Application Note FS Series PV Module Mounting

Transcription

1 Application Note FS Series PV Module Mounting The information contained in this application note is intended to provide designers of First Solar PV module mounting and support systems with both minimum requirements and recommendations for the development of alternative mounting solutions which will satisfy First Solar s technical and mechanical requirements to provide a safe and approved solution for the installation of the First Solar FS Series laminate PV modules. North American users please reference PD NA for Underwriters Laboratories (UL) requirements and information. The information contained in this document is not exhaustive and does not consider all technical design features, but rather provides the minimum required mounting provisions to ensure First Solar FS Series PV Modules perform in a safe and reliable manner. Compliance with these recommended requirements will not, by itself, necessarily result in a fully approved PV System design. First Solar is not responsible for the cost associated with the development or manufacture of design prototypes. Please see the appropriate First Solar FS Series PV Module User Guide for further information about the First Solar laminate PV module product in your region of application. Module Physical Specifications and Dimensions Module physical dimensions provided below are for reference only. Refer to product drawing PRD-017-A or PRD-182-A for exact dimensions and tolerances of module. Length 1200mm(-0.79mm/+5mm) [47.24 inch in/+0.197in] Width 600mm (-0.79mm/+5mm) [23.62 inch in/+0.197in] Thickness 6.8mm (±0.2mm) [.267 inch ±0.008 inch] Weight 12 kg [26.5 lb] Area 0.72m 2 [7.75 ft 2 ] Module Mounting Locations The module shall be secured to the support structure with clips (or equivalent) located at four (4) symmetrical points. The location of the clips shall be along the 1200mm [47.24 inch] length of the module, and the center point of the clip shall be located between 250mm and 300mm [9.84 inches and inches] from the module corner. Figures 1 and 2 depict typical locations for retaining clips. Page 1 of 6

2 Figure 1. Recommended Location of Retaining Clips (Front Side) Figure 2. Recommended Location of Retaining Clips (Back Side) Page 2 of 6

3 Module Orientation Specifications If the modules are to be tilted and mounted in portrait orientation, a slide-prevention feature is recommended to prevent the module from sliding out of the module clips. If the modules are to be tilted and mounted in landscape orientation, no additional slideprevention features are necessary. Retaining Clip and Mounting System Required Minimum Specifications First Solar requires that a module retaining clip and mounting system must meet the following minimum specifications: The retaining clip and mounting system (retaining system) shall not compromise the integrity of the module under the applied load as defined in IEC 61646, The retaining system shall not allow a module to deflect more than mm/mm [ inch/inch]. The clip and support rail retaining system shall be designed in combination with one another and must have a gap on the vertical edge to the module of 1mm [0.04 inches] to allow for thermal expansion in the width and length of the module glass. The retaining clip shall have a hard stop that limits the top and bottom surfaces of the insulator material compression by a maximum of 10% at maximum torque of fastening hardware. The retaining clip shall provide a gap of less than 6.8mm [0.27 inch] to allow for the thickness of the module and when installed, the insulator material shall not compress more than 10% at maximum hardware torque. Retaining Clip & Mounting System Recommended Minimum Specifications First Solar recommends that a module retaining clip and mounting system should meet the following minimum specifications: A module surface contact length of 70mm [2.76 inches] (80 mm [3.15 inches] preferred) Front side module surface contact width between 13mm (0.51 inches] and 15mm [0.6 inches] Minimum back side module surface contact width of 15mm [0.6 inches] The retaining clips may be designed to support the module from either both the front side and back side surfaces, or only the front side surface. If the clip is designed to support and retain the module only at the module s front side surface, the design and profile of the support rails to which the clips are mounted must be taken into consideration. Page 3 of 6

4 Support Rail Specifications Module support rails (or equivalent) shall be designed to provide a uniform and level plane for installation for the modules. The support rails shall be designed to support the modules, with or without (rails retain module) the use of retaining clips, either across the 600mm [23.62 inch] width of the module or along the entire span of the 1200mm [47.24 inch] length of the module (see Figures 3, 4, and 5). Figure 3: Rails supporting landscape oriented modules across the width Figure 4: Rails supporting landscape oriented modules across the length Figure 5: Rails supporting portrait oriented modules across the width (slide prevention protection recommended) Module retaining clip can be either a one-part or two-part design (separate top half and bottom half) (see Figures 6 & 7). Figure 6: Typical One-Part Clip Design Figure 7: Typical Two-Part Clip Design If a two-part clip design is used, then the width of the module rail is not specified. If a one-part clip design is used, table 1 below defines the support rail width and contact surface area width for the two different module retaining clip and support rail configurations. Module Retaining Minimum Rail Contact Rail Span Direction Minimum Rail Width Clip Type Surface Width One-Part design Along module width 40mm [1.6 in] 30mm [1.2 in] One-Part design Along modulelength Width of clip bottom Full contact with clip bottom Table 1: Support Rail Width and Contact Surface Width Requirements Module support rails shall be fabricated from corrosion and UV resistant materials (ex. pregalvanized steel, hot dipped galvanized steel, aluminum, stainless steel, powder-coated steel, etc.) that will maintain structural integrity over the lifespan of the modules (25-30 years) they support. Page 4 of 6

5 Insulators and Protective Materials Laminate modules must be electrically insulated and protected from direct contact with metallic surfaces of retaining clips, support rails, or other structural support components. Insulation and protective materials tested and approved for use by First Solar are typically Ethylene Propylene Diene Monomer (EPDM), Silicone rubber formulation, or equivalent and must have the following minimum thicknesses: Top Section: 3mm [0.12 in] minimum (includes teeth or ridges ) Bottom Section: 3mm [0.12 in] minimum (includes teeth or ridges ) Vertical Section: 2mm [0.08in] minimum Figure 8. Sample Clip Insulator defined sections Insulator materials shall be highly UV resistant and designed for 25+ year life. Typical rubber durometers range from 45 to 75 on the Shore A scale. Page 5 of 6

6 Moisture Drainage Retaining clips and support rails should be designed to facilitate good air circulation and drainage at the module interface, and should be designed to prevent the trapping of moisture inside of the clip or at the edge of the laminate module. Request To Test First Solar reserves the right to internally test samples of any proposed retaining clip and support rail designs prior to approval for use by First Solar s customers. First Solar may, at First Solar s sole discretion, test the designer s supplied samples per the procedures defined in IEC (Mechanical Load Test), UL 1703 section 41 (Mechanical Loading Test), and/or other tests deemed appropriate by First Solar. If multiple retaining clip and rail profile combinations are intended by designer, all combinations shall be disclosed to First Solar for review. Clip designers who do not intend to supply their own support rails shall supply First Solar with the specifications for the specific rail profile(s) to be used in design evaluation. It is recommended that the retaining clip owner/designer/seller perform their own static load test as defined in IEC 61646, prior to submitting samples for First Solar test and approval. Submitted System Design Approval Process Clip and rail system designers shall submit the following items to First Solar to begin the proposed support system approval process: Part drawing(s) of the proposed retaining clip and support rail with critical dimensions Assembly drawing(s) of the proposed module, retaining clip, and support rail assembly with critical dimensions Assembly instructions Description of any special tools or equipment needed for assembly (as required) Upon receiving the above items, First Solar will review the proposed design and decide to either proceed to test or reject the proposed design. A standard evaluation form will be sent in response to each proposal which will instruct the customer to send samples for testing or recommendations for redesign. Page 6 of 6