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  • #16
    Originally posted by J.P.M. View Post

    1.) On rafter location: If you can see the rafter from the interior, this doesn't matter., but sometimes, or more often, a rafter is not one continuous piece. If so, and thus overlapped/staggered, that will knock the rafter C.L. by one width left or right from the under-eve rafter location.
    No, my rafters are generally continuous and not overlapped or staggered. There is some sub-structure framing that causes a substantial change in rafter pattern in a couple of spots. I can post some pictures for those interested.

    Originally posted by J.P.M. View Post
    2.) On your point one, that's a pretty standard way to do tile fixation with the use of roof cement /etc. over the nail holes and then the sealed nail hole covered by the tile above. As long as the tile above is intact, it's OK.
    Nope, no roofer's cement or other sealant on these nails. 100% of protection for these penetrations is provided by the tile layer above.

    Originally posted by J.P.M. View Post
    Also, and pardon me if this sounds condescending, but, in case you don't know, the way to walk on flat concrete tiles and (hopefully) minimizing breakage is to step on a tile so that the C.L. of your foot is parallel to the bottom edge of the tile as much as possible, while staying away from the tile edges as much as possible. Some dog ears and a break or two will likely happen anyway.

    NEVER step on the center of a tile. Stay away from the edges as well. Sounds like a PITA, but you'll get the hang and the habit of it after a trip or two to the roof, if you haven't got it already.
    I was cautious my first few trips up a month or two ago to take measurements for the permit application, using the techniques you've described here, but at this point I just walk freely (but not stupidly). I keep looking for a crack, but the next one I make will be the first one.

    Originally posted by J.P.M. View Post
    3.) Tiles are the initial water barrier, but the paper underneath is the primary protection from condensation, bugs, and other infiltration.
    I think my roof will be a good test for how long it takes for that condensation to do damage here. Thousands of holes protected only by the nail filling them. Clearly, the roof is better protected with paper than without (I'm not questioning that at all). It is just that it is hard to look at all those tile nails and think of the roof as having been impervious until I came along with my lag screws and PV mounts.

    Originally posted by J.P.M. View Post
    4.) On your point 4, and as a general rule of thumb, if you can see a penetration - a nail, bolt , staple, etc., water that was airborne from above can get at it. If an exposed penetration gets sealed, but not covered, it'll leak someday. If the flashing penetrations are raised so that all gaps are above any possible standing or flowing water level, and covered by tile as well as sealed/caulked, you're probably OK.
    No holes are visible when the concrete tiles are installed. With the tile removed, I bibbed with paper over the few new nails I put in when I was first following the instructions after step 5, but I have stopped putting in new nail holes to avoid this problem completely. Their function isn't so clear... there is nowhere for the aluminum flashing to go, even if the sealant that adheres it to the paper eventually lets go. Maybe the nails are needed for a steeper roof with more clearance between the deck and the tile? Here is the pic from the manual that shows them. nails.JPG






    Originally posted by J.P.M. View Post
    5.) On your point 6, They're tight now, but if there's any chance that the joint can come loose/rock itself out from thermal cycling or cyclic wind loads because of the absence of the (snapped) head, that may be a future problem. A blinding flash of the obvious: They shouldn't be snapping off. If the snapped part was part of what ensured continuing joint integrity, I'd be concerned.
    It is a weird use of screws... the screwhead isn't the functional end... the tip is. The quickhook mates with the mounting base like a slide and gib. The screw works sort of like a set screw in that once you drive the screw in far enough, the tip pushes on the base and forces the hook up against the gib, securing it. In other words, if the head were tightened against its mating face like a normal fastener, the screw wouldn't be doing anything at all (for that matter, the mating face in this case isn't even flat). A screw that is twice as long would be just as functional (but would interfere with the flashing). The picture from the instructions below, hopefully I'm describing this clearly enough. I'm sure they aren't supposed to shear, and the instructions warn against using an impact gun, but I'd rather have them too tight than not tight enough, you know? Medium torque on my drill doesn't drive them at all. screw.JPG








    From a common sense perspective, the concrete tile nail holes worry me much more than what I'm doing with these mounts, but I don't think I'm going to lose sleep over any of it. I'll definitely post some more pictures soon, but I understand better now why Solarix has taken the position he has on the suitability of some of Quickmount PV's competitors.

