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  • SLK Solar Corp. microFIT Ground Mount System Technical Guide Rev B Page 1 of 19

    SLK SOLAR CORPORATION

    MICROFIT GROUND MOUNT SYSTEM TECHNICAL GUIDE

    TABLE OF CONTENTS

    Notices and safety precautions Page 2 System description and elevation view Page 3 Part diagrams and specifications Page 4 Array layout guidelines Page 6

    A. Layout terminology Page 6 B. Panel sizes Page 7 C. Inter-row spacing Page 7 D. East/west post spacing Page 7 E. Elevation and orientation Page 8 F. Sample layout Page 9

    Foundations Page 10 A. Helical screw pile post Page 10 B. Reinforced concrete pier Page 11

    1. Base plate with anchor bolts Page 11 2. Embedded post Page 13

    C. Design parameters Page 14 Assembly instructions Page 15

    A. General procedure notes Page 15 B. Installation materials and tools Page 15 C. Assembly sequence Page 15 D. Detailed assembly instructions Page 16

  • SLK Solar Corp. microFIT Ground Mount System Technical Guide Rev B Page 2 of 19

    NOTICES AND SAFETY PRECAUTIONS Read this document before beginning installation work. Plan for safe practice during any installation activity with respect to hazards from tripping, falling, lifting, repetitive stress and any overhead or electrical hazards.

    This document is not prescriptive regarding safety and does not purport to address all the safety concerns that may arise with its use. Installers should become familiar with all applicable safety, health and regulatory requirements before beginning work.

    Electrical safety notice Any time an SLK Solar panel contains two or more electrically interconnected modules, a shock hazard is present. SLK Solar microFIT Ground Mount System is a mechanical system and contains no live parts. Mechanical installers and electricians should coordinate in order to ensure that all personnel are aware of electrical hazards.

    Precedence The SLK Solar microFIT Ground Mount System positions and secures photovoltaic modules. DC stringing and interconnection of the modules requires placement of conduit, conduit fittings and combiner boxes.

    Field modifications Unauthorized field modification of SLK Solar components or assemblies may affect SLK Solars warranty coverage. Tubes or pipes may be cut to length if desired.

    Fasteners All required fasteners are furnished with the SLK Solar microFIT Ground Mount System. For any assembly, finish initial bolted assembly to finger tight. Read this Technical Guide fully for detailed information on application. Button-head cap screws (BHCS) are precision, low-profile fasteners. Use of air-powered tools that do not incorporate means to limit applied torque may damage the head of these fasteners and is not recommended. Anti-seize lubricant is recommended to prevent galling of stainless steel fasteners.

    Units of measurement This document provides information in both imperial units (e.g. inches) and metric units (e.g. millimeters). Module specification sheets often provide information in metric units only. It is the users responsibility to convert between imperial and metric measurement systems where necessary and to employ a consistent system of units for all calculations.

  • SLK Solar Corp. microFIT Ground Mount System Technical Guide Rev B Page 3 of 19

    SYSTEM DESCRIPTION AND ELEVATION VIEW The SLK Solar microFIT Ground Mount System is designed to meet all the requirements of the Ontario Power Authoritys Feed-In-Tariff (FIT) program, including requirements for domestic content. The system assembles photovoltaic modules into panels. Each panel is comprised of up to eight modules in portrait orientation.

    Some key aspects of the system are:

    1. 30 fixed tilt angle 2. Universal parts designed to accommodate a wide variety of modules 3. Can be completely assembled with commonly available tools by persons possessing average mechanical ability

    NOTE: Post type and size is dependant on several factors. See Foundations section for details regarding post selection.

    Clamp, panel upper

    Post

    Post frame

    Post cap Vee plate

    Clamp, panel lower

    Panel mounting tube

    Module

  • SLK Solar Corp. microFIT Ground Mount System Technical Guide Rev B Page 4 of 19

    PART DIAGRAMS AND SPECIFICATIONS

    Post frame

    ASTM A123 hot-dip galvanized ASTM A513 carbon steel tubing ASTM A572 grade 50 flat stock

    Panel mounting tube

    ASTM A123 hot-dip galvanized 2 7/8 nominal outer diameter, 8 gauge ASTM A500 carbon steel tubing

    Clamp, panel upper

    Die cast aluminum, A380

    Clamp, panel lower

    Die cast aluminum, A380

    Post cap

    Hot-dip galvanized ASTM A513 carbon steel tubing ASTM A572 grade 50 flat stock

    Vee plate

    ASTM A123 hot-dip galvanized ASTM A36 flat stock

  • SLK Solar Corp. microFIT Ground Mount System Technical Guide Rev B Page 5 of 19

