E21C Solar Panel Installation V.2

[JohnK-ESC]

Since Beep's Solar Panel Installation E21C thread in Problem Solving became a thread about pole mounted solar panels on E19s and MPPPT vs PWM controllers, I'm starting a new thread here about a real in-progress E21C solar panel installation.

Two guiding principles for this installation are: 1) all primary structure is bolts and nuts through the roof, and 2) prevention of panel tear off and wind updraft damage created by oncoming aerodynamically dirty traffic.

Streetside roof thru bolts with 3 inch HDPE doublers and 2 inch SS fender washers are between peeled back insulation and fiberglass roof in street side upper cabinets.

Forward curbside roof thru bolt with 3 inch HDPE doubler and 2 inch SS fender washer is between the shower shell and fiberglass roof accessed through a 3 inch hole in the shower ceiling. Aft curbside thru bolt with 3 inch HDPE doubler and 2 inch SS fender washer is between peeled back ceiling insulation and fiberglass roof.

All aesthetics are restored to factory visuals except for the bath ceiling which has been restored with an aircraft style inspection hole plate.

I ordered a 200 watt Renogy panel to augment ETI's original 190 watt GoPower solar panel thinkng the Renogy had a 45 mm frame. The frame is actually only 35 mm. I should have sent it back but instead reinforced it with corner braces and doublers in the long crosswise frame span. The 35 mm frame minimizes how much real estate one has available to place fastening hardware after reinforcing hardware has been added. My bad for not returning the panel and procuring one with a 45 mm frame.

Electrically, this is a simple two paralleled panel installation to charge a single 230 amp/hour LiFePO4 battery using ETI's original GoPower PWM solar controller with a Victron monitoring shunt and the original WFCO non-lithium converter/charger. This is not some exotic high powered system to run high powered air conditioning and an all electric appliance trailer. My goal is simply to prepare for an eventual DC compressor fridge and have enough electricity to heat and light up the cabin and run the water pump during 3 1/2 season boondockng without having to worry about battery charging.

Panel roof mounts are T4 galvanized steel flashing brackets from Ace Hardware at 3.99 each and stainless steel bolts, screws and nuts. The street side air dam is .040 2024 T3 aluminum. The forward air dam is pipe freeze protection foam tubing which I plan to fasten with VHB 5952 tape. If it gets torn off and flies away it won't hurt anyone.

ETI recommends Proflex lap sealant which I will but have not yet applied. Cable to the Y paralleling connectors is is 8 awg.

Following are some photos of my work in progress.

John

 

[Ron in BC]

Nice well executed installation.

Mirrors my views on a robust installation. In my view there's no substitute for through bolting.

I've been doing the inspection hatch routine on boats for years when I needed access to a hidden area. Afterwards the inspection plate or cover goes on and no one gives a second glance.

Ron

 

[Centex]

Looks stout!

Just curious and always learning by asking ....

Is there a particular reason for threads-up through the roof vs threads down with just a bolt head bedded in sealant (TBD) on the roof?

Also, are these sheet metal screws, and if so do they penetrate both layers of the hollow panel frame extrusion, or machine screws with nuts inside the panel frame extrusion?

 

[JohnK-ESC]

Alan, the ETI installed solar panel on the aft end of the roof has the bolts coming up through the roof from the inside and are trimmed off above the nuts. I simply wanted to follow factory practice on this. Since this photo was taken I have trimmed my bolts down 3 threads above the nut. I’ll also be sealing with clear Proseal lap sealant rather than with Dicor because Proseal is what ETI recommends. Also with the nuts up on the top side they can be inspected for security which I have been doing on a regular basis on the aft panel.

Regarding the hardware you have circled on the photo, they are all stainless steel machine screws with nylock nuts on the other end through both walls of the frame. There is not one single sheet metal screw or one blind fastener on the entire assembly. I have knicks, cuts and bruises on my hands and arms to show for having gone with bolts and nuts as opposed to sheet metal and blind fasteners.

Thanks for checking.

John

 

[iamunique127]

Clean looking instal.

I've found pipe wrap to weather poorly so you may find it needs to be replaced regularly.

