Buried conduit sch 40 A section on the ground

solarhungrysolarhungry Registered Users Posts: 29 ✭✭
I have had some awesome advice and I have another question. I researched but didn't get a direct answer.
Currently I have my solar array wires, 2/0  in 1.25" sch 40 going to the equipment about 85'. For now till I know for sure everything is good,  it is on top of the ground  pieced together not glued.  Most of it will be buried at least 18". 
My question is I have a section under the 2' high porch that is about 15' of conduit. Can I leave this section above ground and be at NEC code? The porch is surrounded by lattice to keep things out. Thanks!

Comments

  • mcgivormcgivor Solar Expert Posts: 3,167 ✭✭✭✭✭
    Generally running PVC conduit outdoors is permitted, above grade and not subject to mechanical damage, if the conduit is not labeled direct burial only. Below is an anewer to a very similar question, please note my experience is ba sedan on Canadian.Electrical Code, always best to ask the authority having juristiction, electrical inspector, before proceeding, nothing worse than having to remove and redo.

    National Electrical Code 2014Article 352 - Rigid Polyvinyl Chloride Conduit: Type PVCII. Installation

    352.10 Uses Permitted. The use of PVC conduit shall be permitted in accordance with 352.10(A) through (H).

    (F) Exposed. PVC conduit shall be permitted for exposed work. PVC conduit used exposed in areas of physical damage shall be identified for the use.

    (G) Underground Installations. For underground installations, homogenous and nonhomogenous PVC shall be permitted for direct burial and underground encased in concrete. See 300.5 and 300.50.

    Article 300 - Wiring MethodsI. General Requirements

    300.5 Underground Installations.

    (D) Protection from Damage. Direct-buried conductors and cables shall be protected from damage in accordance with 300.5(D)(1) through (D)(4).

    (4) Enclosure or Raceway Damage. Where the enclosure or raceway is subject to physical damage, the conductors shall be installed in rigid metal conduit, intermediate metal conduit, Schedule 80 PVC conduit, or equivalent.

    352.10(F) says that the PVC conduit "used exposed in areas of physical damage shall be identified for the use". I know schedule 80 is suitable for protection from physical damage, however, the Authority having jurisdiction in your area may allow schedule 40 as well. You'll want to check with your local inspector to be sure, or use schedule 80 for the exposed section.

    300.5(D)(4) says that even though the conduit is buried, if it's subject to physical damage (not deep enough, under a garden, etc.) it still has to be schedule 80.

    UL 651Schedule 40, 80, Type EB and A Rigid PVC Conduit and Fittings

    1.2 Schedule 40 and 80 conduit and fittings

    1.2.1 Schedule 40 rigid PVC conduit and fittings are for aboveground use indoors or outdoors exposed to sunlight and weather, and for underground use by direct burial or encasement in concrete. Schedule 40 rigid PVC conduit, elbows, that are specifically marked for underground use are suitable for use underground only by direct burial or encasement in concrete.

    The UL listing says both 80 and 40 can be used in both above and underground installations.

    Guide Information for Electrical Equipment The White Book 2013Rigid Nonmetallic PVC Conduit (DZYR)Use and Installation

    Schedule 40 conduit is suitable for underground use by direct burial or encasement in concrete. Schedule 40 conduit marked "Directional Boring""(or "Dir. Boring") is suitable for underground directional boring applications. Schedule 40 conduit is also suitable for aboveground use indoors or outdoors exposed to sunlight and weather where not subject to physical damage. Schedule 40 conduit marked "Underground Use Only" is only suitable for underground applications.

    Schedule 80 conduit has a reduced cross-sectional area available for wiring space and is suitable for use wherever Schedule 40 conduit may be used. The marking "Schedule 80 PVC" identifies conduit suitable for use where exposed to physical damage and for installation on poles in accordance with the NEC.

    The White Book clearly states that only schedule 80 is suitable for use where exposed to physical damage, though again, says schedule 40 is suitable for aboveground use (unless labeled otherwise). So while you may be able to use schedule 40 for the entire run, you'll have to use schedule 80 through any areas where the AHJ deems the conduit is exposed to physical damage.

    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery bank 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah FLA 24V nominal used for water pumping and day time air conditioning.  
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  • solarhungrysolarhungry Registered Users Posts: 29 ✭✭
    edited July 2017 #3
    @mcgivor,
    Thanks for sharing that. My city doesn't require permits for solar at this time but with solar growing fast in the next city over that might change fast. I still want to try and make it to code.  Do you know if the NEC over powers the city? Part of the word  National in NEC tells me it might.
  • mcgivormcgivor Solar Expert Posts: 3,167 ✭✭✭✭✭
    edited July 2017 #4
    Think of the NEC as a book of rules and guidelines, which are open to interpretation, to some degree, the electrical inspection department, usually a branch of local government, is the authority having juristiction and use the NEC as a common resource used by all inspectors nationally. Following the guidelines is probably the best you can do in the absence of permit requirement, however asking a local electrical inspector to clarify your interpretation of the rules, is in my opinion, a good idea, as some of the code rules can be confusing to those not familiar with the trade in general.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery bank 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah FLA 24V nominal used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • SolraySolray Registered Users Posts: 246 ✭✭✭
    > @solarhungry said:
    > @mcgivor,
    > Thanks for sharing that. My city doesn't require permits for solar at this time but with solar growing fast in the next city over that might change fast. I still want to try and make it to code.  Do you know if the NEC over powers the city? Part of the word  National in NEC tells me it might.

    No. Your local municipal codes are what you must comply with.
  • EstragonEstragon Registered Users Posts: 4,202 ✭✭✭✭✭
    In Canada at least, it IS the local application/interpretation of code that governs. Generally speaking, the national code is extended to address locally important issues, for example, increased minimum insulation in extreme climates.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • SolraySolray Registered Users Posts: 246 ✭✭✭
    In the US it's the counties that set the regulations and cities sometimes add to those codes due to differing circumstances and local conditions.
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