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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


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 Solar’s 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 user’s responsibility to convert between imperial and metric measurement systems where necessary and to employ a consistent system of units for all calculations.


SYSTEM DESCRIPTION AND ELEVATION VIEW The SLK Solar microFIT Ground Mount System is designed to meet all the requirements of the Ontario Power Authority’s 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


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


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


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.


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 × �𝑑 ℎ� � + .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


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-edge

distance� + � south edge

ground clearance� − ΔH

NOTE:

1. � post heightabove grade�, �

module hole-to-edge

distance�, and � south edge

ground clearance� are defined in the diagram below.

2. The module hole-to-edge distance can be measured on the module itself or extracted from the module manufacturer’s

specifications.

3. The value of ΔH is tabulated by module hole spacing and may be found in this technical guide under Detailed Assembly

Instructions, step 4.

EXAMPLE:

To achieve a south edge ground clearance of 4 feet with a module hole-to-edge distance of 15.35 inches and a ΔH of 3.47 inches, the required post height above grade would be:

� post heightabove grade� = (0.5 × 15.35") + 48"-3.47" = 52.21"

ΔH


F. SAMPLE LAYOUT The diagram below illustrates one potential layout for an installation containing 39 solar modules.

Sample Layout Summary number of modules 39 8x1 panels four (4) 7x1 panels one (1) module length 77 in. module width 39 in. d/h 3.1 inter-row spacing 186 in. 8x1 panel post spacing 180 in. 7x1 panel post spacing 157 in.

8x1 panel post spacing 7x1 panel post spacing

inte

r-ro

w sp

acin

g

Panel-to-panel spacing 6 inch minimum


FOUNDATIONS

The SLK Solar microFIT Ground Mount System can be installed using a number of different foundation arrangements. Indicative details of three foundation options are presented here for planning and estimating purposes. These include:

1. Helical pile post. 2. Cast in place concrete pier, employing either:

a. Flanged post and anchor bolts; or b. Embedded post.

These indicative foundation arrangements are each described in relation to nine different soil conditions. These nine soil types are defined at the end of this section together with all other assumptions that underlie these indicative foundation designs.

These foundation designs are for planning purposes only and actual foundation requirements may vary depending on in-situ soil and other conditions. Actual soil parameters and design loads should be verified by a professional engineer. Installations must comply with all applicable building regulations and bylaws and be in accordance with best engineering and construction practice.

A. HELICAL PILE POST

The helical piles shown in these designs are as supplied by Almita Piling Inc. of Guelph, Ontario, 1-800-363-4868. Piles of an equivalent or better performance may also be used.

Helical Pile Foundation Elevation

*Refers to proprietary designations of Almita Piling Inc.

(4’ 6” max)


B. REINFORCED CONCRETE PIER The reinforced concrete pier designs presented below were produced by Strik, Baldinelli & Associates of London, Ontario

(519) 471-6667. These are not sealed engineering drawings. If sealed drawings are required, contact Strik, Baldinelli & Associates.

The two reinforced concrete pier designs are common in that they employ a concrete foundation to transfer the loads from the solar array to the ground. The array is connected to the concrete foundation either via anchor bolts that engage a base plate at the bottom of the vertical post (flanged post) or by the vertical post (tube post) embedding directly in the concrete.

The flanged post is 36.5” long. In order to achieve a Post Height above Grade in excess of this the pier must extend above grade by the appropriate distance. For both types of concrete pier, the pier should extend a minimum of 6” above grade to minimize the chance of surface water coming into contact with the vertical post. In cases where the tops of two piers in an array are not in plane due to irregularities in ground level, the top of piers as designed here may extend to a maximum of 18” above grade.

FLANGED POST AND ANCHOR BOLTS

** Minimum height of D section (bell) is 8”

Cast in Place Concrete Pier with Flanged Post and Anchor Bolts

Elevation

*Pier diameters specified assume pier is uncased. If a Sonotube® or equivalent casing is provided, pier diameter may be reduced by up to 2”.


Two fastening options are available for use with the flanged post system - cast in place anchors or epoxy anchors. Cast in place anchors are cast in the pier during placement of concrete, whereas epoxy anchors are drilled and epoxied into the pier once concrete has cured. For epoxy anchors, follow all manufacturers’ safety and installation guidelines.

