By Bob Kelly 2019
Updated March 24, 2022
This kit from Amazon is a good start. It contains three panels, support feet, a through roof appliance with compression connections, wire from the panels to the controller, a controller, and wires from the controller to the batteries/inverter.
Additionally, you will need two in line automotive fuses, a tube of Dicor and 3M VHB tape. I suggest, and offer for sale, mounting pads for the Z bracket feet for the Renogy panels, so you have the option of removing the PV Panels from the RV. Shrink tubing, dielectric grease, crimp fittings can be useful, and will result in a professional looking job. A 3M scrubber pad, terry towel and denatured alcohol are mandatory for a spotlessly clean roof on which to mount the solar panel (PV) feet.
Panels can be located on the RV by using the cardboard from the packaging they were shipped in to mock out the locations of the solar panels. Panels can be connected in either a serial configuration, or a parallel connection. I prefer the parallel connection. Parallel connections increase the amperage but leave the volts alone, serial connections increase the voltage, but leave the amperage alone. A serial connection of three panels can result in an output of 57 Volts DC. Four panels can result in an output of 76 Volts DC. Review the specifications of your controller.
A battery management system (Victron) has nothing to do with the installation of a PV (Photo Voltaic) system. It is not necessary to install one at the same time as a PV system, but a battery management system lets you know what your state of charge (SOC) is at any moment. There is no necessity to purchase one with a monitor. The Victron Smart Shunt, no monitor, works off Bluetooth, and is superior. The Bluetooth software dispalys all the information at one, without paging through screens,
Mount the Z brackets (feet) to the Renogy panels. Use blue Locktite on the connectors. Mount the mounting pads loosely to the Z brackets. Affix the 3M VHB Tape to the bottom of the mounting pads. Remove the protective paper from the VHB tape.
Make sure you clean the roof where the feet/mounting pads will be affixed. Remove any dirt, grease, wax, algae, or other substances using undiluted denatured alcohol. The 3M scrubber will be a great help. Make sure the roof is clean and dry with the terry towel. It helps if you mark the perimeter of the cleaned roof with a pencil.
Place the long axis end of the panel assemblies on pieces of 2×4 wood to keep the feet from touching the roof. Be careful, the VHB Tape is permanent, and is much like using contact adhesive. You only get one try when mounting something with the tape. Align the panels for correct orientation (the panels must have their long axis fore and aft. There is too much curve in the roof for the Z brackets, mounting brackets, or any other bracket to be affixed properly) and mount the PV Panel assemblies in place.
If using mounting pads, unscrew the PV Panel assemblies from the mounting pads, lift the PV panel and caulk the roof/mounting pad connection with Dicor to eliminate any possibility of mechanical separation from ice formation. Re-attach the panels using blue Locktite on the connectors provided.
Prepare the roof penetration appliance with VHB tape on the base. Leave the protective paper on until the very last moment.
Roof penetration and chasing wires is the most difficult portion of installing a new PV system. If you have a Zamp system already installed, either install a rigid Zamp panel directly; (they plug right in), or use a rigid solar panel with a MC4 fitting connector and a gender adaptor. Rigid panels are more effective, and are substantially cooler than flexible panels that mount flat on the roof. Non- Zamp panels are much less expensive. Wires to the roof penetration/hookup can be held in place with Dicor. The PV output wires need not be physically attached to the roof with a mechanical device.
I have had success in locating voids in the 4” of insulation in the roof by removing the face plate and any gauges of the ‘One Place’ to access the area to the rear of the ‘One Place’ in newer RV’s. I examine the area where the roof curves to meet the side of the RV. When the void is located, locate the flattest area of the roof accessible, and drill a 1/16” hole to the furthest rear portion of the void. If you make a mistake the 1/16’ hole is easily caulked. Locate the hole on the outside of the roof, and drill two holes in the roof at the site of the 1/16” hole each of which should have a slightly larger diameter than the diameter of the panel to controller wires.
In older RV’s with a roof mounted refrigerator exhaust , the supply wires were run through the roof mounted vent, down the rear side of the refrigerator flue space, through the plastic base of the refrigerator flue, near the copper propane tubing, and then behind the sink and cabinets, or under the dinette, as model variants dictate. In newer RV’s the run is essentially the same, you are simply making the hole in the roof instead of utilizing one.
I use a fiberglass fish rod, about 4’ long, to run the wire from the roof penetration, down the flue, through the base of the flue and to the rear of the cabinets.
Run the connector wires, bare end, through the compression connection of the roof penetration appliance, through the holes in the roof, down the refrigerator chase, through the area under the cabinets to the location selected for the controller. Do not caulk the roof appliance of the holes in the roof, until the very last step. Connect the fittings end of the PV output wires to the PV Panels.
Select the location for the PV Controller. Make sure that there is enough wire to reach the controller from the PV Panels. If the wire is short, generally there is enough left over wire on the controller to battery wires that some from there can be used. If you have a RV without an inverter, you will have to drill holes through the floor adjacent to the batteries. If you have an inverter, the inverter is already on the same bus as the batteries. The output of the Controller can be connected directly to the rear of the inverter, effectively connecting the output to the batteries. Generally, there is a hole or port in the floor of the RV to the compartment the inverter is located in. The wires can be run through that opening. Look carefully, the hole may be obscured, but in every RV I’ve installed a system, there was an opening.
Splice the positive leg of the wire from the PV Panel with the automotive fuse, crimp and use shrink tubing for a secure connection. Splice the positive leg of the wire from the Inverter/Battery with the automotive fuse, crimp and use shrink tubing for a secure connection. Connect the wires from the inverter/battery to the converter, and then connect the wires from the PV Panels to the converter. Please read and understand the manual for the converter. Immediately configure the converter for the type batteries you are using.
Return to the roof and determine how the wire from the PV Panels will lay on the roof, where it will enter the compression fitting, and at what point the wire will enter the RV through the roof holes. Remove the compression fittings from the roof penetration appliance and slide the compression fittings down the wires. Clean the roof in the area of the roof appliance in the same manner as you did for the mounting feet of the panels. Carefully caulk the wires at the roof entry holes with Dicor. Be neat, and do not spread the dicor to the area where the roof appliance will be mounted. Remove the protective tape from the appliance, and mount to the roof. Liberally caulk the roof appliance/roof connection with Dicor. Slide the compression fittings back down the wire, attach to the appliance, and tighten.
Clean the workplace and install all the drawers. The job is complete.
List of Materials for Installation
There are innumerable suppliers in the marketplace. I prefer Renogy. American made, affordable, and so far, long lasting and durable. This list is complete independent of vendor, but does not contain a battery management system, or an inverter, which are separate installs.
Solar Panels (300W)
Dicor Two Pack
30 A Fuse
Milled Aluminum Offsets Three sets @ $30 a set. (Available Here)
Zip ties, Phenoseal, small mounting pads, crimps, shrink tubing, dielectric grease, cleaning supplies (Denatured alcohol, 3M Scrubber pads), tools and misc.