Looking for Suggestions for Wire Management on the Roof

Got one last mini-subject to ask for help, please (will then be ready for a status update).

What is commonly used in the field for wire management. I'm referring to managing each panel's USE-2 wires, coming out each panel's junction box, that connect the panels together in a daisy-chain fashion.

I know the answer is not zip ties, regardless of how much the zip tie manufacturer advertises them as UV 'resistant.'

My guess is it's something made of stainless steel.

What really works well, to permanently forever keep the USE-2 wires from laying / rubbing on the asphalt roof shingles, that won't ever require periodic replacement?

Many thanks!

Best regards,

Bill

Comments

  • Solar GuppySolar Guppy Solar Expert Posts: 1,989 ✭✭✭
    Re: Looking for Suggestions for Wire Management on the Roof

    Ziptie are fine, they are not in the sun. Also, I'm not aware of any issues with USE2 making contact on the roof. I use the ones that have the screw hole on the zip tie, shoot that into the panel and then the wire is only in contact with the ziptie, not sandwiched to the panel frame

    So zip it and if for some reason it fails, who cares, unless you specifically looking under the panel you can't see it. My installation have been inspected and approved so this isn't just some DYI tip
  • a0128958a0128958 Solar Expert Posts: 316 ✭✭✭
    Re: Looking for Suggestions for Wire Management on the Roof

    SG, thanks for the feedback / instruction.

    The challenge for this subject is the local municipality. They have a few requirements that they're insisting on, one of which deals with cable ties:

    "6. Cable ties shall not be used to secure exposed wiring between modules (panels). Approved clips, stainless steel cable ties, or stainless steel pipe clamps with rubber inserts are acceptable."

    Thus, I'm looking for examples of what can be used for "approved ..." as noted above.

    Thanks,

    Bill
  • Solar GuppySolar Guppy Solar Expert Posts: 1,989 ✭✭✭
    Re: Looking for Suggestions for Wire Management on the Roof

    Do this local regulation also state the USE2 can not touch the roof?

    I understand the issue of locally imposed rules. With your racking system it would be simple to just coil the excess and stuff between the railing and panel ... again nothing in the code to prevent this
  • a0128958a0128958 Solar Expert Posts: 316 ✭✭✭
    Re: Looking for Suggestions for Wire Management on the Roof
    Do this local regulation also state the USE2 can not touch the roof?

    No, but, I believe that is the intent of what is stated in item number 6, as I wrote above.

    I also found a John Wiles' Code Corner article, from Home Power 128 / Dec. 2008 & Jan. 2009, titled "Roof-Mounted PV System Design Challenges." It says, in part:

    "... the excess lengths of conductors must be securely fastened against the module racks to resist abrasive damage due to wind, sleet, and ice (my comment: we have all three). Many installers use plastic cable ties, but unless they are of very high quality, they may not last the required 40 years or more when exposed to the heat and UV radiation from sunlight. Some system integrators use a stainless-steel pipe clamp (a.k.a loop strap) with an EDPM insert."

    There's also a picture of the stainless steel loop strap in the article.

    Thanks.

    Best regards,

    Bill
  • newenergynewenergy Solar Expert Posts: 291 ✭✭✭✭✭✭
    Re: Looking for Suggestions for Wire Management on the Roof

    Zip ties.

    One of the few things inspectors actually check for is that wires don't hit the roof. A system will almost never pass inspection around here if they do. Also, it's a bad idea for them to touch the roof. I've noticed other wires that have been touching the roof for a long time and the insulation does wear off.

    I've used the metal clips that clip onto the modules and hold the wires, but I don't like them so much anymore. They don't hold the wires that well and they have sharpish corners and are well grounded onto the modules the way they scratch the surface. I think it's a pretty fair ground fault risk.

    Some racking systems like prosolar have a channel that handles a lot of the wire management.

    I think there could be a better solution - maybe a UV resistant plastic that has a hole for a tech screw and clamped the wires a bit like one of those pieces for holding romex.
  • dwhdwh Solar Expert Posts: 1,341 ✭✭✭
  • System2System2 Posts: 6,290 admin
    Re: Looking for Suggestions for Wire Management on the Roof
    Ziptie are fine, they are not in the sun. Also, I'm not aware of any issues with USE2 making contact on the roof.