The flanged post base plate is permitted to sit a maximum of 2” above the top of the concrete pier to allow for fine-tuning of post heights. However, post height above grade is not to exceed 4’ 6”.

Plate washers and hex nuts should be placed on either side of the flanged post base. The plate washers should be, HDG, A36 material, ¼” x 2” x 2” with a 13/16 diameter hole.

POWERS AC100 PLUS™ OR

EQUIVALENT EPOXY


EMBEDDED POST

1. Embedded post consists of a straight post with 3-20M bars, 24” long, crossed at 60° at the bottom. Post must be embedded a minimum of 36” into concrete pier.

2. Embedded post must be fully shored during placement of concrete to ensure post remains centered in pier and perfectly true/plumb. Height of posts must be adjusted before concrete sets. Maximum height of the post above grade is 4’ 6”.

Cast in Place Concrete Pier

with Embedded Post Elevation

All pier details (e.g. dimensions and reinforcing) are identical to the Cast in Place Concrete Pier with Flanged Post and Anchor Bolts.


C. DESIGN PARAMETERS These indicative foundation designs are based on a number of assumptions about the layout of the photovoltaic system as

well as meteorological and soil conditions.

The designs shown above assume a design wind loading of q50 = 0.55 kPa and snow loading of Ss = 2.4 kPa. Any regional deviations from these loadings will require engineering design beyond the scope of this manual.

The assumed geometry of the array is:

1. 8 modules wide 2. The solar modules are a maximum of 78.7” in length and have a surface area no greater than 21.56 ft2 3. The vee plates are mounted as per these Assembly Instructions to center the solar modules over the vertical post

as much as possible 4. Height of post does not exceed 4’ 6” above grade

The actual foundation design employed should reflect any differences between this assumed geometry and the array being installed.

The following soil types have been referenced in the above indicative foundation designs.

The assumed unit weights used when applying these soil profiles are as follows:

• Topsoil = 95 lb/ft3 • S.P.T. 5-15 = 115 lb/ft3 • S.P.T. 15-25 = 130 lb/ft3 • S.P.T. 25-50 = 140 lb/ft3

The assumed soil bearing capacities are:

• S.P.T. 5-15 : qa = 1500 psf / 72 kPa • S.P.T. 15-50 : qa = 3000 psf / 143 kPa

Actual in-situ soil conditions should be verified by a professional engineer.


ASSEMBLY INSTRUCTIONS A. GENERAL PROCEDURE NOTES 1. At the end of every work day ensure all components are securely attached. 2. Be careful of pinch hazards, especially when lowering tubes onto vee plates. B. REQUIRED INSTALLATION MATERIALS AND TOOLS 1. Torque wrench 2. Cordless screwdrivers with torque adjustment 3. 9/16” wrenches and deep sockets 4. 1-1/8” wrenches 5. 3/4" wrenches 6. Impact wrench 7. Tape measure 8. Hex bit drivers - 3/16” or 5/32” (depending on module mounting holes) 9. 1/2” drill bit C. ASSEMBLY SEQUENCE 1. Install posts (tube posts, flange posts, or screw pile posts). 2. Attach post cap to post. 3. Attach post frame onto post cap. 4. Install vee plates onto post frame. 5. Install panel mounting tubes onto vee plates on post frame and slide on pre-assembled panel clamps. 6. Secure mounting tubes to vee plates using U-bolts. 7. Attach modules to panel clamps. 8. Drill through post and secure to post cap. 9. Ground system and hook up module leads.


D. DETAILED ASSEMBLY INSTRUCTIONS Step 1.

Prepare ground and install posts (tube post, flange post, or screw pile post) as described in sections “Array layout guidelines” and “Foundations.” Ensure posts are plumb, square and set at the correct height.

Step 2.

Place post cap over top of post tube and orient such that slots in plate are in the north south direction and one set screw is on the north side of the tube. The post cap may be lifted up to two (2) inches to ensure it is level with other post caps in the row. Use the sight hole (located just above the north set screw) to confirm the post cap is not lifted more than two inches. Screw in the set screws and tighten to 50-60 ft lbs of torque. Lock in jam nut to secure set screw in position.

Step 3.

