Install Manual

Document Number: MAN-SSI-02 | SAFETY AND INSTALLATION MANUAL FOR PHOTOVOLTAIC MODULES
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9.2 Functioning Grounding
For installations located in tropical regions (between 23.5o N
and 23.5o S), functional grounding at the negative pole of the DC
side of the system must be implemented.
• Ensure the dierence in potential between the negative pole
of the DC array and the negative end of the DC side of the
inverter input terminals is 0V.
• Follow the directions of the inverter manufacturer and pre-
vailing local regulations.
• Only use inverters which include licensed grounding kits.
• Functional grounding is required to be implemented in in-
stallation sites with increased salt content in the air. (e.g.
close the sea, defined as less than 500m from a coastline).
9.3 Protective Grounding
In order to prevent electrical shock or fire, the frame of the
module as well as any non-current carrying metal parts of the
system must be electrically grounded. While this section provides
some information about grounding Silfab’s frames and modules,
reference should be made to local statutes and regulations for
specific requirements on grounding. As an additional resource,
reference the U.S. National Electrical Code addresses equipment
grounding/bonding requirements in Article 250. You may also refer-
ence Canadian Electrical Code requirements located in CSA C22.1.
Proper grounding is achieved by bonding all exposed
non-current carrying conductive parts to the appropriately sized
equipment grounding conductor (EGC) or racking/rail system
that has been tested and verified to be used as a means of inte-
grated grounding.
Silfab’s frames are protected from corrosion via an anodized
coating. This coating must be penetrated in order to ensure prop-
er bonding for equipment grounding requirements. The dierent
methods outlined below are suggested methods to establish an
appropriate bond between the frame and the EGC or racking sys-
tem. The installer must ensure that the ground path of the EGC or
racking system follows proper grounding requirements.
Option A: Use of a grounding lug
A UL listed grounding lug can be bonded to the grounding
hole located on the bottom flange of Silfab’s module frame. The
holes are marked with an electrical ground symbol.
To install the grounding lug, follow the specified instructions
of the manufacturer. The grounding lug should be made of stainless
steel or tin plated metals such as aluminum to avoid corrosion. The
grounding lug should be attached to the frame grounding hole using
stainless steel hardware (screw, toothed lock washer or KEPS nut). A
lock washer or other locking mechanism is required to maintain ten-
sion between the bolt and assembly; Silfab recommends a torque
value of 25inch-lbs. The conductor must be attached to the ground
lug using the lug’s set screw. Refer to NEC Article 690. Care should
be taken to avoid the use of grounding hardware of dissimilar met-
als which may lead to corrosion. Ensure that the grounding area for
the connection is clean and free from oxides and/or any debris that
could impede the pathway for the electrical ground. Always follow
safety procedures when installing any grounding/mounting system.
Option B: Integrated grounding methods
A Silfab module can be bonded with a racking/rail system
using a UL1703 or UL2703 certified integrated grounding method.
The racking/rail system will then have to be electrically grounded
in such a way that the overall system is properly grounded per
local requirements and regulations such as what is defined in NEC
article 250 or Canadian CSA C22.1.
One example of an integrated grounding method is the use
of a washer recognized as meeting UL2703 requirements be-
tween the module and the racking/rail system, and is listed on
UL’s product database. An example of a UL2703 recognized in-
tegrated grounding method is a WEEB washer which Silfab has
found to be generally compatible with Silfab modules, however
each combination of module/racking system requires a specific
WEEB washer size. It is the responsibility of the installer to ensure
that that the specific size requirement has been met and is used
appropriately per the manufacturer’s installation manual. Note,
WEEB washers are intended for single-use only; they must not be
reused aer removal or loosening. Refer to Wiley’s installation in-
structions for the specific use of WEEB washers.
Other grounding methods may be used in conjunction with
a module mounting system tested to UL2703. For these installa-
tions, the Silfab module and frame style must be tested and part
of the instructions for the listed mounting product. The Silfab
module must be installed in accordance with these instructions
as well as the mounting system’s listed instructions.
As a final reminder, both Option A and Option B must be
grounded as per NEC Article 250 or CSA C22.1, whichever may ap-
ply to your local jurisdictional and code requirements.
9.4 Silfab (SIL-XXX XL) Bifacial Modules
Bi-facial modules are able to capture and convert light from
both the front and back surface of the module, as shown FIGURE
6. As a result, Levelized Cost Of Electricity (LCOE) can be further
reduced with bifacial technology through rear-side generation
up to 20% annual gain. This section outlines the fundamental
components for consideration to maximize power output of your
bi-facial PV system.
Step #1: Highest Surface Reflectivity/Albedo
• Performances of bifacial PV modules are linearly dependent
on the albedo.
• Best results: crushed white rock, bright white paint, or an
ENERGY STAR™ roof.
Step #2: Select the optimum height of installation & mounting
structure
• Elevate the module above as much as possible, as it will cap-
ture more ground-reflected light.
• For flat ground/rooop installation it’s recommended a min-
imum height of 50-70 cm (19 11/16 – 27 9/16”).
• Avoid shading the back side of the module from the support
rack as much as possible.
Step #3: Tilt angle of modules
• Case-by-case based on site location. For site specific energy
yield analysis and power reports, please contact Silfab Solar.