    So zip it and if for some reason it fails, who cares, unless you specifically looking under the panel you can't see it. My installation have been inspected and approved so this isn't just some DYI tip

    First time poster here. Usually just read, but had to comment on this one.

    I have to say that I find this comment really surprising (especially from an R&D guy).

    As a firefighter, and someone with a long PV history, one of the areas the industry really NEEDS to be careful of is workmanship. Anyone who thinks it's OK for PV wire to lay on top of an asphalt roof and rub with the wind for 20 + years, (or let rodents get to it, is asking for a fire, or an electrocution (or both). While zip ties may not be in the sun, will you bet your next paycheck that they will hold up for 20-30 years? As long as we are conducting up to 600vdc, there MUST be a higher standard of practice when it comes to wire management.

    And, if the current Standard of Practice accepts "... unless you specifically looking under the panel you can't see it" as being OK, then may I suggest another line of work.

    I don't mean to bash anyone individually, this is just a wake-up call to make sure PV retains a good reputation.

    Happy Holidays to all.....
  • a0128958a0128958 Solar Expert Posts: 316 ✭✭✭
    Re: Looking for Suggestions for Wire Management on the Roof
    newenergy wrote: »
    ... One of the few things inspectors actually check for is that wires don't hit the roof. A system will almost never pass inspection around here if they do.
    dwh wrote: »

    Yep, my municipality has made it very clear, zip ties are out, regardless of how rational the ordinance is or not.

    Thanks for the pointer to stainless steel zip ties, or the clamps. Both are examples of what I've been looking for. Definitely much appreciated!

    Best regards,

    Bill
  • System2System2 Posts: 6,290 admin
    Re: Looking for Suggestions for Wire Management on the Roof

    Look up "Adel clamp". They are used in aviation for securing wires and are metal clamps with a rubber insert and have a single hole tab for a screw/bolt.

    Jamie
  • a0128958a0128958 Solar Expert Posts: 316 ✭✭✭
    Re: Looking for Suggestions for Wire Management on the Roof
    buz914 wrote: »
    Look up "Adel clamp". They are used in aviation for securing wires and are metal clamps with a rubber insert and have a single hole tab for a screw/bolt.

    Jamie

    Jamie, much appreciated. These are as the City inspector was describing, this past week, that I hadn't found any source for.

    Best regards,

    Bill
  • System2System2 Posts: 6,290 admin
    Re: Looking for Suggestions for Wire Management on the Roof

    Bill,

    Here is a good source for these clamps.

    http://www.aircraftspruce.com/catalog/appages/ms21919clamps.php

    Good Luck!

    Jamie
  • a0128958a0128958 Solar Expert Posts: 316 ✭✭✭
    Re: Looking for Suggestions for Wire Management on the Roof

    Jamie, thanks! (You must be a pilot or employed in the aviation industry!)

    Best regards,

    Bill
  • newenergynewenergy Solar Expert Posts: 291 ✭✭✭✭✭✭
    Re: Looking for Suggestions for Wire Management on the Roof

    I really don't like the stainless steel ties. It seems like a definite short hazard. The airplane things don't look bad, but they aren't meant to be outdoors are they?

    Does have any actual info on the useful life of nylon ties?
  • dwhdwh Solar Expert Posts: 1,341 ✭✭✭
    Re: Looking for Suggestions for Wire Management on the Roof
    buz914 wrote: »
    Look up "Adel clamp". They are used in aviation for securing wires and are metal clamps with a rubber insert and have a single hole tab for a screw/bolt.

    Jamie

    Yea, those are great for vehicular use. My only gripe is to wonder how long the rubber will hold up out in the elements for decades.
  • System2System2 Posts: 6,290 admin
    Re: Looking for Suggestions for Wire Management on the Roof

    The Adel clamps are usually used inside of airframes that are protected from the sun. They are also used inside engine compartments to hold fuel lines, ect. and are exposed to heat and lots of dirty air.

    I would say they are well suited for the job, especially if mounted under the panels away from direct sunlight.

    I personally used good quality "T&B" black UV ties with the little stainless tab in them for my system.

    As with any long term project, it requires maintenance. Very few things can be installed and expected to last 20+ years without some work on them.

    We also have to do what the inspector requires also!