Attach post frame to post cap with the post frame sloping towards the south. Slots in post frame and post cap allow adjustment in the north-south direction. Insert four (4) 1/2-13 x 1 1/2” hex head cap screws (HHCS) with eight (8) 1/2” washers and four (4) 1/2" hex nuts through the mounting slots. Once frames are aligned along a row tighten nuts to a torque of 40-45 ft lbs.

Post frame

Post cap Post tube

North

South

Jam nut

Set screw

Sight hole


Step 4.

Determine module mounting hole spacing dimension (long side spacing – see A. Layout Terminology). This dimension is commonly found on the module specification sheet. Using the table and diagram below, determine applicable post frame holes and slots. Loosely attach vee plates to appropriate post frame holes and slots using four (4) 3/8-16 x 2 1/4” HHCS with four (4) 3/8” flat washers and four (4) 3/8” hex nuts. Prior to tightening, adjust upper vee plate within slots such that vee plate spacing precisely matches module mounting hole spacing dimension. If this spacing is set imprecisely, the upper vee plate may require readjustment during step 7. Once satisfied with spacing, torque nuts to 16 - 20 ft lbs.

NOTE: 1. Vee plates can be attached to post frames prior to frames being attached to post caps to reduce on-site labor. 2. ΔH is used to calculate post height. See Foundations section for details.

Module Mounting Hole Spacing (Long Side) [mm] Holes Slots ΔH [in] 775 - 812 10, 12 A, B 6.59 813 - 850 9, 11 A, B 5.84 851 - 889 8, 10 A, B 5.09 890 - 927 7, 9 A, B 4.34 928 - 965 6, 8 A, B 3.59 966 - 1003 5, 7 A, B 2.84 1004 - 1041 4, 6 A, B 2.09 1042 - 1079 3, 5 A, B 1.34 1080 - 1117 2, 4 A, B 0.59 1118 - 1155 1, 3 A, B -0.16 1156 - 1193 2, 4 B, C 0.59 1194 - 1231 1, 3 B, C -0.16

Orient vee plates

as shown

Slot:

A B C Hole:

1

2

3

4

5

6

7

8

10

9

11

12


Step 5.

Install panel mounting tubes into vee plates and orient tubes crown up. Use tape measure to ensure panel mounting tubes are centered. Assemble clamps, panel upper and lower using 3/8-16 x 2 1/2" Hex bolts and 3/8” flat washers and 3/8” hex nuts. Slide pre-assembled panel clamps onto mounting tube oriented such that module mounting slot tabs are facing up. Attach cable clip to clamps on upper panel mounting tube.

Step 6.

Secure mounting tubes to vee plates using 3/8-16 U-bolts with 3/8” flat washers and 3/8” hex nuts. Torque nuts to 14-18 ft lbs.

Module mounting slot tabs

Cable clip attached to panel clamps on upper tube


Step 7.

Attach modules to panel clamps using either 1/4-20 x 5/8” BHCS or 5/16-18 x 5/8” BHCS (depending on modules) and flange nuts. Orient modules such that junction boxes are towards the top of the structure. Begin at one end and work your way across the structure to ensure even spacing between modules. Clamps on end of panels are placed on the inside of the module as shown below. Align edge of first module with outside edge of clamp tab and slightly outside tube end to ensure correct spacing. Torque screws as follows, 1/4-20 BHCS – 8 to 12 ft lbs, 5/16-18 BHCS – 11 to 16 ft lbs. Tighten 3/8” hex nuts with 3/8” flat washers on clamps evenly to 14 to 18 ft lbs to secure to mounting tubes.

Step 8.

When system is installed, recheck panel for level, if required the post cap position can be adjusted slightly to bring the panels in line. Once panel is in the correct position drill 1/2” holes in post tubes through the holes provided in the post cap and secure post cap to post tube with one (1) 1/2-13 x 5 1/4” HHCS with flat washer and hex nut. Step 9.

Following all applicable safety and electrical code requirements, fully ground the system and hook up module leads.

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SLK SOLAR CORPORATION MICROFIT GROUND MOUNT SYSTEM ...sunlink.com/uploadedfiles/Slksolar/Content/Files/GMS microFIT... · SLK SOLAR CORPORATION . MICROFIT GROUND MOUNT SYSTEM