Solahart Solahart390V2, Руководство по установке

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13
6 Electrical Installation
6.1
Electrical characteristics
The electrical characteristics are detailed in the PV
module product manual.
The rated values of electrical characteristics, including
I
sc
, V
oc
and P
mpp
, have some tolerance with the measured
values at standard condition: ±5% for I
sc
,
±3% for V
oc
and ±3% for P
mpp
. The standard test
condition refers to 1000W/m
2
, AM1.5 and cell
temperature at 25℃.
According to IEC and UL standards, the standard
maximum system voltage for the regular module series
is 1000V, the 1500V standard products are also
available according to the requirements. The IEC & UL
standard maximum system voltage for half-cell module
series is 1500V (except for BL &LV series PV modules).
The actual maximum voltage must be less than the
standard maximum system voltage and the maximum
output voltage of the inverter and other electrical
equipment installed in the system. The number of PV
modules connected in series should match the voltage
specification of the inverter. The total voltage generated
by PV modules in series should not be higher than the
maximum voltage allowed by the system.
To ensure the above requirements, the open-circuit
voltage of the string needs to be calculated at the
lowest expected ambient temperature at certain
location. This can be calculated using the following
formula:
Maximum system voltage≥N*
V
oc
*[1+ TC
voc
*(T
min
-25)]
Where:
N: number of PV modules in a single string
V
oc
: open-circuit voltage of each PV module (refer to
the PV module nameplate or product manual)
TC
voc
: temperature coefficient of PV module for open-
circuit voltage (refer to the PV module product manual)
T
min
: minimum ambient temperature.
！
ATTENTION

Under normal operating conditions, the output current
and/or voltage of the PV module may be higher than
the value under standard testing conditions. Therefore,
in PV system design, for example determining the rated
voltage of equipment, current carrying capacity of
wires and fuse and parameters associated with the
output power of PV modules, the corresponding short-
circuit current and open-circuit voltage should be
applied with a safety factor of 1.25. The number of PV
modules connected in series should match the voltage
specification of the inverter. The total voltage
generated by the PV modules connected in series
cannot be higher than the maximum voltage allowed by
the system.

According to the National Electrical Code 690.8, the
parameters need to be multiplied by an additional
125% (80% derating) factor, i.e. the parameters
including the optimum operating current and voltage
at standard test condition (STC) needs to be multiplied
by the square of 1.25 when determining voltage ratings,
conductor capacities, fuse ratings, and control sizes for
PV output.