Leak free penetrations and racking system suitability.

[J.P.M.]

I Recently contracted to buy the following system: 16 SP 327's, 4 x 4 in landscape. SP 5000p inverter. roof is 18 deg. slope, 195 deg. az. No shade. Concrete tile. east half of array is over vaulted living room ceiling and inaccessable form underside. west half of array is over crawlspace and accessable from underside. 30 yr. old house. Concrete tile roof about 20 yrs. old. The roof is being independently serviced /repapered/updated prior to solar install. Roofer and solar vendor have agreed to coordinate with roofer flashing penetrations and retiling as panels are installed - a 1 to 2 day job, so I'm told if snagfree. I'm very concerned about the roof penetrations as some of them will not only be out of reach on the finished array, but out of sight and inaccessable. Questions: 1.) Besides good and proper attention to flashing detail(s), are there other things I can do to increase the probability of leak tight roof penetrations ? 2.) Does anyone have an opinion they'd be willing to share about racking systems ? I've heard names like Unirac and Ironridge and others. I'd guess that structurally, they all pretty much pass muster if designed properly. How about things like ease of assembly, robustness, availability, system flexibility. Cost is somewhat important, but not the highest priority by a long shot. I suppose you want nice you pay nice and I'm realistically OK with that. I'm more concerned about finding the best path to a well designed system that has the highest probability of a long, leak free existence.

Regards,

J.P.M.

[thastinger]

I would check your required wind rating (if any) and be sure to get the wind cert from the racking manufacturer for your home ins. I used the Soladeck enclosure for my roof penetrations, it has only been installed a few months but no issues thus far.

[peakbagger]

Be aware that most racking manufacturers do not make the roof flashing or connections to the roof. They basically bolt to a stud sticking out of mount supplied by another company. Quick Mount is quite a popular supplier or the actual roof mounts. Do note that most dealers package the sourced components into a system but when you open up the boxes you will find that the roof mounts are sourced from a separate company. I recently installed an Iron Ridge racking system and was quite impressed, the quality was good and the hardware packing was spot on which is quite useful to avoid having to go dig in the hardware jar for missing hardware. I also liked that they have standardized fastener sizing somewhat so that the number of tools in the pouch was minimized. I had looked at Unirac and it appears to be good stuff but they mostly supply through large distributors in the New England area so the mark up was higher than Iron Ridge. Iron Ridges sizing program also dealt with my wind and snow loads better. They were also prompt at answering questions during the design phase. The only "nit" for iron ridge were the wire clips they supply, they are good for wire management when the cables run parallel with the racks but are useless when running vertically between racks.

Generally if specified and installed properly these systems work well. The weak spot is the installer, roofing labor tends to be paid for muscle not for brains and you are dependent on them to read the manual and properly install the mounts. If they just want to get finished and head off for beer, well your mounts could leak of fail. A good roofer can custom build a mount, generally by fabricating a flashing boot around a fastener attached to the understructure and possibly pouring it in but the problem is that this is not an engineered mount and lacks a PE stamp so the entire racking system may not be accepted by an inspector without a PE stamp on the plans.

The good thing is that the environment and exposure of roof mounts tend to be covered over the by the panels so they aren't as exposed to extreme weather.

I used a solar deck enclosure on my recent installation, I was quite impressed with the design and expect I wont be worrying about roof leaks, its a well thought out system where someone needs and integrated combiner box and roof enclosure, but not sure about microinverters as I haven't any experience with them. Its low profile compared to other alternatives I looked at.

[albert436]

Interesting thread.

Mr. Peakbagger, I googled solar deck enclosure and came up with SolaDeck Enclosure:

SOLAR PHOTOVOLTAIC
WIRING ENCLOSURES
Protect the roof and PV wiring with SolaDeck. Combine flashed roof penetration protection with the ability to transition, pass through, or combine solar PV strings with one of our weather tight enclosures. SolaDeck's state-of-the-art enclosure systems are simplifying roof-mounted combiner/enclosure installations.

Install solar PV wiring faster and easier with SolaDeck's simple design and clear instruction process. Choose SolaDeck, the most preferred PV enclosure by professional contractors, for a professional installation every time!

SolaDeck flashed photovoltaic roof-mount system:

Installs quickly, easily, and consistently every time
Protects solar panel wiring with a weather-proof flashed seal
Prevents roof damage with non-invasive installation

It is telling me what it does but I am having a little trouble picturing what it is and what it looks like. Is the installation somewhat idiot proof, ie. will it mitigate a situation where the installers are not the sharpest tools in the shed ?

Thanks !

[peakbagger]

Bring and old post back to life?. The Soladeck boxes are designed for asphalt shingle roofs, cut the shingles to fit the box and it slides up under the shingles. The panel wires come up through the bottom. There is a DIN rail with DIN fuse blocks or just plan terminal blocks. If you have multiple strings its the best place to combine the strings. The wiring from the combiner runs thorough the back of the box through the roof into the metallic conduit you run down through the house to the inverter.

Do note that the new version of the code requires a remote controlled disconnect to disconnect the panel wiring within a short distance of the panels. I am surprised that the maker of Soladeck hasn't designed and option to integrate this function into the box as its the logical spot for it

[albert436]

I think I get it, the wires drop down through the box then run under the roof in the attic space ?

Lol the real reason I pulled up this old thread was to check out JPMs post about his system install. Then I got interested in your discussion of mounts etc.

Edit and PS: Peakbagger are you a pro installer ? And isn't a peakbagger someone who tries to climb all the notable mountain peaks he can ? A colleague was just regaling me this morning about his ascent of Ranier two weeks ago, it didn't sound like much fun to me !

[peakbagger]

Yup, the bottom plate has few punch outs. Just drill a hole up through the roof sheathing and slide a thread bushing up through the plate and then continue the conduit down to the basement. (you cant just run wires, you have to have an approved metallic conduit all the way to an accessible disconnect).

I am not a professional installer I just keep my hands dirty on occasion. I do small power plants for a living.

I used the same screen name for a few hobbies. I live in northern NH in the whites and am hiking most weekends.

[peakbagger]

Yup, the bottom plate has few punch outs. Just drill a hole up through the roof sheathing and slide a thread bushing up through the plate and then continue the conduit down to the basement. (you cant just run wires, you have to have an approved metallic conduit all the way to an accessible disconnect).

I am not a professional installer I just keep my hands dirty on occasion. I do small power plants for a living.

I used the same screen name for a few hobbies. I live in northern NH in the White Mountains and am hiking most weekends.