    Edit: In any case, J.P.M., thanks for the comments.
    Last edited by sensij; 04-24-2017, 05:48 PM.
    CS6P-260P/SE3000 - http://tiny.cc/ed5ozx

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    • #17
      Originally posted by sensij View Post

      No, my rafters are generally continuous and not overlapped or staggered. There is some sub-structure framing that causes a substantial change in rafter pattern in a couple of spots. I can post some pictures for those interested.



      Nope, no roofer's cement or other sealant on these nails. 100% of protection for these penetrations is provided by the tile layer above.



      I was cautious my first few trips up a month or two ago to take measurements for the permit application, using the techniques you've described here, but at this point I just walk freely (but not stupidly). I keep looking for a crack, but the next one I make will be the first one.



      I think my roof will be a good test for how long it takes for that condensation to do damage here. Thousands of holes protected only by the nail filling them. Clearly, the roof is better protected with paper than without (I'm not questioning that at all). It is just that it is hard to look at all those tile nails and think of the roof as having been impervious until I came along with my lag screws and PV mounts.



      No holes are visible when the concrete tiles are installed. With the tile removed, I bibbed with paper over the few new nails I put in when I was first following the instructions after step 5, but I have stopped putting in new nail holes to avoid this problem completely. Their function isn't so clear... there is nowhere for the aluminum flashing to go, even if the sealant that adheres it to the paper eventually lets go. Maybe the nails are needed for a steeper roof with more clearance between the deck and the tile? Here is the pic from the manual that shows them. nails.JPG









      It is a weird use of screws... the screwhead isn't the functional end... the tip is. The quickhook mates with the mounting base like a slide and gib. The screw works sort of like a set screw in that once you drive the screw in far enough, the tip pushes on the base and forces the hook up against the gib, securing it. In other words, if the head were tightened against its mating face like a normal fastener, the screw wouldn't be doing anything at all (for that matter, the mating face in this case isn't even flat). A screw that is twice as long would be just as functional (but would interfere with the flashing). The picture from the instructions below, hopefully I'm describing this clearly enough. I'm sure they aren't supposed to shear, and the instructions warn against using an impact gun, but I'd rather have them too tight than not tight enough, you know? Medium torque on my drill doesn't drive them at all. screw.JPG









      From a common sense perspective, the concrete tile nail holes worry me much more than what I'm doing with these mounts, but I don't think I'm going to lose sleep over any of it. I'll definitely post some more pictures soon, but I understand better now why Solarix has taken the position he has on the suitability of some of Quickmount PV's competitors.

      Edit: In any case, J.P.M., thanks for the comments.
      You're welcome. I reviewed the instruct. & video. Looking at them again later, that set screw arrangement seems a bit funky to me in that it might loosen up over time/temp. excursions and from wind vibration with not much, if any access or easy inspection. I guess I would have done those by hand and found some way to rig a (removable ?) locking nut/etc, on that set screw as wobbly insurance.

      I'd also figure out a way to slide a piece of AL that's wider than the AL flashing and slide it under the paper layer above, overlapping the nail holes in the flashing cover and secure the added AL piece w/ roof cement/adhesive. Reason: Looks to me that the upper horizontal edge of the flashing can be a leak point if left as fig. 5 shows and water somehow gets under the tiles above.

      On the nail holes for paper and for tile: When I had my roof serviced before array install, I used 2/3 overlapping layers of paper w/ the top layer covering the lower nail holes except for the uppermost layer at the peak, and all the nail holes in the paper supplied w/plastic collars and roof cement on top of and around the collars. Then, I had the tile nail holes/heads caulked w/silicon.

