1、Designation: E2766 13Standard Practice forInstallation of Roof Mounted Photovoltaic Arrays on Steep-Slope Roofs1This standard is issued under the fixed designation E2766; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of
2、last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice details minimum requirements for theinstallation of roof mounted photovoltaic arrays on steep-sloped roo
3、fs with water-shedding roof coverings. These re-quirements include proper water-shedding integration with theroof system, material properties, flashing of roof penetrations,and sufficient anchoring per regional design load requirements.1.1.1 This practice does not apply to building-integrated oradhe
4、sively attached photovoltaic systems that are applied asroof-covering components.1.2 This practice does not cover the electrical aspects ofinstallation.1.3 Installation considerations are divided into two distinctaspects: the interface between the photovoltaic module and thearray mounting structure,
5、 and the interface between the arraymounting structure and the roof or roof structure.1.4 Safety and hazard considerations unique to thisapplication, such as worker fall protection, electrical exposure,accessibility of modules, and roof clearance around the perim-eter of the array are addressed by o
6、ther codes, standards, orauthorities having jurisdiction.1.5 This practice is intended to provide recommendedinstallation practices for use by installers, specifiers,inspectors, or for specification by photovoltaic module manu-facturers.1.6 This practice provides minimum guidelines and shouldbe used
7、 in conjunction with module and mounting systemmanufacturers instructions. This practice offers a set of in-structions for performing one or more specific operations. Thisdocument cannot replace education or experience and shouldbe used in conjunction with professional judgment. Not allaspects of th
8、is practice may be applicable in all circumstances.ThisASTM Standard is not intended to represent or replace thestandard of care by which the adequacy of a given professionalservice must be judged, nor should this document be appliedwithout consideration of a projects many unique aspects. Theword “S
9、tandard” in the title means only that the document hasbeen approved through the ASTM consensus process.1.7 This practice is not intended to replace or supersede anyother applicable local codes, standards or Licensed DesignProfessional instructions for a given installation.1.8 This standard does not
10、purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. Specific hazards aregiven in Section 8.2.
11、 Referenced Documents2.1 ASTM Standards:2D1079 Terminology Relating to Roofing and WaterproofingD1761 Test Methods for Mechanical Fasteners in WoodE136 Test Method for Behavior of Materials in a VerticalTube Furnace at 750CE772 Terminology of Solar Energy Conversion2.2 AAMA Standards:3AAMA 800 Volun
12、tary Specifications and Test Methods forSealants2.3 ASCE Standards:4ASCE 7 Minimum Design Loads for Buildings and OtherStructures2.4 IEC Standards:5IEC 617301 (200410) Photovoltaic (PV) Module SafetyQualificationPart One: Requirements for Construction1This practice is under the jurisdiction of ASTM
13、Committee E44 on Solar,Geothermal and Other Alternative Energy Sources and is the direct responsibility ofSubcommittee E44.09 on Photovoltaic Electric Power Conversion.Current edition approved June 1, 2013. Published July 2013. DOI: 10.1520/E2766-132For referenced ASTM standards, visit the ASTM webs
14、ite, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from American Architectural Manufacturers Association (AAMA),1827 Walden Office Sq., Suite 550, Schau
15、mburg, IL 60173, http:/www.aamanet.org.4Available from American Society of Civil Engineers (ASCE), 1801 AlexanderBell Dr., Reston, VA 20191, http:/www.asce.org.5Available from International Electrotechnical Commission (IEC), 3, rue deVaremb, P.O. Box 131, CH-1211 Geneva 20, Switzerland, http:/www.ie
16、c.ch.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States12.5 UL Standards:6UL 1703 Standard for Flat-Plate Photovoltaic Modules andPanelsUL746C Polymeric MaterialsUse in Electrical EquipmentEvaluationsUL 609501 Table J.1 Electrotechnical
17、Potentials (V)2.6 Other Standards:IBC International Building Code7IEC International Electrical Code7IFC International Fire Code7NFPA 1 Fire Protection Code8NDS National Design Specification for Wood Construction93. Terminology3.1 Definitions: Definitions of terms used in this standardmay be found in
18、 Terminology D1079 and E772.3.1.1 steep-slope, adjin roofing, that which commonlydescribes an incline of a roof which is greater than 25 % (14or 3:12 vertical rise to horizontal run). D1079.3.2 Definitions of Terms Specific to This Standard:3.2.1 array mounting structure, n all structural and me-cha
