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Installing the RV Solar System

Food for Thought Part 3
Installing the RV Solar System

In this article we are going discuss how to install the RV Solar System.

We'll assume that you've made wise choices and have selected the best solar modules, solar panel mounts, cabling and charge controller that you can afford. Now it's time to plan the installation.

Planning the Installation

When we do a solar install we spend a considerable amount of time planning the installation and determining our wiring pathways. A little extra effort in the planning stage will pay off big in the end.

Kyocera 130 on Cab over truck camperThe first thing that you'll want to do is to seek out a location(s) on the roof where you can mount the solar panles where they won't be shaded at anytime during the day no matter which way you park. If this is not possible select a location where you'll receive minimal shading. Shade kills your output.

Raised roof vents, raised TV antennas or satellite dishes can be a source of hidden shading that will totally wipe out the output of a solar panel. One of my 135 watt Kyocera modules gets a little early morning shading from the roof AC but by 9AM the sun is up high enough in the sky that the panel spends the rest of the day in full sun.

Pictured above: A Kyocera 130 installed on the curb side of a cab-over truck camper. Theres not a lot of real estate on the roof of truck campers. As long as this camper parks curb side south there will not be any shading on the solar panel.

Solar current routed thru Fridge ventAfter you've decided on the perfect location to mount your modules you'll need to look for a way to route your cabling into the RV. Sometimes entry thru the fridge vent is the best option. We find this true on smaller rigs or rigs where the battery bank is located near the center of the coach. On large rigs sometimes the holding tank vents are the best choice. Most all of the big 5th wheels we work on will have a tank vent towards the front of the trailer and the batteries are usually near the front. Whichever entry point you use make your wire runs as short as possible to avoid voltage drop.

Pictured right:  We got lucky on this install. Solar output run thru fridge vent to the battery compartment which was located in a compartment adjacent to the fridge. This made for a very short wire run to solar controller and then to batteries.

Next you'll want to determine the location for the charge controller. The charge controller should be as close to the batteries as possible but not in the battery compartment. Battery gases can corrode and over time destroy the electrical circuits in most solar charge controllers.

If you're installing a flush mount controller such as the Blue Sky Solar Boost 2000E you'll be limited to interior coach walls or cabinets. If you are installing a controller with a remote display you'll have a lot more installation options. Controllers like the Blue Sky Solar Boost 3024iL or the Blue Sky Solar Boost 2512iX can be installed in the underbelly near the batteries and the remote display can be installed inside the coach.

Lastly we'll want to determing the paths for all the wiring. Somehow there is always a way to find little nooks and cavities to run the wire from the solar panels to the charge controller, then from the controller to the battery bank. Running the wires is often the most time consuming and frustrating part of the install.

On to the Installation

When we do installs we are a two man team. I'm usually on the roof and my brother is doing the ground work. For this install we'll assume you're doing the solar installation solo and that your installing Kyocera 135 watt solar panels with a junction box.

First let's mount the solar panels. If you've purchased the RVSC Dual Tilt Solar Panel Mounts or the "Smart Feet" Solar Panel Mounts you can mount your modules in a shade free area and then run the wire. If your using fixed Flat Z Mounts you'll need to run the tray cable from the location of the charge controller up to the roof.

Solar Combiner BoxWith the solar panel upside down on the roof insert the tray cable thru the waterproof strain releif that was previously installed in the junction box. Moistening the end of the cable makes it easier to push the cable thru the strain releif. Connect the red wire to the positive and the black wire to the negative terminal. Close up the junction box and tighten the outter cap on the strain relief. If you are installing 3 or more solar panels (if using Tilt Mounts or Smart Feet") it's a good idea to install a fuse in each junction box. If using flat mounts install a fuse for each wire run either in a dry location or in a combiner box.

Pictured above A home-made waterproof combiner box with positive and negative buss bars inside. Each solar panel is routed thru the combiner box with 8 gauge then a single 8 gauge cable is then run to the charge controller. The above combiner box is on the roof of my 5th wheel. Feeding the combiner box is 1 Mitsubishi 110 on medium tilt mounts, 2 Kyocera 135's on large tilt mounts and 1 Zamp 145 on flat mounts controlled by a Blue Sky Solar Boost 3024il with IPN Remote display and a IPN Pro Remote display with shunt. During peak conditons this system produces between 32 to 34 amps.

Next turn the solar panels over and fasten them to the roof. Cover the tops of the fasteners with your choice of roof sealant. You'll need to cover the solar panels for the next step so cut out some cardboard from the solar panel shipping boxes and tie, tape or clamp the cardboard to the top of the solar panels to block out sun light. Secure loose wiring on the roof and along the route to the charge contoller.

Now let's install the charge controller. If you purchased a flush mount in coach controller make your cut out a tiny bit larger than the template that was included with the controller. This gives you a little "wiggle room" to get the controller straight on the wall. If the controller requires battery power before solar power make that connection first. The positive side of the wire from the controller to battery needs to be fused at the battery. Then make your solar input connections and uncover the solar panels.



This article is in progress... please check back in a day or so for more.