Module Wiring - Canadian Solar Standard Series Installation Manual

damage the module mechanically or electrically.
· Modules can be wired in series to increase voltage
or in parallel to increase current. To connect modules
in series, connect the cables from the positive
terminal of one module to the negative terminal
of the next module. To connect in parallel,
connect the cables from the positive terminal of
one module to the positive terminal on the next
module.
· The quantity of bypass diodes in the module's
junction box may vary depending on the model
series.
· Only connect the quantity of modules that corres-
ponds to the voltage specifications of the inverters
used in the system. In addition modules should 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 the need to incorporate an over-
current protection device (fuses, etc.) in series
within each string. Three or more strings can be
connected in parallel if an appropriate, certified
over-current protection device is installed in series
within each string.
· Only modules with similar electrical outputs
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 C.
· Modules should be safely fixed to bear all expected
loads, including wind and snow loads.
· A minimum clearance of 6.5 mm (0.25 in) between
modules is required to allow for thermal expansion
of the frames.
· The small drainage holes on the underside of the
module must not be blocked.
oPtImum oRIentatIon anD tIlt
· To maximize your annual yield, find out the
optimum orientation and tilt for PV modules
in your region. 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 the
module even on the shortest day of the year.
· 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
· Sufficient clearance (at least 10 cm (3.94 in))
between the module frame and the mounting
surface is required to allow cooling air to circulate
around the back of the module. This also enables
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 substantially 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
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