      FWIW, it's been my experience that if I haven't seen water damage/spots on the inside of the roof, the existing stuff hasn't failed yet, and probably won't anytime soon.

      Thanx for the response.

      Add: Forgot to mention: Forget needed to spend much time looking for cracks. In all likelihood, if a tile fails from foot traffic, you'll know it in a millisecond or two from the noise and impact of the failure. Like glass, most concrete tiles have an abrupt yield curve. Plan and expect to break a tile or two.
      Last edited by J.P.M.; 04-25-2017, 10:57 AM. Reason: Added add.

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      • #18
        Here are a few more pictures of the hook installation. I've got 19 of 34 up so far, getting about 4 done per hour in the time I've been able to find to work on this. At this point I should probably include my electric bill each month in the total accounting of cost each month (on the assumption that paying someone would have resulted in a completed system by now). I'm trying to avoid hiring babysitters to get a more focused run at this, but we'll see.

        I picked up some replacement rooftiles listed for free on Craigslist, and have been swapping them in. They aren't a perfect color match, and seem somewhat degraded, but by putting them under the array, I can keep the good ones I pull out for use in other repairs. I've found one catastrophically cracked tile on another part of the roof, and a few that are chipped along the seam that I'll probably leave alone for now.

        Prying out the tile isn't pictured here. I prop up the tile to the left with a small prybar, then pop up the nail slightly by lifting the tile I want to remove. A cat's claw and some elbow grease are used to reach under the upslope tile and pull out the nail by the exposed head.

        Find and mark rafter with a stud finder, then drill the 7/32" pilot holes: PilotHoles.JPG




        After backfilling the hole with Geocell 2300 and mounting the hook. Note the twisted off screwhead. I've adjusted my technique to avoid it sometimes, but am not too worried about it. AttachedHook.JPG




        U-shaped bead of Geocel applied to the back of the flashing before installation. A layer of roofing paper is also applied to further protect the uphill edge, but I'm no longer using nails in the corners, or pulling up any more adjacent tiles than necessary to drill the holes. Flashed.JPG




        Bottom of the tile is ground open to give clearance for the hook. Tileaftergrinding.JPG




        And, finished. You can see the chalk lines I had used to ballpark the location of the rafter and the right row of tile to locate the rail. Finished.JPG

        Last edited by sensij; 05-01-2017, 02:25 PM.
        CS6P-260P/SE3000 - http://tiny.cc/ed5ozx

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        • #19
          05/01/17, 1436 hrs: thanx for the info.

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          • #20
            Haven't updated in a few weeks, so some more pictures are below. All attachments are done, rails are up, and I've got the conduit penetration in and flashed. I'm using a Wiley ACE-2P for the junction box (found reference to it in a thread a couple years ago, thank you Amy@altE , slightly more expensive than a generic junction box with waterproof connectors would have been, but not by much. The first three panels went up tonight, it will take another week or so to get the rest up. Still some more conduit work to do as well. I gave up on the SE7600H-US, and have a SE7600A-US coming instead.

            tile removal.png


            rails.png






            conduit base flashing.png

            conduit base flashing with paper.png

            conduit tile.png



            conduit finished.png
            CS6P-260P/SE3000 - http://tiny.cc/ed5ozx

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            • #21
              Thanx for the update. Break any tiles yet ?

              So far, so good, but how are you gonna' get under the array when your curiosity gets the better of you ??

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              • #22
                Originally posted by J.P.M. View Post
                Thanx for the update. Break any tiles yet ?

