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EN-Rev IM/GN-BM-EU/1.8 Copyright © March, 2021. CSI Solar Co., Ltd.
www.csisolar.com
box provided may vary depending on the model series.
Only connect the quantity of modules that corresponds
to the voltage specifications of the inverters used in the
system. In addition, modules must not be connected
together to create a voltage higher than the maximum
permitted system voltage stated on the module
nameplate, even under the worst local temperature
conditions (see Table 1 for the correction coefficients
that apply to open-circuit voltage).
A maximum of two strings can be connected in parallel
without using an over-current protection device (fuses,
etc.) incorporated in series within each string. Three or
more strings can be connected in parallel if an
appropriate and certified over-current protection
device is installed in series within each string. And it
shall be ensured in the PV system design that the
reverse current of any particular string is lower than the
module maximum fuse rating at any circumstances.
Only modules with similar electrical parameters should
be connected in the same string to avoid or minimize
mismatch effects in arrays.
To minimize risk in the event of an indirect lightning
strike, avoid forming loops with the wiring when
designing the system.
The recommended maximum series fuse rating is
stated in a table in the Annex A.
Modules should be safely fixed to bear all expected
loads, including wind and snow loads.
After the installation of double glass modules, a 30 mm
deflection for framed module is allowed.
For framed modules, a minimum clearance of 6.5 mm
(0.25 in) between modules is required to allow thermal
expansion of the frames and modules.
OPTIMUM ORIENTATION AND TILT
To maximize the annual yield, please calculate the
optimum orientation and tilt for PV modules in that
specific installation site. The highest yields are achieved
when sunlight shines perpendicularly onto the PV
modules.
AVOID SHADING
Even minor partial shading (e.g. from dirt deposits)
reduces yields. A module can be considered to be
unshaded if its entire surface is free from shading all
year round. Sunlight should be able to reach at least the
module even on the shortest day of the year.
For optimizing the power generation of the rear side of
bifacial modules, obstacles between modules and the
mounting ground should be avoided as much as
possible
Constant shading conditions can affect module service
lifetime, due to accelerated ageing of the encapsulation
material and thermal stress on the bypass diodes.
RELIABLE VENTILATION
Bifacial modules use direct, reflected, or diffuse
sunlight on the backside to generate additional power.
Therefore, bifacial modules are not suggested to be
used in building attached photovoltaic systems (BAPV).
If BAPV, or similar mounting is still required, sufficient
clearance of at least 10 cm (3.94 in) between the module
and the mounting surface needs to be provided to allow
cooling air to circulate around the back of the module.
This also allows condensation or moisture to dissipate.
According to UL 1703, any other specific clearance
required for maintaining a system fire rating should
prevail. Detailed clearance requirements pertaining to
system fire ratings must be provided by your racking
supplier.
5.1 MODULE WIRING
CORRECT WIRING SCHEME
Ensure that the wiring is correct before starting up the
system. If the measured open circuit voltage (Voc) and
short-circuit current (Isc) differ from the specifications,
this indicates that there is a wiring fault.
When modules have been pre-installed, but the system
has not been connected to the grid yet, each module
string should be kept under open-circuit conditions and
proper actions should be taken to avoid dust and
moisture penetration inside the connectors.
Do not connect different connectors (brand and model)
together.
