My first install, questions thread.

five.five-six

Senior Member
Location
california
Starting my first install presently, I started slow. Red some books, took some classes, opened an account with CED/greentech, and started an account with an engendering firm that draws up plans that seem to sail through plancheck.

My first job is on my own house... didn’t want to put any customer through any trial and error.


System will be 26 Hyundai mono crystalline 290W modules, solar edge optimizers and a solar edge SE6000H

Racking is Iron ridge XR10 and I’m doing supports on 48”

* Here is my first question, how far apart do I need to space the rales apart. I didn’t find any specification. It seems like there is a lot of leeway so long as the modules land on the rails on the outer 12” or so.

* 2nd question, and I think I know this... PV wire on the roof to the JB or combiner box and then #10THHN back to the inverter in a metal raceway marked with PV stickers and nothing else in it except the EGC? Is that right?
 
Last edited:

electro7

Senior Member
Location
CA, US
* Here is my first question, how far apart do I need to space the rales apart. I didn’t find any specification. It seems like there is a lot of leeway so long as the modules land on the rails on the outer 12” or so.
Yes, 12" is a good rule of thumb. If you want to get specific you can check the module manufacturer installation guides. They usually show the parameters of what range the panels can be supported at.

* 2nd question, and I think I know this... PV wire on the roof to the JB or combiner box and then #10THHN back to the inverter in a metal raceway marked with PV stickers and nothing else in it except the EGC? Is that right?
Correct. #10 is good.

Sent from my Pixel using Tapatalk
 

jaggedben

Senior Member
Consult the module installation instructions for the maximum distance of the rail from the end of the module. I've generally found that if you are within the first 25% of the module length from the end, you're okay. 12" on a 60cell module has always been fine as far as I've seen.
 
What exactly is the j box/ combiner you refer to? Seems like the inverter would have a few mppt's so no need for a combiner. Does it have rapid shut down capability? Remember too, you can run pv wire right into the inverter if you want, no need to necessarily transition to thhn.
 

five.five-six

Senior Member
Location
california
Sure but it’s going to be at least a 60 foot probably 80 foot run from the roof to the inverter. PV wire is expensive and I have tons of number 10 THHN. My understanding is the rapid shut down functionality is built into the optimizers
What exactly is the j box/ combiner you refer to? Seems like the inverter would have a few mppt's so no need for a combiner. Does it have rapid shut down capability? Remember too, you can run pv wire right into the inverter if you want, no need to necessarily transition to thhn.
 

jaggedben

Senior Member
How do you make the DC safe to work on.?

I read you can open the string, short each module or cover each module with an opaque material.
I thought you were using optimizers? The brands I'm aware of keep the voltage safe until you turn the system on.

If you're not using optimizers, then...


- You wire up everything other than the panels before you plug them into anything but each other.
- You disconnect the load (turn off inverter) before unplugging anything.
- You understand that this still doesn't necessarily make it safe.
 

five.five-six

Senior Member
Location
california
I thought you were using optimizers? The brands I'm aware of keep the voltage safe until you turn the system on.

If you're not using optimizers, then...


- You wire up everything other than the panels before you plug them into anything but each other.
- You disconnect the load (turn off inverter) before unplugging anything.
- You understand that this still doesn't necessarily make it safe.
Yes, that makes sense :)

Now, I have worked while on a roof many many times but this my first time working on a roof.

From these photos, is there anything obvious that I'm doing wrong? (besides dripping mastic everywhere, I picked up on that all by myself)


Tile roofs are a lot of work.






 

jaggedben

Senior Member
Well...

Your work looks okay :thumbsup: but I can't believe your tiles aren't on wood battens. :blink: Whoever installed your roof originally was seriously cutting corners. I don't think what you've done will actually make things any worse than before. But if one of our crews encountered something like that I would probably ask them to stop work while I discussed with the homeowner that they either get their roof redone or that we don't accept liability for leaks on a roof that wasn't properly built to begin with.

I guess this is your own home so no one will sue you if anything happens.;)
 

five.five-six

Senior Member
Location
california
Well...

Your work looks okay :thumbsup: but I can't believe your tiles aren't on wood battens. :blink: Whoever installed your roof originally was seriously cutting corners. I don't think what you've done will actually make things any worse than before. But if one of our crews encountered something like that I would probably ask them to stop work while I discussed with the homeowner that they either get their roof redone or that we don't accept liability for leaks on a roof that wasn't properly built to begin with.

I guess this is your own home so no one will sue you if anything happens.;)
I had thought the buttons were supposed to be every other rank and they were to keep the tiles from slipping off the roof. The roof is 5.5:12 and they nailed every rank. I nailed every rank I removed except the top rank which I used a dab of adhesive to hold to the tile above it.


I was also very concerned at one point that the roof felt really spongy for a residential roof but it turned out we were just having an earthquake at that moment.
 
Sure but it’s going to be at least a 60 foot probably 80 foot run from the roof to the inverter. PV wire is expensive and I have tons of number 10 THHN. My understanding is the rapid shut down functionality is built into the optimizers

Fair enough. It's maybe a $40 difference for your system, but if you have "free" thhn already, then certainly more. Although time and extra parts could chew thru that $40. On the other hand, PV wire is larger possibly requiring a larger pipe and not as super happy fun time to pull......

