DIY Compact Weather Proof Combiner Box

[Bushwhacker]

After having a look around for a combiner box I came to the conclusion that most manufacturers want you to put their product in a sheltered location. I have been brought to believe that it is desireable to place a combiner box close to your solar panels to save on wire and keeping the fuses close to your panels as well.

I didn't want a bulky combiner box that wants to live indoors so I decided to make one. I found a similar idea surfing the net one day but decided to try to improve on it. Here are some pics and short descriptions of my project.
http://s682.photobucket.com/albums/vv190/covetedcrown/DIY%20Combiner%20Box/

Questions, comments and suggestions are welcome.

Cheers!
BW

[DamonHD]

I think I've misunderstood what you're doing, but I've used something vaguely like this:

http://www.maplin.co.uk/Module.aspx?ModuleNo=98625

ie designed to protect mains voltages from weather, so easily good enough for the low DC voltages for my off-grid solar.

Rgds

Damon

[DanG]

If I remember correctly the point where the PV down feed cables exit their run should be monitored by a ground-fault interrupter module - the grid tie system I decommissioned has/had ten inputs each with its own interrupter circuit, then the primary feed out of that 'control module' up to the inverter... 

[Bushwhacker]

Same basic concept for weather proofing Damon. The junction box I'm using is rated for wet service areas in food processing plants or car washes etc.

Dan I'm afraid I'm not following your explanation. I'm using the combiner box to gather the leads from multiple panels or strings of panels. Each panel or string is fused for protection and the heavier output wires from the combiner box run to the charge controller.

I'm still small fry on solar generation so being able to hook up 8 panels is plenty of capacity for me. I have lots of grounded metal goodies up higher and quite close to the solar panels so lightning strikes are not a concern.

If I'm missing something here please fill me in as I'm a big fan of 'safe systems'.

Cheers,
E

[DanG]

http://homepower.com/view/?file=HP123_pg102_Code_Corner

Essentially a small DC breaker that monitors the + and - in relation to ground with the main PV output slaved to it, get 1/2 an amp flowing where no current is meant to be the main PV string output is isolated.

I'm not rabid about using the modules - I think they are code on any residential system.

Hopefully someone with better info will post.

[Tritium]

Same basic concept for weather proofing Damon. The junction box I'm using is rated for wet service areas in food processing plants or car washes etc.

Dan I'm afraid I'm not following your explanation. I'm using the combiner box to gather the leads from multiple panels or strings of panels. Each panel or string is fused for protection and the heavier output wires from the combiner box run to the charge controller.

I'm still small fry on solar generation so being able to hook up 8 panels is plenty of capacity for me. I have lots of grounded metal goodies up higher and quite close to the solar panels so lightning strikes are not a concern.

If I'm missing something here please fill me in as I'm a big fan of 'safe systems'.

Cheers,
E

Here is a link that should explain. It is a diagram from Midnitesolar.  The 1A breaker is a Ground Fault Breaker. There is a lot of good information in their wiring diagrams. My system is not grid tie and I use a common negative, ground tied to earth at only 1 point.

http://www.midnitesolar.com/pdfs/dc-gfp50-300.pdf

I also added Delta lightning arrestors at my combiner box and where my run enters the house.  http://www.deltala.com/products.htm

Thurmond