wood frame mounts

ws9876

about the Canadian Solar 310 watt mono panels... do they have threaded holes on the back to run bolts into? what size?

BB.

Drilling holes or not--That is usually a warranty issue (if panels are cheap and/or purchased without warranty, then that is not an issue).

Of course, holes can weaken the framework, so be careful of the location and size of holes.

Doing wood frame mounts, if using pressure treated lumber, make sure you purchase hardware that is compatible--Pressure treated lumber is much more conductive (typically some sort of copper solution) and can corrode older/non-pressure treated rated hardware.

-Bill

Photowhit

ws9876 said:

about the Canadian Solar 310 watt mono panels... do they have threaded holes on the back to run bolts into? what size?

Most  will have information on the layout/mounting holes on their info sheet. Most will have holes for mounting. I recently picked up  some  larger panels (Q-cell?) from a  utility install and they had mounting holes. Let me see if I can find a  ling to your "Canadian Solar 310 watt mono" panels.

So here's  a link to the info on CanadianSolar 310ms panels

https://www.canadiansolar.com/upload/a8809bc5e67815f0/458cffa3d74f0690.pdf

It includes this engineering drawing;

The hole radius is 4.5mm so diameter is 9mm, should be 5/16ths  bolts to install.

You  may also find installation instructions from the company. I think this is your install instruction sheet;

https://www.canadiansolar.com/upload/0ea8d0f757e1236f/10b409d715356705.pdf

If not, hunt around on this page for it;

https://www.canadiansolar.com/downloads

You can make simple mounts from aluminum angle. ad mount to wooden 'joists'. I used 1/8th" aluminum angle and they still look good after 7 years. Wooden frame work has been through 60mph straight line winds and 18" snow load. with no problems yet, knock-on-wood!



If you make a template and drill single mounts for both panels, with the spacing you want between the panels, you will end up with uniform spacing. Much easier than single mounts (which I did a few, my first time in 2004). This is actually a photo when I sold my array from  2004 system,  I was worried about the reaction between the aluminum and the pressure treated wood from 2003-4. So I added a spacer.  I also did some without the spacer  and  they    were   fine in   2012  when  I  sold the system so I didn't  bother with my new system. These were 3/16ths 1.5x 1.5 angle, I used 2x3  1/8th inch on my current array. Much easier to work with.



I  used 5/4 decking boards for my 'joists' on my current array. it  was a reaction  to the poor quality 2x6s that were available. The decking  was #1 or prime boards. Only small intact knots. I used  sections of 4x4's between cross members of 2x8s  (maybe 2x10s) Note I have a very nice wind break behind the array! Might alter my design without it!

The 4x4s  are earth contact  pressure  treated, there are  different levels of pressure treating. They are also below the frost line  at 4'  with concrete at the bottom. It was recommended to me by  an  engineer not to place them in concrete  to ground level. If you do  this creates a fulcrum point  and pressure point for them to break. Note there are double  cross  members  above and  below.  This allows for easy installation.

Note only the far right joist is attached at the top. So the spacing is created by the panel mounts no forcing them into compliance. Once done I used a crow bar to pick them about 1/2" off the upper cross members and mount to 4x4 pieces sandwiched between the cross members at the top. This worked surprisingly well.

I had to go to 16' joists as the panels were just taller than 12 feet. I asked my engineer brother what he thought about adding  another row of panels, and he said it should be fine, and I have since added 4 more.

Power  center and  battery are under the edge near the home.


They have handled a 18" snow load, so I think I'm good, though I worry a  bit about the top row as they age, this was 6 years in and they did fine.


Hope this  helps or gives you ideas!

ws9876

thanks for info

btw....if you wanted to convert mc4 to straight Romex , is there a cheap fitting for that ..I dont want to cut off the mc4..

thanks

Photowhit

ws9876 said:

btw....if you wanted to convert mc4 to straight Romex , is there a cheap fitting for that ..I dont want to cut off the mc4..

Romex  is a brand, but usually refers to house wiring wire/cable covered in outer plastic. I am not aware of any that is rated for UV exposure/outside use. You will likely want to use a combiner box and can run a single pair of wires to your charge controller. Here's my double combiner box, using fuses instead of breakers;


From the combiner box to the breaker box I use THHN in conduit.

USE2 and PVwire are rated for outside exposure, If you don't want to buy premade cable, you can make the connections your self. There are reasonably priced good crimpers for MC4. Buy the anvil type for a few dollars more than the hinged type(around $30). USE2 is almost always 7 strand is, and is a pain to crimp, but often cheaper. If you want to use it, I'd suggest stripping the cable as normal then clipping 1 strand, and guide the other strands into either side of the crimp. Like I said an PITA!

Note you only have to do one side of the MC4 as the side coming into the combiner box is going straight into the fuse or breaker. I think I bought 2 - 100 foot MC4 extension cable figuring it would be all the wire I needed. I bought off eBay cheaper than I could find the wire. I checked their connectors and found they had been soldered instead of crimped so I replaced them, soldered connections don't hold up well with vibrations and aren't to code unless they are crimped first. 

Where are you located? I would be willing to lend you a MC4 crimper (crappy hinged style paid $70 back in 2004!!!!) and might be able to help with some wire. I pulled a couple systems (at least 1 had the correct wire...lol) and saved the wire and I always seem to have some around, though I'd have to get something for any new wire.

zozomike

Very nice documentation photowit.
Btw, I am also upgrading, and found these on ebay, ordered a sample and quality is great. Solar Panel Mounting Bracket Photovoltaic Panel End Mid Clamp Kit For Roof

( 133282943602 ). I bought them for like $2.08, a month ago, now they are up to $3 something. Hard to buy stainless bolts for that and with clamps you do not care about holes as long as you are in the support zone. 

Ralph Day

If I might add, if you're drilling holes in the panel frames...towards the cells then get a hardwood block that fits between the frame and the back of the cells.  That way when the drill bit breaks through the aluminum frame material it won't run into the back of the cell.  Don't ask me how I know.

The same block used for the entire job.  If you have someone helping who thinks they won't damage a panel...give them one too!

Rlaph

mcgivor

Ralph Day said:

If I might add, if you're drilling holes in the panel frames...towards the cells then get a hardwood block that fits between the frame and the back of the cells.  That way when the drill bit breaks through the aluminum frame material it won't run into the back of the cell.  Don't ask me how I know.

The same block used for the entire job.  If you have someone helping who thinks they won't damage a panel...give them one too!

Rlaph

Happened to you too did it? Drilling through thin material sucks the bit in fast, good advice based on experience.