07
Parallel Connection
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The solar modules may be combined in parallel to
produce the desired current output.
•
When modules are combined in parallel, the total
current is equal to the sum of currents from each
module.
•
The voltage of each module connected in parallel
should be the same.
•
When connecting plural strings of modules in parallel
every series string or solar module must be fused prior
to combining with other strings.
•
Abide with all applicable federal, state, and local codes
for additional fusing requirements and limitations on
the maximum number of solar modules in parallel.
Earth Grounding
•
All work must be conducted in conformance with all
Federal, State, and local codes and standards.
•
Grounding works should be performed by an
authorized installer for the safety and maintenance of
the system in accordance with all national, state and
local electrical codes and regulations and standards.
•
Where common grounding hardware (nut, bolts,
washers) is used to attach a listed grounding device,
the attachment must be made in conformance with the
grounding device manufacturer’s instructions.
•
All hardware should be consist of corrosion resistant
material such as stainless steel.
•
There is an earth hole on the edge of the module
frame. Using this hole, an earth conductor and the
solar module frame may be recommended to be
connected and earthed as the below drawing.
•
Bonding points to ground should be tight, secure and free
from corrosion. (Maintenance is especially important in areas
with high levels of salt in the atmosphere, such as coastal
areas and the surrounding seas.)
•
To prevent electric shock and fire, a protective ground
must be done on the frames of solar modules and arrays
safety class II. The national directives must be respected.
although the solar modules from LG meet the conditions of
•
All screws and nuts shall be tightened to a torque of
4~5 N∙m.
Module frame
Bolt
Flat washer
Star washer
Cup washer
Grounding wire
Spring washer
Nut
Flat washer
•
Maximum series fuse rating is refer to “Product
Specifications; page 11”.
Parallel connection for more current
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LG Electronics recommends a size no smaller than
4mm .
2
General Wiring
•
LG Electronics recommends that all wiring be double
insulated with a minimum rating of 90°C (194°F).
•
The minimum size should be determined by the
applicable codes.
•
All wiring should use a flexible copper (Cu) conductor.
and location of grounding holes is provided in “Product
•
Specific information on the solar module dimensions
Specifications”.
•
One M4 stainless steel bolt, one nut, one spring
washer and 12 AWG Cu wires are recommended per
mounting hole.
washer, two flat washers, one cup washer, one star
•
A multiplying factor is required for increased output
of the PV modules. Under normal conditions, a PV
module is likely to experience conditions that produce
more current and/or voltage than reported at standard
test conditions. The requirements of the National
Electrical Code (NEC) in Article 690 shall be followed
to address these increased outputs.
The values of Isc and Voc marked on this PV module
should be multiplied by a factor of 125% when
determining component voltage ratings, conductor
ampacities, fuse sizes, and size of controls to the PV
output.
•
Depending on national directives, additional safety
factors might be applicable for over current protection.
•
Parallel configuration is not limited if proper measures
are taken to block the reverse current flow, e.g. fuses
for the protection of the module and cables from over
current.
•
LG Electronics recommends to take blocking diode for
prevention of unbalaced string voltage.
•
The reverse current flow in the string may be caused
by a module short circuit, incorrect wiring, shadow, etc.
•
Blocking diodes must have :
1) VRRM(Repetitive Peak Reverse Voltage) :
1.5times of maximum system voltage
2) IF (Average Forward Current) :
2 times of Isc (PV module short circuit current)
※
It is selected in consideration of the thermal
characteristics of the diode, and it is recommended
to use a component of 30mA or less for IRRM
(Repetitive Peak Reverse Current, max).