    Cable clip

    304 stainless steel

    Tube post*

    ASTM A123 hot-dip galvanized ASTM A513 carbon steel tubing

    Flanged post

    ASTM A123 hot-dip galvanized ASTM A513 carbon steel tubing ASTM A572 grade 50 flat stock

    Screw pile post*

    ASTM A123 hot-dip galvanized ASTM A252 grade 2 or 3 pipe shaft CSA G40.21 44W (300W) helix plate CSA W59 and CSA W47.1 welded

    *supplied by others

  • SLK Solar Corp. microFIT Ground Mount System Technical Guide Rev B Page 6 of 19

    ARRAY LAYOUT GUIDELINES A. LAYOUT TERMINOLOGY

    1. Side View (West-looking)

    2. Rear View (South-looking)

    The following dimensions are important to keep in mind when laying out the SLK Solar microFIT ground mount system.

    module-to-module spacing 0.375 in. (typically)

    panel-to-panel spacing 6 in. (minimum)

    NOTE: In this manual, module refers to a single photovoltaic module. A panel is group of modules assembled into a unit with two Panel Mounting Tubes.

  • SLK Solar Corp. microFIT Ground Mount System Technical Guide Rev B Page 7 of 19

    B. PANEL SIZES The SLK Solar microFIT ground mount system assembles photovoltaic modules into panels as follows:

    8x1 - 8 modules assembled into one panel 7x1 - 7 modules assembled into one panel 6x1 - 6 modules assembled into one panel 5x1 - 5 modules assembled into one panel 4x1 - 4 modules assembled into one panel

    For a given microFIT system, a combination of the above panel sizes will accommodate the total number of modules available. For example, one panelization option for a project consisting of 39 modules may be four 8x1 panels and one 7x1 panel (as shown in F. Sample Layout). Selection of panel configurations is ultimately up to the system designer, however usage of 8x1 panels should be maximized in order to minimize cost and install time.

    SLK Solar ships panel mounting tubes are sized for 8x1 panels. This standard length is based on the widest photovoltaic module commonly available. Other panel sizes may be created by either omitting modules from an 8x1 panel assembly, or by cutting the panel mounting tubes to length.

    C. INTER-ROW SPACING (NORTH/SOUTH POST SPACING) Optimal inter-row spacing is dependent on many factors including site latitude, available land area, shading and other factors, all of which affect system performance. The calculation of inter-row spacing can be generalized for any module length by introducing the ratio d/h (distance over height see A. Layout Terminology). System designers typically simulate yearly output to determine an acceptable d/h value. With a d/h value selected, inter-row spacing for the SLK Solar 30 microFIT system may be calculated as:

    inter-row spacing = (module length) 0.5 + .866

    D. EAST/WEST POST SPACING In the east/west direction, posts should be spaced between 52% and 62% of the total panel length. Furthermore, a minimum gap of three (3) inches should be maintained between vee plates and panel clamps. These guidelines apply to all panel sizes and are illustrated in the diagram below for an 8x1 panel. The shaded areas in the diagram represent the range of acceptable post spacing. Note the panel must extend beyond the post an equal distance on each side.

    8x1 panel post spacing

  • SLK Solar Corp. microFIT Ground Mount System Technical Guide Rev B Page 8 of 19

    E. ELEVATION AND ORIENTATION The solar modules should be oriented as close to due south as possible in order to maximize power production. All arrays

    should be parallel. The panel tubes must be installed level. Irregularities in ground level in the east-west direction can be made up by adjusting the post height above grade. This dimension will impact on foundation requirements.

    The south edge ground clearance is the nearest point between the solar module and the ground. In order to minimize the possibility of coverage of the solar modules by snow accumulation on the ground and to ensure that snow landing on the modules has sufficient void into which it can slough off, the south edge ground clearance should be no less than the design depth of snow as derived from the relevant building code for that area.

    The south edge ground clearance is a function of the post height above grade and the length of the solar module being employed. To achieve a desired ground clearance, post height may be calculated as:

    post heightabove grade = 0.5 module

    hole-to-edgedistance

    + south edgeground clearance H

    NOTE:

    1. post heightabove grade, module

    hole-to-edgedistance

    , and south edgeground clearance are defined in the diagram below.