You are going to love your system. I look at my output everytime I go down to the solar shed.
 

five.five-six

Senior Member
Location
california
Fair enough. It's maybe a $40 difference for your system, but if you have "free" thhn already, then certainly more. Although time and extra parts could chew thru that $40. On the other hand, PV wire is larger possibly requiring a larger pipe and not as super happy fun time to pull......

You are going to love your system. I look at my output everytime I go down to the solar shed.

Not exactly free but last time I went to the scrap yard, there was a Berg electric apprentice in a Nisan Sentra using a hacksall to cut the ends off about 50 new spools of #10 he was told to scrap. I bought 10 rolls off him for $100 and he got out of taking them off the spool.



So, how are you guys that do tile notching the tiles? I picked up a m18 angle grinder and put a diamond blade on it. It works better than an abrasive disk but there has to be a better way.
 

jaggedben

Senior Member
So, how are you guys that do tile notching the tiles? I picked up a m18 angle grinder and put a diamond blade on it. It works better than an abrasive disk but there has to be a better way.
There's not really a better way. Turbo blade works better than a straight cutter. You might look at the the Ironridge tile replacement flashing, I've given them some thought but they're much more expensive than the hooks I'm using.
 

five.five-six

Senior Member
Location
california
There's not really a better way. Turbo blade works better than a straight cutter. You might look at the the Ironridge tile replacement flashing, I've given them some thought but they're much more expensive than the hooks I'm using.

yes, I think they are about $12 each from greentech so, depending on how much time they save it may be worth it. Quick hook has a free samples form on their webpage, I ordered about one of each. I’ll post if I like them.

The diamond blade I have been using has been on my die grinder for about 7 years, which is about when I lost the removal tool LOL. I’ve done a bunch of semiflush resi stucco service change outs with it. It’s seen better days. I picked up a Makita blade from HD because it seemed to have the widest diamond embedded section of all their offerings. I end up using it more like a disk sander than a cutting wheel.
 

Whalepod

Member
Location
CA
Not exactly free but last time I went to the scrap yard, there was a Berg electric apprentice in a Nisan Sentra using a hacksall to cut the ends off about 50 new spools of #10 he was told to scrap. I bought 10 rolls off him for $100 and he got out of taking them off the spool.



So, how are you guys that do tile notching the tiles? I picked up a m18 angle grinder and put a diamond blade on it. It works better than an abrasive disk but there has to be a better way.
My preferred method is a hammer. With proper technique you can usually remove enough material by channeling your inner stone mason, with practice wont break tile, and it's pretty fast/light on the roof... this avoids the recreation of the ashes scene from the Big Lebowski, and controls silica dust much more effectively than a grinder. The grinder is great for precision and would be my preferred method in a perfect world, but if your doing this on a regular basis anything short of spraying water to control dust is going to put your guys in a Silica dust situation you may not want OSHA privy too. Hammer isn't perfect, but I feel better about asking my staff to do it than grinding. Being in Norcal and working in a specific demographic we work on the same tile homes all the time, and are picky about the projects we take on, so if your in the for profit world obviously your mileage may vary if your seeing a bunch of different types of tile.

We are making the switch full time to tile replacements. Honestly I hate them... I've used Quickmount's replacements and they're flimsy garbage. Our program works with lots of volunteers, and it's damn near impossible from keeping an inexperienced person from stepping on them, or any tile they're adjacent too and bending them all up. SnapNRacks tile replacements have so far been vaporware. I've heard mixed reviews of Pegasus, but it's another possibility I guess. I've never used iron ridge, but I imagine they're pretty similar to the others. It's just not much fun hauling 300+lbs of tile off a 2 story roof when it's 120+ up there. Most of our homeowners don't want 20+ replacement tiles, and it's not like I can just throw them in the garbage dumpster at work. 20 tile thrown in here and there isn't a huge deal, but if I'm building 5-6 jobs a week that adds up to a lot of concrete disposed improperly.

No solution is perfect that I've seen. I'm definitely up for suggestions though!
 
Last edited:

jaggedben

Senior Member
@Whalepod

Ironridge's approach doesn't require precise vertical location of the post, which I think would be a major advantage for saving time and avoiding mistakes and frustration.

Thanks for the comments about customers. I was figuring that ending up with spare tile would be an advantage (i.e. if you break any you don't have to go to the boneyard). But I wasn't considering the flip-side. Probably depends on the job which is better on that score.
 

five.five-six

Senior Member
Location
california
@Whalepod

Ironridge's approach doesn't require precise vertical location of the post, which I think would be a major advantage for saving time and avoiding mistakes and frustration.

Thanks for the comments about customers. I was figuring that ending up with spare tile would be an advantage (i.e. if you break any you don't have to go to the boneyard). But I wasn't considering the flip-side. Probably depends on the job which is better on that score.

I’d think most customers would be thrilled to have a bunch of spare tiles at the end of the job with matching patina.
 

five.five-six

Senior Member
Location
california
Forgot to mention this

Forgot to mention this

First day:
I had about 20 or so tiles off and was laying out the rail supports and penetrations when all of a sudden I thought: “Gee, this section of the roof is awfully spongey. I’ve worked on spongey roofs before, most tilt ups are varying degrees of spongey but residential are most always rather rigid”

And then a minute later, it wasn’t spongey anymore, nice and firm like I expected


And then about an hour later, another portion of the roof felt spongey .... but just for about a minute and then it was firm again.

Really strange.

_________________
 
Top