone sealant, adhesive sealant (like Dicor), fuse, “D” shape wire holders, nuts, bolts, drills, bits, etc.
- Determine the placement of your panels on the roof, considering your desire for maximum sun exposure (and minimum shading), proximity of the panels to each other, and proximity of the panels to the area where you will run your wiring into the RV. Make sure that your panels don’t short out during installation! Always assume your panel wires are hot and keep positive and negative ends from crossing!
- Determine the path of the wiring. This is what takes a while, and is one of the big differences between an ‘it works’ job and an excellent job. It’s also one of the main reasons why we worked with a professional on the installation. Most people end up running their wiring into the RV through the refrigerator vent. This frequently means cutting a reasonable size hole in the screen over the vent (to be closed later) and running wiring down behind the refrigerator. We ended up running our wiring down behind the refrigerator and to our charge controller which was mounted in a cabinet next to the refrigerator. This necessitated cutting a hole in the wall of the cabinet. The wiring from the controller to the battery ran back through the same cabinet hole to the rear of the refrigerator, and then down through a hole in the metal floor of the refrigerator control area. That hole led behind a drawer underneath the refrigerator and snaked underneath our dinette seat until it hit the center of the dinette. Then, to get around our propane tank we cut through the bottom of the RV and ran the wiring under the RV to our battery box. The key point: If you didn’t see our panels or charge controller, you would have no idea that there was 36 feet of new ten gauge wire snaking through the RV.
- Attach the feet / rails to the solar panels
- Open the black box on the panels and make sure that only #10 stranded wire (or larger) has been used to wire the panels. If no wire is present or if incorrect wire type has been used, go ahead and wire the panel yourself, following the diagram on the black box. In almost all cases, your red wire attaches to the 12V positive terminal and your black wire to the 12V negative terminal. Make sure that the hole from which your wires emerge out of the box is sealed. Use a waterproof manual seal or silicone sealant. If you have multiple panels, you almost always will want to wire them together in parallel. Leave an extra length of wire (a “service loop”) underneath each panel so you can service individual panels later on without having to dissemble a lot of wiring.
- Flip your panels over (face up) and determine final placement. (Try to place your screw points over roof studs.) Mark the area around each point of contact between a foot / rail and the roof.
- Thoroughly clean the roof in each marked area. Put Dicor or another adhesive sealant under each foot or rail, and let the foot or rail lay down into the adhesive sealant. Let the adhesive sealant bubble up through the screw holes. Screw the panels down into the roof using short (3/4″) screws. The adhesive sealant should hold the panels in place, but the screws provide extra protection.
- Use the “D” shape wire holders to tie down your wiring on the roof, keeping it relatively taught (see photo). Seal all screw points with Dicor.
- Time to run the wiring into the coach! We’ll assume you’re running through the fridge vent. If you haven’t already done so, remove the fridge vent cover and peel back a decent size of the mesh screen. (We peeled back ~8″ x 4″. Make sure you can lay it back down later for reattachment.)
- The tough part: Run the wire along your predetermined route, connecting to the charge controller and battery. Do not run wiring behind (on the coach side of) your refrigerant pipes.
- Seal any holes that you made, make sure you have no loose wiring (loop loose wire and use “D” clamps to tie down), put the vent screen back (tie it back with small zip ties) and smile because you are getting power from the sun.
posted by jay