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6.4 ELECTRICAL INSTALLATION
6.4.1
SAFETY INSTRUCTION
All wiring installation should be carried out by qualified installers in accordance with local electrical
construction codes, procedures, and regulations.
Modules can be connected in series to increase the operating voltage by connecting the positive
terminal of one module into the negative terminal of the next one. Before connecting, always ensure
that the contacts are corrosion-free, clean, and dry.
The product can be irreparably damaged if an array string is connected in reverse polarity to another.
Always verify the voltage and polarity of each string before making a parallel connection. If a reversed
polarity or a difference of more than 10V between strings was detected, check the string configuration
before connection.
The standard copper cables applied in Trina Solar modules are UV resistant and with a cross-
sectional area of
≥4 mm
2
(12 AWG). All other cables applied to connect the DC system should be
provided with a similar or larger wire cross section. Trina Solar recommends that all cables are routed
in appropriate conduits or rails where water does not accumulate.
The string voltage must not be higher than the maximum system voltage, as well as the maximum
input voltage of the inverter and the other electrical devices installed in the system. In order to ensure
this, the open circuit voltage of an array needs to be calculated at the lowest expected local ambient
temperature, which can be determined using the following formula:
Max System Voltage
≥
N × 𝑉
𝑜𝑐
× [1 + 𝑇𝐶
𝑉𝑂𝐶
× (𝑇
𝑚𝑖𝑛
− 25)]
where
N
Number of modules in series
𝑉
𝑜𝑐
Open circuit voltage (refer to product label or data sheet)
𝑇𝐶
𝑉𝑂𝐶
Thermal coefficient of open circuit voltage (refer to data sheet)
𝑇
𝑚𝑖𝑛
The lowest expected environment temperature
The number of modules that can be connected shall be determined by a qualified institution or person
in accordance with the design specifications of the photovoltaic system and the local electrical design
specifications. The calculation formula recommended by Trina Solar shall be for reference only.
Every module is provided with two standard output cables, and each terminated with a plug-and-play
connector. All wiring and electrical connections must be installed in accordance with the electrical
design and construction specifications, procedures and regulations at the place of installation.
The minimum and maximum outer diameters of the cable are 5 to 7 mm (0. 20 to 0.28 in).
For wiring connections, please use standard PV copper wires with a cross-section area of at least 4
mm
2
(12 AWG), and should be light-resistant and temperature-resistant at a minimum of 90 °C.
Do not bend the cables less than 43 mm (1.69 inch) radius. PV cables will be damaged if bending
radius less than 43 mm.
Figure 4: The correct routing and minimum bending radius of cables.
