Solar panels, how high should they be above the roof

[Fisherguy]

Hope to mount my panels this weekend, making brackets out of aluminium angle, how high should they be above the rubber roof? Most commercial brackets seem to have them 1" high, would 2" be better, help with cooling etc with a bit of an angle for water to run off etc?
One panel will be one across the front in front of the skylight, 1 down each side beside the front skylight.
Thanks

[Fisherguy]

On another note, I'm hoping you guys subscribed to this thread...

The Tristar 45 pwm controller has a 'battery sense' connection. The output of the controller will be connected to the output of my inverter which is connected to the battery by 7 ft of 4 ga, is the battery sense connection really necessary?

It sounds like they'd prefer a twisted pair, 16 to 24 ga connected right to the battery, what type of cable do people use?

[Fisherguy]

bigfootford wrote:
Wow, congratulations for finally resorting to getting solar!

Jim

Hi Jim,
Ya, my bud put 2 - 140's on his 5th wheel, his wife watched a lotta TV while we were out fishing and he never had to run his genny once in 3 weeks. (we had a LOT of sun that trip) I had to run mine every day so it's time to finally do this.
Getting 3-120's so I should be good with my 2 Crown CR-235's, wish I had room for 2 more.


Thanks for the link Barry.

Will mount them 2" high min, interesting the Cdn solar manual recommends a 15* tilt, that's quite a bit.

I won't be tilting mine so will stick to the factory mounting spots.

Cdn solar manual

[RoyB]

I like the large 1/4-20 PLASTIC KNOB Rich is using... Of course however PLASTIC and UV rays don't mix well...

I am thinking of going the ALUMINUM UNISTRUT idea going all the way across the trailer roof and securing these sections at the ends close to the side of the trailer roof where you should have something good to mount to. I am not a fan of drilling holes in the roof on my POPUP trailer.

My POPUP TRAILER may have to have a couple of these 120WATT panels mounted after the roof has been raised and locked due to the extra weight of panels. My roof is electric and already has a 13,500 BTU Air Conditioner mounted on the roof...

This is sort of my plan using the across the roof light weight Aluminum UNISTRUT sections. I can slide the mounting nut anywhere inside the unistrut section for the panels... I will use right angle mounts to the side of the solar panels.







The larger 240WATT panel I am thinking about will go across the rear of the roof side to side. This is the one that may be the best to install after the roof is raised as I can get to at least the mounting angles on both sides and the rear by standing on a short stepladder. The inside solar panel mount not easily accessible from the ground can be just a support angle not actually screwed down to the unistrut frame section.

Still in the scratch the head mode here...

Roy Ken

[MrWizard]

The factory holes are in the correct place for panels that are never moved
But when you lift one end of the panel the other end goes down
(Think tail swing on your RV)
If the front holes are six inches from the edge of the panel, and the panel is one inch above the roof, you can't lift the back to tilt the panel
Lift the back one inch the front goes down and HITS the roof.
No tilt
Holes closer to the corner, and brackets that hold higher off the roof
Allow the panel to be tilted
You can mount them as is and never move them
But IF you think, you want to clean underneath or tilt them
Planning ahead saves a lot of rework
Using taller brackets, or extensions on the brackets, getting the panels further above the roof alleviate the problem, without drilling new holes in the panels

[BFL13]

Fisherguy wrote:
What's wrong with the mounting holes the panels come with, how are they not in the 'right' places?
(I haven't got mine yet, picking them up later today.)

Google Canadian Solar installation manual and read Chapter 6 on mounting options. They show where to put the supports for either orientation so the panels don't flex out of shape etc.

They do say not to drill more holes in the frame, which would weaken the frame.

As to warranty, it depends on the Brand I guess, but Sharp said with theirs that it did not apply when the panel was on a mobile platform, only for on a stick house, eg.

[bigfootford]

Wow, congratulations for finally resorting to getting solar!

I mounted my panels just high enough to get a brush under them to clean the roof...
I just used 3x3 aluminum L stock to fabricate my roof brackets. In the panel corners I used 2x2 aluminum L to re-enforce the corners glued and bolt/nutted. Then I mounted my 3x3's on that.

Luckily my camper's front is slightly tilted down so no problem with the pooling dirt and water. Also my roof is arched so my panels are slightly tilted to the side.

I thought I might want to tilt them so I did not secure the panels to the roof brackets with bolts n nuts, I used pins. Never needed to tilt. All the way to Prudhoe bay!





Link to more detail of my install:

http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/24783458/gotomsg/24787554.cfm#24787554

Note how many cells I have on my panels... 100watts each.

Jim

[Fisherguy]

What's wrong with the mounting holes the panels come with, how are they not in the 'right' places?
(I haven't got mine yet, picking them up later today.)

[RJsfishin]

Seems like if they didn't want you drillin new holes, they would put the ones they drilled in the right places. I have never used an existing mounting hole, and I sure don't worry about panel warranty either. Has there ever been a panel go bad on this forum ?? I never read any. And what would it cost to ship one back,...at least .50 a watt ??

Nutserts do not hold up in thin metal,...don't waste your money

One panel I bought was a 1/4" thick for 6" long on all 4 corners,...no reinforcing needed.

[azrving]

I used rivenuts through the frame. Be sure to use anti seize on the threads just in case you dont remove the knobs for a long time. Frames are about an inch or less off the roof. I'm not going to the desert in the summer. Ive seen temps of about 130

[westend]

Fisherguy wrote:
Thanks.
I'm bolting some angle to the frame of the panel using the factory mounting location (I've heard drilling the frame will void the warranty?) and another piece of angle to the roof with a bolt between the two.

No shortage of rain up here normally, dry as a popcorn fart this summer though, stage 3 water restrictions, no lawn watering at all, can't even wash vehicles (or rv's).

Well, I drilled the heck out of my module frame and never thought a thing about it. I don't plan on ever trying to enforce a warranty. I asked about my plans for a tilting mechanism over at the NAWS forum and got reamed pretty good for using anything but the factory holes. The frame with attached tilt has been in use for a couple of years now and is still in good shape.

If you roof is cambered like most, the modules aside the skylight will have a small bit of tilt. The front one could be angled by location of the holes in the mounting bracket (drill the back ones higher on the foot). I live in snow country so tilt or angle while flat is a good thing.

Mr. Wizards suggestion of a nutsert is a good one. It makes it very easy to dismount the module for a variety of tasks. An alternative may be use clamping knobs and just a nut.

Good luck with the modules. You're going to like solar.

[RJsfishin]

Another way to go is w/ a 1/4" x 1" alum flat bar 3" long, pop riveted to the inside of the panel all 4 corners. Then those get drilled and tapped 1/4-20 for the plastic knobs bought at any good hardware.

[Fisherguy]

Thanks.
I'm bolting some angle to the frame of the panel using the factory mounting location (I've heard drilling the frame will void the warranty?) and another piece of angle to the roof with a bolt between the two.

No shortage of rain up here normally, dry as a popcorn fart this summer though, stage 3 water restrictions, no lawn watering at all, can't even wash vehicles (or rv's).

[MrWizard]

i'm going to re do some of mine
2" on the front edge 3" in back
yes water run off , helps keep from making dirt puddles, when stationary water dries up

we don't get very many really good rains that wash the panels

get some "nutserts" aka Rivnuts and the tool for setting them to the panel
using a permanent nut on the panel for fastening to the bracket
makes it easy to loosen the bolt and clean under the panel
or add tilt bars

[Fisherguy]

I'm not getting any mounting brackets, that's why I'm making some, (plus I don't like the idea of Z brackets).