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Use appropriate safety equipment (insulated tools, dielectric gloves and shoes, etc) approved for use
on electrical installations.
4.2 Configuration
Under normal conditions, a photovoltaic module is likely to experience conditions that produce more
current and/or voltage than reported at Standard Test Conditions (STC: 1000 W/m2, AM 1.5, and 25°C
cell temperature) or Bifacial Standard Test Conditions (BSTC: 1167 W/m2, AM 1.5, and 25°C cell
temperature). The short-circuit current (ISC) should be multiplied by a factor of 1.25 and the open-
circuit voltage (VOC) should be multiplied by a factor of up to 1.25 based on the lowest and highest
ambient temperature recorded for the installation location when determining component voltage
ratings, conductor current ratings, fuse sizes, and size of controls connected to the PV output.
Voltages are additive when PV modules are connected directly in series, and module currents are
additive when PV modules are connected directly in parallel. PV modules with different electrical
characteristics must not be connected directly in series. The use of suitable third-party electronic
devices connected to PV modules may enable different electrical connections and must be installed
according to the manufacturer’s specified instructions.
The maximum voltage of serial interconnection of the modules must be less than the maximum
certified module‘s system voltage. Also, the maximum input voltage of the inverter and of the other
electrical devices in the system must be taken into account. The open circuit voltage of the array
string needs to be calculated at the lowest expected ambient temperature for the location. The
maximal system voltage for module is indicated in the modules datasheet.
Accordingly for Pro or Bifacial series modules, the values of ISC and VOC under STC or BSTC marked
on this 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. In the USA,
refer to Section 690-8 of the National Electrical Code (NEC) for an additional multiplying factor of 125
percent (80 percent de-rating) which may be applicable.
