Operation and installation manual
Page 72 of 82
(PVI-10.0/12.5-OUTD-xx Rev:1.2)
8
SPECIFICATIONS
8.1
Input values
WARNING:
the photovoltaic field and system wiring shall be set up so that
PV input voltage is lower than maximum limit, regardless of the model,
number and operating conditions of the chosen photovoltaic panels.
Since panel voltage also depends on operating temperature, choose the
number of panels for each string considering the minimum ambient
temperature foreseen for that specific area (see table A).
WARNING
: the inverter is equipped with a linear limit of output power,
according to input voltage, from 750 Vdc (100% power output) to 850 Vdc
(0% power output)
WARNING
: photovoltaic panels open-loop voltage depends on ambient
temperature (open-loop voltage increases when temperature decreases) and
you shall ensure that foreseen minimum temperature for the installation will
not make panels exceed maximum voltage limit of 850Vdc. The following
table is an example indicating the maximum voltage of each panel for typical
panels with 36, 48 and 72 cells, according to the temperature (assuming a
nominal open-loop voltage of 0.6Vdc per cell at 25°C and a temperature
coefficient of -0.0023V/°C. Thus, the table shows the maximum number of
panels that can be connected in series according to the minimum temperature
at which system will operate. Please contact panel manufacturer to find the
correct temperature coefficient of V
oc
before calculating maximum voltage of
the photovoltaic array.
