clean and dry.
Product can be irreparably damaged if an array string is connected in reverse polarity to another. Always verify the
voltage and polarity of each individual string before making a parallel connection. If you measure a reversed
polarity or a difference of more than 10V between strings then check the string configuration before making the
connection.
Trina Solar modules are provided with stranded copper cables with a cross sectional area of 4mm
²
which are rated
for 1000Vdc, 90°C and are UV resistant. All other cables used to connect the DC system should have a similar (or
better) specification. Trina Solar recommend that all cables are run in appropriate conduits and sited away from
areas prone to water collection.
The maximum voltage of the system must be less than the maximum certified voltage (1000V typically) and the
maximum input voltage of the inverter and of the other electrical devices installed in the system. To ensure that this
is the case, the open circuit voltage of the array string needs to be calculated at the lowest expected ambient
temperature for the location. This can be done using the following formula.
System voltage = N * Voc * [1 + TCvoc x (25 - Tmin)]
Where
N No modules in series
Voc
Open circuit voltage of each module (refer to product label or data sheet)
TCvoc
Thermal coefficient of open circuit voltage for the module (refer to table (add))
Tmin
Minimum ambient temperature
The minimum and maximum outer diameters of the cable are 5 to 7mm
2
.
For field connections, use at least 4 mm
2
copper wires insulated for a minimum of 90°C and sunlight resistance with
insulation designated as PV Wire.
The minimum bending radius cables should be 43mm.
7.
ELECTRICAL CONFIGURATION
Photovoltaic (electric) systems operate automatically and require very little day-to-day supervision. The solar array
generates DC electricity whenever light falls on it similarly the inverter automatically turns ON as soon as there is
sufficient energy from the solar array to efficiently convert this into grid quality AC power.
*Caution:
The module is rated to operate at potentially lethal DC voltages which have the potential can cause severe
electrical shock, arcing and fire hazards. Whilst some solar modules, manufactured by Trina Solar, are certified to
operate up to 1000V dc always check the module label to confirm the actual rating of your product before making
connections.
Always use a suitably rated isolator (DC switch) to interrupt the current flow before disconnecting the connectors.
7.1.
FUSING
When fuses are fitted they should be rated for the maximum DC voltage and connected in each, non-grounded pole
of the array (i.e. if the system is not grounded then fuses should be connected in both the positive and negative
poles).
The maximum rating of a fuse connected in series with an array string is typically 15A but the actual module
specific rating can be found on the product label and in the product datasheet.
This fuse rating value also corresponds to the maximum reverse current that a module can withstand (when one
string is shaded then the other parallel strings of modules will be loaded by the shaded string and current will flow)
and therefore impacts the number of strings in parallel.
7.2.
INVERTER SELETION AND COMPATIBILITY
When installed in systems governed by IEC regulations, Trina Solar modules normally do not need to be
electronically connected to earth and therefore can be operated together with either galvanically isolated (with
transformer) and transformerless inverters.
Potential Induced Degradation (PID) is sometimes observed in PV modules due to a combination of high humidity,
high temperature and high voltage. PID is most likely to cause degradation under the following conditions:
a) Installations in the warm and humid climates
Incorrect Routing of cable
Correct Routing of cable
5
