Solar combiner box.

[Muddydogs]

Anyone have some pics or links to a DIY solar panel roof mounted combiner box?

My solar is acting up and not charging, I think its the quick connects coming off the panels to the main line on the roof. Figure I need to remove the quick connects and either solder the connections or run them into a combiner box. Since I need to mess with the stuff on the roof I might as well add another panel for a total of 3 at 300 watts so 3 lines coming into the main line is probably to much to solder together plus if I need to replace a panel having all 3 connected together would be a pain so I might as well just add a combiner box on the roof.

[hedge]

Instead of using cable glands, I made my box to accept mc4 connections so the connections themselves became the passthrough to the box and then the panels plug into the box.

[grizzzman]

grizzzman wrote:

Colo Native wrote:
Made my own

Home Depot? I have 4 panels parreled to that same box
I have 4 more glands due to running two #6 pos and neg.
This allowed me to run them down the awning mount.

[grizzzman]

Colo Native wrote:
Made my own

Oops double post

[Optimistic_Para]

Muddydogs wrote:

Thanks for the pic. I'm going this route as well, I have some thick copper and aluminum I can cut down and tap for a couple buss bars. Can't find any waterproof box inlets for the smaller solar cable but I figure I'll get a couple bigger waterproof inlets and just fill the extra space with some caulk once I get it together.

These come in various sizes:

Cable Glands

[Muddydogs]

Colo Native wrote:
Made my own

Thanks for the pic. I'm going this route as well, I have some thick copper and aluminum I can cut down and tap for a couple buss bars. Can't find any waterproof box inlets for the smaller solar cable but I figure I'll get a couple bigger waterproof inlets and just fill the extra space with some caulk once I get it together.

[big_buford]

Just cut 2 mc4 connectors out of a buddys system not charging. I would assume all MC4's are not created equal?

[Colo_Native]

Made my own

[mike-uswest]

I have used two of the AM Solar boxes, and they are quick and efficient.

Mike

[pauldub]

I used one of these.

AM Solar also offers a combiner box that suitable for RVs.

[Muddydogs]

Spridle wrote:
In your case, a combiner box is nothing more than a water tight box with terminal strips inside. You will have to secure the box to the roof. Assuming you have two panels you will need 6 entry glands to keep the cable entry points water tight. A quality box is expensive.
Combiner Box Hyperlink

You could replace your MC-4 connectors because yours are either damaged, cracked or never tightened and water got inside. MC-4 connectors dont leak if they are not damaged and installed correctly. They are used on every commercial solar installation I have seen. Also tiewrap the connectors so they are not setting on the roof in a puddle of water or snow.
Crimp Tool Hyperlink
and the connectors, get the correct size for your wire gauge.
MC-4 Connectors hyperlink
You should replace your two "Y" combiners, water probably got inside.

I would say the problem is the connectors have set for 3 years in water or snow all winter long as my trailer is stored outside, some years I have a couple feet on the roof almost to the point where I start thinking about removing some. I'm sure the Wyoming wind hasn't helped when towing either.

I'm sure everything was tight when I installed it but who knows now? I haven't checked the connectors myself as it was all we could do to get the smallest guy in hunting camp on the roof when I noticed the problem. Once home I pulled the battery's and put the trailer up for the winter figuring I would deal with it in the spring. I'm just trying to get a plan now, pick up supplies and decide if I want to add one or two more panels to the system.

[Spridle]

In your case, a combiner box is nothing more than a water tight box with terminal strips inside. You will have to secure the box to the roof. Assuming you have two panels you will need 6 entry glands to keep the cable entry points water tight. A quality box is expensive.
Combiner Box Hyperlink

You could replace your MC-4 connectors because yours are either damaged, cracked or never tightened and water got inside. MC-4 connectors dont leak if they are not damaged and installed correctly. They are used on every commercial solar installation I have seen. Also tiewrap the connectors so they are not setting on the roof in a puddle of water or snow.
Crimp Tool Hyperlink
and the connectors, get the correct size for your wire gauge.
MC-4 Connectors hyperlink
You should replace your two "Y" combiners, water probably got inside.

[2oldman]

Muddydogs wrote:
After a quick refresher reading I want to stick with parallel as most of the time I'm in shady areas.

I try to find non-shady areas.

[Muddydogs]

Optimistic Paranoid wrote:

Muddydogs wrote:
Thats what I have now on the roof. When you wiggle the connectors I get 14.4 volts when not wiggling them I get 12.3 which is what the battery's are charged to.

I suspect that if you unhooked them and gave them a thorough cleaning with DeOxit, your problems would go away.

DeOxit

I was first turned on to this stuff by an electrical guru I knew. It's worked wonderfully well every time I've used it.

BTW, you know you need a special (inexpensive) tool to disassemble MC4 connectors, right?

I'm sure I could clean them but there's always the next time they don't work and my trailer roof is a long ways up with no ladder to access it. I would much rather take the connectors out of the equation and do it right. Plus adding a third panel will complicate the connectors needed.

A tool would be nice I'm sure but I just did it with my fingers, didn't know I wasn't supposed to be able to without the tool.

[Optimistic_Para]

Muddydogs wrote:
Thats what I have now on the roof. When you wiggle the connectors I get 14.4 volts when not wiggling them I get 12.3 which is what the battery's are charged to.

I suspect that if you unhooked them and gave them a thorough cleaning with DeOxit, your problems would go away.

DeOxit

I was first turned on to this stuff by an electrical guru I knew. It's worked wonderfully well every time I've used it.

BTW, you know you need a special (inexpensive) tool to disassemble MC4 connectors, right?