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© 2011-2013 Silfab Ontario Inc. - Specifications in this manual are subject to revisions without notice
SAFETY AND INSTALLATION MANUAL FOR
PHOTOVOLTAIC MODULES
The junction box does not require any extra
field wiring at the terminals. (Changing wires
or modifying any piece of the junction box,
including the bypass diodes will void the
module warranty.)
7c) Electrical Connection
Danger! Risk of serious injury or death from
electric shock or electric arc flash! Do not
connect or disconnect modules under load!
Even if the modules are protected against
accidental
contact, under unfavorable
conditions high hazardous voltage (several
hundreds of volts) may occur during
installation. Consequently, installation and
maintenance of the modules, as well as the
connection to the main power supply, may
only be performed by authorized and qualified
persons.
Before connection of the system to the grid,
the PV system must be approved for correct
installation, by an electrician responsible to
the operator and the local electricity
company.
The design of the PV system should be done by
a qualified person familiar with PV system
design. The system design is the responsibility
of the PV system designer. Therefore, SILFAB
does not assume any liability for how the
modules are installed.
The junction boxes used with SLA/SLG modules
contain bypass diodes wired in parallel with
the PV cell strings. In the case of partial
shading, the diodes bypass the current
generated by the non-shaded cells, thereby
limiting the module’s heating and
performance losses. Bypass diodes are not
over-current protection devices.
In the event of a known or suspected diode
failure, installers or maintenance providers
should contact Silfab.
Never attempt to open
the junction box by yourself!
Under normal conditions, a PV module is likely to
experience conditions that produce more current
and/or voltage than reported at STC. Accordingly,
the values of I
sc
and V
oc
marked on the module
should be multiplied by a factor of 1.25 when
determining component voltage ratings,
conductor current ratings, fuse sizes, and size
of controls connected to the PV output.
Refer to
NEC 690.8 (B) for an additional 1.25 multiplier
that may be required for sizing fuses and
conductors.
•
V
oc
should be increased by a factor according
to the lowest ambient air temperatures
expected for the installation site. Refer to NEC
690.7 for the correct V
oc
correction factor
according to the respective temperatures. If
this information is not available, a 1.25
multiplying factor can be used as default value
for correction of V
oc
.
•
In order to obtain the required electrical
current and/or voltage, the modules can be
connected in series, in parallel, or in a
combination of both.
o
In the case of series connection, do not
exceed the maximum system voltage of
600V even at low temperatures. Always use
the same type and rating of module in one
installation!
o
In the case of parallel connection of
modules or series strings of modules, fusing
may be required. Information about the
fuse rating can be found on the module’s
nameplate and in the datasheet – see also
NEC 690 for additional fusing requirements.
o
The voltage of the strings of modules, in
series, when measured at their poles, is
the sum of all the individual voltages of