 

[Centex]

Alan, the ETI installed solar panel on the aft end of the roof has the bolts coming up through the roof from the inside and are trimmed off above the nuts. I simply wanted to follow factory practice on this.
......

Regarding the hardware you have circled on the photo, they are all stainless steel machine screws with nylock nuts on the other end through both walls of the frame.

Got it, thanks!

 

[JohnK-ESC]

Clean looking instal.

I've found pipe wrap to weather poorly so you may find it needs to be replaced regularly.

Thanks for the heads up Lyle. I'll keep that in mind and be looking for alternatives. The air dam and what to do about it is a tough one. I almost wonder if I need one with the panel leading edge 3 feet aft and only 9/16 inch clearance above the roof at the center of the long span.

John

 

[JohnK-ESC]

Today was test drive and solar charge test day. Normal towing speed is 62 MPH but for testing, towing in 12 MPH NNW wind driving both east and west I sustained speeds between 70 and 75 MPH several times for up to 3 minutes. The airflow diverters retained their original angles and the pipe insulation foam air dam remained in place and intact. Before and after test drive photos attached.

Solar charging amps with the 190 watt and 200 watt panels in parallel through a simple PWM controller prior to solar eclipse were 17+ amps. At 86% eclipse + high thin cloud cover charging amps dropped to 1.25 amps. Before and during eclipse solar charge photos attached.

I'm ready to go boondocking.

John

 

[rubicon327]

Thanks for the heads up Lyle. I'll keep that in mind and be looking for alternatives. The air dam and what to do about it is a tough one. I almost wonder if I need one with the panel leading edge 3 feet aft and only 9/16 inch clearance above the roof at the center of the long span.

John

John: I think you might be unsatisfied with that foam fairing piece in the long run. Just food for thought you might consider these Redarc fairing mounts. If you have the room they could be placed under the leading edge of your panel as intended or (as I plan to do) place them just in front of the panel. Mount with VHB and a perimeter bead of Proflex.
https://www.etrailer.com/Accessorie...38wNtonlNb5BwAU-qzy8zQWOqSt_AKGMaAvV5EALw_wcB

 

[JohnK-ESC]

John: I think you might be unsatisfied with that foam fairing piece in the long run. Just food for thought you might consider these Redarc fairing mounts. If you have the room they could be placed under the leading edge of your panel as intended or (as I plan to do) place them just in front of the panel. Mount with VHB and a perimeter bead of Proflex.
https://www.etrailer.com/Accessorie...38wNtonlNb5BwAU-qzy8zQWOqSt_AKGMaAvV5EALw_wcB

I appreciate and thank you for the suggestion Rubicaon327. Iamunique also mentioned that this pipe wrap does not weather well. I'll consider your and other options when this $4.50 pipe wrap quits performing. I/m not sure this panel with the airflow diverters and only 9/16 inch clearance above roof surface even needs an air dam.

John

 

[rubicon327]

I/m not sure this panel with the airflow diverters and only 9/16 inch clearance above roof surface even needs an air dam.

I would agree it probably does not need one especially with your setback distance from the front edge of the trailer. My front panel will be close to the front edge so will have frame reinforcement and fairing.

 

[JohnK-ESC]

It’s wise to reinforce these frames. I used existing holes to fasten in corner braces as well as long span doublers. This Renogy frame does have a very small hole at the center of both the long spans bottom flange which is labeled as a grounding point. I left that hole alone and did not drill any holes for reinforcement purposes.

John

 

[JohnK-ESC]

This installation achieved another benchmark this week with a camping trip which included 30MPH+ crosswinds on two lane roads passing oncoming trucks. After the trip, looking for cracks in the mounting feet and brackets and panel fastening locations I found no damage of any kind to the mounting structure or the panel. Even the foam air dam remained firmly in place.

Dealing with shade and cloud cover I was still able to recharge my 230 AH LifePo4 battery to my daily goal of 80% state of charge, even after brewing a large pot of coffee off my inverter for a neighbor who had just bought a new electric coffee maker but had forgotten to load their generator for their outing. Although the solar array performed well with the factory PWM solar charging controller, I have decided to do the right thing and switch to an MPPT controller for the long term.

John