19、nical materials used to support and anchor the photovoltaicmodules on the roof system between the attachment system andthe roof deck.3.2.2 attachment system, nall structural and mechanicalmaterials used to support and anchor the photovoltaic modulesto the array mounting structure.3.2.3 design life,
20、nthe period of time during which asystem component is expected to perform its intended function,without significant degradation of performance and withoutrequiring major maintenance or replacement. E7723.2.4 licensed design professional, LDP, nan individuallicensed to approve structural designs in t
21、he state or jurisdic-tion where the roof mounted photovoltaic array will beinstalled.3.2.5 representative section, none or more modules con-nected to an array mounting structure utilizing the sameconnecting devices as would be used in an installation.4. Significance and Use4.1 With the rapid growth
22、of the use of photovoltaic systemsin buildings, roof mounted arrays continue to be one of themost prevalent forms of installations. These roof mountedarrays typically feature penetrations into the roof system,which can result in water leakage issues if not properly flashedor applied to the roof syst
23、em.4.2 Structural integrity and durability of the application ofthe roof mounted array to the roof system must be adequate perapplicable codes and regulations. This applies to both thephotovoltaic module-to-array mounting structure interface andthe array mounting structure-to-roof interface.4.3 The
24、installation of roof mounted arrays presents certainhazards that must be addressed, which include fall protection,carrying loads up ladders, wind and rain exposure duringinstallation, and electrical exposure during connections.4.4 The topics covered in 4.1 through 4.3 are potentially asignificant ba
25、rrier to broad acceptance of roof mounted photo-voltaic systems if not adequately addressed.5. Material Requirements5.1 Design Life Alignment between the Array and theRoofIn many cases, the design life of the photovoltaic arraymay be significantly longer than the estimated design orremaining life of
26、 the roof covering. The condition of the roofstructure and surface shall be evaluated to determine whether itis sufficient to meet the design life of the roof mounted array.Consultation with a roofing professional and building owner isrecommended.5.2 Design Life (Exposure and Durability) of Array Mo
27、unt-ing StructureMaterials used in the array mounting structureshall be selected such that the expected design life of the arraymounting structure is no less than the design life of thephotovoltaic modules. Test data from similar exposure appli-cations is acceptable.5.2.1 Polymeric based materials u
28、sed in the array mountingstructure shall maintain structural integrity through expectedthermal exposure. Any polymeric materials in the structureshall have a relative thermal index (RTI), as defined in UL746C, of at least 90C. The thermal resistance of any polymericmaterial in direct contact with th
29、e module shall be specified bythe module manufacturer.5.3 Adhesive Sealant Requirements:5.3.1 Adhesives Used in Structural ElementsBondstrength must be sufficient to withstand structural loading asdetermined by 6.1 and be durable through the expected designlife of the array mounting structure. The s
30、tructural integrity ofthe bond joining the components of the mounting structure tothe array (or to each other) shall be verified through systemtesting per the structural requirements detailed in Section 6.5.3.2 Adhesives Used in Non-Structural BondingSealants(such as for glazings or other components
31、) must be verified tomeet the criteria for exterior perimeter sealants set forth inSection 808.3 of AAMA 800.5.4 Corrosion of Resistance of Metals:5.4.1 Dissimilar metals in direct contact may corrode. Useappropriate precautions per UL 60950-1 Table J.1 Electro-chemical Potentials (V).5.4.2 Requirem
32、ents for the array mounting structure shall bethe same as the corrosion requirements for the module as setforth in UL 1703 Sections 37 and 14 and Section 4.2 in IEC61730-1.5.5 Material CombustibilityWhere applicable by localjurisdiction fire code, materials used for the array mountingstructure to th
33、e roof shall be made of non-combustible materialper the requirements set forth in Test Method E136.Ifnot6Available from Underwriters Laboratories (UL), 2600 N.W. Lake Rd., Camas,WA 98607-8542, http:/.7Available from International Code Council (ICC), 500 New Jersey Ave., NW,6th Floor, Washington, DC
34、20001, http:/www.iccsafe.org.8Available from National Fire Protection Association (NFPA), 1 BatterymarchPark, Quincy, MA 02169-7471, http:/www.nfpa.org.9Available from the American Wood Council, http:/www.awc.orgE2766 132specified, the fire resistance of materials used in the arraymounting structure