    Jamie
  • BilljustBillBilljustBill Solar Expert Posts: 219 ✭✭✭
    Re: Looking for Suggestions for Wire Management on the Roof
    buz914 wrote: »
    Look up "Adel clamp". They are used in aviation for securing wires and are metal clamps with a rubber insert and have a single hole tab for a screw/bolt.

    Jamie

    Buz,

    After seeing your avatar and pictures of how you are mounting the panels, I wanted you to see a product that goes over R-panel and U-panel roofs.

    Here in North Central Texas, we had a major hail storm with 30 minutes of golf ball size hail. I have two outside buildings with those types of roofing panels, but they have insulation on the underside. In doing a lot of research, I found this company's product is little known about in these parts and is mainly in government and commerical work. The insurance company saw that using this product would not require tear-off cost, new insulation or replacement of a radiant barrier, and was to their advantage and approved it. It's called Roofhugger and is made in Florida to qualify for Dade County hurricane specs. It mounts directly over the existing roof and heavy screws go it and into the framework perlins in between the metal trusses. They seem to also provide a channel zone for mounting or hiding your wiring condiuts, too.

    http://www.roofhugger.com/ (link seems to be not working)

    http://www.dawnsolar.com/downloads/ECO-Fit%20web%20brochure.pdf

    Also using Kynar painted R-panels, each building has a cooler double roof with an air space between them that is vented with a ridge vent running the length of each building. The Roofhuggers not only make the span between the trusses stronger, but would seem better suited to holding solar panels or tilt framing on these types of roofs. My only concern would be about flat mounting and not allowing enough cooling underneath the PV panels....

    FYI,
    Bill
    Bill
  • System2System2 Posts: 6,290 admin
    Re: Looking for Suggestions for Wire Management on the Roof

    For solar wire-ways or wire management systems or Pv conduit...Check out (link edited by niel). Pv utopia is in the midst of manufacturing a few wire management systems that are easy to install, inexpensive and very clean aesthetically. You can check out our patent-pending products available to the market and in development on the website above. We welcome the opportunity to work with other Pv Manufacturers, Distributors, and Installers to supply custom solar wire management systems to any unique array designs, module frames or racking systems.
  • BB.BB. Super Moderators, Administrators Posts: 32,817 admin
    Re: Looking for Suggestions for Wire Management on the Roof

    PVU,

    Since many people here are DIY self installers... Do you sell retail or do you have a distribution network for your wire management products?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • System2System2 Posts: 6,290 admin
    Re: Looking for Suggestions for Wire Management on the Roof

    Thanks for your interest, Bill. Which model of our wire management system are you interested in? Some are available sooner rather than later. Although all of our products are patent pending, we are in the tooling process all across the board (hence the N.d.a. agreement on the site). I can say that we are expected to have product available in 2-3 weeks for shipment. You will be able to order directly from us using our website, and hopefully through a few distributors as well!

    Do you have a specific size module or manufacturer that you are using on your next job? We base our pricing per module or by the linear foot. If you would like to place an order, there will be a shopping cart on the site shortly, indicating that a certain PV wire management model is available to ship. Feel free to contact us at [email protected] with any other questions.

    Jason
  • BB.BB. Super Moderators, Administrators Posts: 32,817 admin
    Re: Looking for Suggestions for Wire Management on the Roof

    I was just asking in terms of the forum you have posted on... We are a mixed group and [the forum's charter] does not let people just drop commercial links here unless they can participate in the forum and/or offer useful information for the members here.

    I am not in the solar business, so I am not the one to ask.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • mike95490mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Re: Looking for Suggestions for Wire Management on the Roof

    popular problems have been wires between panels on a pole or ground mount array. Got gear for that ?
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • System2System2 Posts: 6,290 admin
    Re: Looking for Suggestions for Wire Management on the Roof

    Bill, Mike,

    I apologize, I accidentally missed the notification email from this blog a few months ago. Right now we are linking up to supply racking and module manufacturers directly. If you have a project that is in need of wire-management, please feel free to contact us. We will do our best to work with you. As for the gaps between pole mounts, the module mounted system should work just fine for pretty much any install... If you want a rack-mounted solution, send over some rack spec's and we will work to provide a custom solution. check out www.PVconduit.com for more details. Hope to hear from you,

    Jason Mazzone
    Product Development Manager
    [email protected]
    267-231-8963
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