                I had picked up a stack of free tiles from someone on Craigslist, in anticipation of breaking a few. Those tiles aren't an exact color match, so I ground a bunch of them for clearance for the hooks and swapped them in as I was installing the attachments. No one will ever see the color difference under the array, and by saving the tiles I pulled out, I've got good replacements for more visible parts of the roof. Anyway, the tiles I swapped in are older, and seem more fragile. I've broken 3 of them so far. If the entire roof had been tiled with them, this would have been a very different experience.

                So far, so good, but how are you gonna' get under the array when your curiosity gets the better of you ??
                The bottom of the rails are 3.75" above the surface of the lower tile, and the rail itself is 3" tall, so I've got a good 5" or so clearance underneath when I'm coming at it from above. Hopefully enough room to slide in some surface mount temperature sensors at some point That said, this array is going to be a nightmare to service [S]if[/S] when the optimizers eventually fail. Of the 28 panels going up, 12 will be inaccessible except by removing another panel. Because it is close to the edge of the roof, the bottom row is only accessible from above, and I'm not sure I can even reach the lower clamping screw from above... they are all getting installed from the side as the row gets built out. I guess a longer handled ratchet would be needed. I can tweak optimizer position to maybe make a couple of them more accessible, but mostly, I'm just hoping for no infant mortality so it will be a long time before I have to deal with any of it.

                I had toyed with the idea of lowering the rail clearance near the lower edge of the roof to squeeze another degree or two of tilt out of it, but at this point, it is easier to just use a standard spacer block everywhere, and I want to get it done.
                Last edited by sensij; 05-24-2017, 01:53 PM.
                CS6P-260P/SE3000 - http://tiny.cc/ed5ozx

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                • #23
                  Conduit run from the roof to the garage is complete, with the wires pulled. I'll have the inverter up in the next day or two... a little bit unconventional in that it will be mounted with 8" clearance to the ceiling of the garage, above the built-in closets. As far as I can tell, as long as clearances are maintained there is no requirement that it be at ground level.

                  7 panels are up, no pictures of that yet. Getting the alignment tweaked just right so that a 16 panel line tracks straight across the roof took a couple of attempts, but I think at this point it will build out without too much more adjustment. Iron Ridge's UFO fasteners are rough to work with using only a ratchet and torque wrench, next time I'm up there I'll try using a socket on a drill with the clutch set low and see if that goes more smoothly.

                  Pictures of the DC conduit run are below.

                  attic - 1.JPG


                  attic - 2.JPG

                  attic - 3.JPG

                  attic - 4.JPG

                  garage - 1.JPG
                  CS6P-260P/SE3000 - http://tiny.cc/ed5ozx

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                  • #24
                    Thanx for the info.

                    I'm pretty sure I know the answer to this, but just to be sure: The inverter is wall mounted ? If so, is it a north wall ?

                    The 7600A-US inverter (yours, right ?) manual/spec sheet says it has an internal fan, but given the likely or possible garage roof temps., natural convection across the exterior fins may be impeded a bit if the interior roof temp. (or wall temp.) is warm and the clearance is minimum - the driving temp. differences will be less and slow down the bulk air velocity, reducing cooling capacity. Any clearance considerations for perhaps adding a fan under the fins if things get hot ? I sort of wonder if the 8" overhead spec. sheet min. top clearance is still good if/when mounting on/near warm(er) surfaces. Just a thought.

                    FWIW, I knock about 10 deg. C. out of the inverter operating temp. by using a fan and reduce the temp. diff. inverter operating temp. to garage amb. temp. from ~ 30 C. to ~ 20 C. under full load.

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                    • #25
                      The inverter is mounted to an interior wall of the garage. Below is a picture to help explain.

                      This is the front of the house, which is west facing. Half of the south wall of the garage is exposed on the exterior (but shadowed) at the front door entry, the other half makes up an interior wall leading in from the front door. The inverter is on that south wall, in deep in the garage where it forms the interior wall. Conduit will run across the ceiling of the garage and through the north wall, which is where the MSP is located.