35、 shall be reviewed by the LDP.6. Structural Requirements6.1 Design Considerations for the Installation of Photovol-taic Modules onto Array Mounting Structure:6.1.1 Manufacturers of array mounting structures shall pro-vide a pre-engineered, pre-tested system. The structure design,sizing method and at
36、tachment method shall be reviewed by anLDP or a representative section be tested for wind loadresistance.NOTE 1The mounting and fastening method shall comply with thearray mounting structure manufacturers recommendations subject toengineering requirements. If slots or multiple mounting holes are pro
37、videdon either the array mounting structure or the connections, the worst-casemounting positions shall be selected for testing purposes in order tosubject the array mounting structure to the maximum stresses.6.1.2 Design Load RequirementsThe module, the arraymounting structure, and the interface bet
38、ween the module andarray mounting structure shall be able to withstand regionaldesign loads as defined in applicable code, or calculatedaccording to ASCE 7 (whichever is more stringent), includinga minimum safety factor, such as from the Aluminum Asso-ciation design manual for Aluminum or AISC steel
39、 construc-tion manual for steel.6.1.3 The structural load of the attachment system shall notbe less than the design load requirements set forth in 6.1.2. Thestructural load bearing capacity of the attachment system of themodule to the array mounting structure shall be specified by themounting struct
40、ure manufacturer and be consistent with themodule manufacturers requirements.6.2 Design Considerations for the Installation of ArrayMounting Structure onto Roof StructureThe interface be-tween the mounting array and the roof shall meet the samestructural requirements as specified in 6.1. The roof st
41、ructureshall be evaluated by a LDP to assure that the roof structuralmembers are sufficient for added load of PV modules andmounting structures and the intended mounting does not createunacceptable point loads either due to snow, wind or seismic,or similar live loading.6.3 Anchoring for Regional Loa
42、d RequirementsAll fas-tening shall be into structural members of the roof. Themanufacturer of the array mounting structure shall reportrepresentative fastener installations pull out values into Hem-Fir (G=0.43) wood per the National Design Specification forWood Construction (NDS). Fasteners not cove
43、red by the NDSshall be tested per the requirements of Test Method D1761 andthe pullout values reported. For a given location, the uplift ordown load force may vary based on local wind, snow andseismic requirements, but the overall array mounting structureshall be designed to resist a minimum of 30 p
44、sf (146 kg/m2)uplift.6.3.1 For existing roofs, the installer shall inspect the roofstructure for suitability of attachment; the photovoltaic systemshall not be installed into damaged (soft spots, droops, unusualdiscoloration) structural material, such as decking material,rafters, or roof support, un
45、less approved by the LDP.6.4 Special Damage ConsiderationsBefore installation,consider the effects of extreme weather (hail, hurricanes, heavysnow), natural hazards (fire), and other potentially hazardousobjects (rocks, golf balls, insects, birds, chimney ash, sand,dust) on the performance of the ar
46、ray mounting structure.7. Integration with Existing Roof Systems7.1 Flashing Roof PenetrationsPenetrations into the roofshall be flashed in a manner that prevents moisture fromentering the roof system. Materials used to flash the fastenersand mounting device to the roof shall be sufficiently durable
47、and compatible with existing roof to maintain performancethrough the design life of the installation.7.1.1 The integration of the mounting system shall becompatible and aligned with the water shedding principles ofthe roof system with proper flashing and sealing. Appropriatedesign, materials, instal
48、lation, and maintenance are essential tothe durability of the roof integration.FIG. 1 Example of Flashing Integration with Asphalt Shingle Roof System, Top View (left) and with Overlapping Tiles (right)E2766 1337.1.2 For shingled roof systems, the mounting feet shall beintegrated under the shingles
49、in correct shingle fashion. SeeFig. 1 for an example using asphalt shingles. If shingles wereremoved to attach the flashing, the shingles shall be reattachedafter the installation of the flashing components. New shinglesshall be applied if the prior shingles are damaged.7.1.3 For roof systems other than asphalt shingles, such astile, slate, wood, synthetic or standing seam metal roofsystems, follow the recommendations of the LDP.7.2 Drainage Around and Under the ArrayThe photovol-taic array shall be designed and installed in such a man
