Yingli Solar PV Modules, Installation and User Manual
page 4
damage of the cable and/or the module is avoided. Maintain a minimum cable
bending radius greater or equal than five times the cable diameter. Route
the cable in a way that the tensile stress on the conductor or connections is
prevented. For fixing, use appropriate means, such as sunlight resistant cable
ties and/or wire management clips specifically designed to attach to the PV
module frame. While the cables are sunlight resistant and waterproof, where
possible, avoid direct sunlight exposure and water immersion of the cables.
Connectors
Protect unplugged connectors against moisture, dust
and any environmental pollution. Only clean and dry
plugged connectors fulfill their ingress protection (IP)
class. Ensure that connector caps are hand tight before
connecting the modules. Do not attempt making an
electrical connection with wet, soiled, or otherwise
faulty connectors. Avoid sunlight exposure and water immersion of the
connectors. Avoid connectors resting on the ground or roof surface.
Faulty connections can result in arcs and electrical shock. Check that all electrical
connections are securely fastened. Make sure that all locking connectors are
fully engaged and locked.
Connectors of different manufacturers must not be mated. If necessary the
connection of modules can be made by technical personnel after the connector
has been exchanged for one of the same manufacturer. Guarantee and warranty
claims are not affected by a professional exchange.
Figure 5: Series interconnection of a male (-) and female (+) connector
The junction boxes used with Yingli Solar PV 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
module heating and performance losses. Bypass diodes are not overcurrent
protection devices.
Bypass diodes divert current from the cell strings in the event of partial
shading. See Figure 6 for a diagram showing how the cell strings are electrically
connected with the diodes.
Figure 6: Electrical circuitry of cells and bypass diodes
In the event of a known or suspected diode failure, installers or maintenance
providers should contact the company the PV modules were purchased from.
Never attempt to open the junction box of a Yingli Solar PV module yourself;
replacing diodes inside the junction box is not permitted.
Equipment Grounding
The frame of the PV module, as well as any exposed non-current-carrying metal
parts of fixed equipment that are able to become energized by the PV system,
must be connected to the equipment grounding conductor in order to prevent
electrical shock. Refer to section 250 of the NEC for specific instructions on
grounding. Even when applicable regulations, code requirements, and standards
do not require safety-related grounding, Yingli Solar recommends grounding all
PV module frames in order to ensure the voltage between electrically conductive
equipment and earth ground is zero in all circumstances. A PV module with
exposed conductive parts is considered to be in compliance with UL 1703 only
when it is electrically grounded in accordance with the instructions presented
below and the requirements of the National Electrical Code.
Proper equipment grounding is achieved by bonding all exposed non-current-
carrying metal equipment continuously to one another using an appropriately
sized equipment grounding conductor (EGC) or racking system that can be used
for integrated grounding (see Option C in Grounding Methods below).
Yingli Solar PV modules employ a coated aluminum frame for corrosion
resistance. In order to properly ground the module frame, the coating must be
penetrated.
Grounding wire use copper wire with minimum 12 AWG insulated for a
minimum 90 ºC.
The potential for corrosion due to the electrochemical action between dissimilar
metals in contact is minimized if the electrochemical voltage potential between
the dissimilar metals is low. The grounding method must not result in the direct
contact of dissimilar metals with the aluminum frame of the PV module that
will result in galvanic corrosion. An addendum to UL 1703 recommends metal
combinations not exceed an electrochemical potential difference of 0.5 Volts.
The frame rails have pre-drilled holes marked with a grounding sign, as
illustrated in Figure 7. These holes should be used for grounding purposes and
must not be used for mounting the PV modules. Do not drill additional holes
into the frame rails.
Where common grounding hardware (nuts, bolts, star washers, spilt-ring lock
washers, flat washers and the like) is used to attach a listed grounding/bonding
device, the attachment must be made in conformance with the grounding
device manufacturer’s instructions.
Figure 7: Grounding hole detail
The following grounding methods are available:
Option A: Grounding Lugs
Manufacturer
Part Number
Material
Tightening Torque
ILSCO
GBL-4DBT
Tin-plated copper
20 to 25 in-lbf
(2.3 to 2.6 N∙m)
Burndy
®
CL501-TN
Tin-plated copper
20-25 in-lbf
(2.3 to 2.6 N∙m)
Tyco Electronics
SolKlip
1954381-4
Nickel and
tin-plated copper
15 +4.4/-1.7 in-lbf
(1.7+0.5/-0.2 N∙m)
Table 2: Grounding lug specifications
Grounding Holes
ø0.236in (6mm)
Fully engage and lock
Cap
+
–