                      The garage temperature is very moderate since it has very little south facing exposure, and this wall in particular is insulated and doesn't noticeably warm. The garage door can get warm once the sun gets far enough west, but it doesn't raise the temperature of the garage too much. The hardest room in the house to keep comfortable is the 2nd story, southwest corner... in the upper right of the picture.

                      All this to say, I think the min clearances have a chance at being sufficient. SolarEdge makes inverter temperature data available for monitoring, so I can see if it ends up warming more than I am expecting. Adding a fan should be feasible if needed... the wall insulation would probably do a good job of muffling any sound that might carry through into that hallway.

                      (BTW.... not my car... this picture was before we moved in last year, I guess)

                      street view.JPG
                      CS6P-260P/SE3000 - http://tiny.cc/ed5ozx

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                      • #26
                        Thank you. If the gar. roof/interior ceiling temp. is elevated, that and the 8" clearance will change the nat. convection driving forces a bit. It'll probably be OK. Just some random thoughts that crossed my mind, and perhaps for the back of yours if inverter temps are higher than expected or as f(time of day).

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                        • #27
                          Got the inverter up last night. The ceiling in this area of the garage is the floor of a bedroom, with about 9" of mostly insulated space for the floor joists. Definitely not the ideal location for thermal management. Also not ideal for transmission loss, it is about 40 ft from the array junction box, and about 40 ft away from the MSP. I'd rather have more of the run on the DC side to minimize loss. It does meet the aesthetic requirements though, and supports my goal of no exterior conduit. I'm glad to get the feedback on potential issues to watch out for once it is in operation, and am really glad SolarEdge makes it easy to keep an eye on temperature.

                          It still needs a label and a strap within 3 ft of the termination. A strap over the kink in the conduit is a good spot, and will help hide that oops... I think I put the offset bend too close to the 90, and didn't successfully make both bends without the conduit giving out.

                          inverter.JPG

                          CS6P-260P/SE3000 - http://tiny.cc/ed5ozx

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                          • #28
                            The conduit bend reminds me of when I practiced with our electrical dept hand bender. Mine was much less pretty then yours.

                            Besides the heat build up above it, the only other thing I see as a disadvantage is that you will need to work off a ladder anytime you go into that inverter. You might consider some type of tie off so you don't hurt yourself if you fall.

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                            • #29
                              》>>> bit unconventional in that it will be mounted with 8" clearance to the ceiling of the garage, above the built-in closets. As far as I can tell, as long as clearances are maintained there is no requirement that it be at ground level.

                              Not that it means much, but my installer fought back with raising my inverter above 6 feet (the top above 6) saying it had to be "accessible" and the inspector would be a stickler so don't put anything in front of it or within 18 inches of each side of it. I wanted mine up high so i could put cabinets under it just like yours. Good luck.

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                              • #30
                                Originally posted by cebury View Post
                                》>>> bit unconventional in that it will be mounted with 8" clearance to the ceiling of the garage, above the built-in closets. As far as I can tell, as long as clearances are maintained there is no requirement that it be at ground level.

                                Not that it means much, but my installer fought back with raising my inverter above 6 feet (the top above 6) saying it had to be "accessible" and the inspector would be a stickler so don't put anything in front of it or within 18 inches of each side of it. I wanted mine up high so i could put cabinets under it just like yours. Good luck.
                                Yeah, I think 110.26 is the only specific code that applies, and what I've done could be interpreted as compliant, or non-compliant, depending on who is looking at it. There is nothing specifically against using a ladder for serviceability, we have transformers and other electrical equipment all over the place where I work that require a ladder to access. I think the important thing is that it is serviceable, and there is plenty of space here to open it up. I've seen plenty of examples locally with inverters (and even disconnects) on the roof, my bigger concern is whether reaching over the cabinet classifies this as inaccessible, even though in practice, I'd just sit on the cabinet to work on it.
                                CS6P-260P/SE3000 - http://tiny.cc/ed5ozx

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