EN
42
5.5 Input connection (DC)
WARNING –
B
Check absence of any leakage to ground in the PV generator.
WARNING –
B
The input strings connected to an input channell must have the same installation conditions (number of panel sets,
panel type, orientation and tilt).
WARNING –
B
When the photovoltaic panels are exposed to sunlight they provide continuous DC voltage to the inverter. To avoid
risks of electrical shock, all wiring operations must be carried out with the DC disconnect switches (internal
(07)
and external to the
inverter) and external AC disconnect switches OFF.
WARNING –
B
The inverters referred to in this document are WITHOUT AN ISOLATION TRANSFORMER (transformerless). This
topology implies the use of isolated PV panels (IEC61730 Class A Rating) and the need to keep the PV array floating with respect to
ground: no terminal of the PV array must be connected to ground.
WARNING –
B
Comply with the maximum input current relating to the quick-fit connectors as indicated in the technical data.
WARNING –
B
The reverse polarity can cause severe damage and electric arc hazards! In case of reverse input strings do not
disconnect them while under load and do not turn the DC disconnect switches
(07)
to OFF position. Wait until input current are below
0.5A (when solar irradiance declines at night) and turn the DC disconnect switches
(07)
to OFF position, disconnect the DC input
quick fit connectors
(13)
and correct the wrong polarity of the string.
For the string connections it is necessary to use the DC input quick
fit connectors
(13)
, located on the bottom side of the inverter.
The input connectors are divided into 2 groups (one group for each
input channel). For each channell 2 pairs of quick fit connectors
are available.
Respect the Maximum DC input power for each MPPT as follow:
Model
IN1
IN2
PVS-10-TL
17A / 7.8kW
17A / 7.8kW
PVS-12.5-TL
18A / 8.3kW
18A / 8.3kW
PVS-15-TL
22A / 10kW
22A / 10kW
13
5.5.1 Preliminary operations to the connection
of the PV generator
WARNING –
B
In order to safely perform the preliminary
operations before the connection to the PV generator, the
connection of the ground protection cable to the inverter is
mandatory.
ATTENTION –
A
The installation must be performed by
qualified installers and/or licensed electricians in accordance
with the existing regulations in the country of installation and
in accordance of all safety rules for performing electrical
works. These activity is allowed ONLY with the appropriate
PPE for carrying out this check (overall resistant to electric
arc, dielectric helmet with visor, insulating gloves class 0,
Protective overglove in leather EN420 – EN388, Safety
shoes).
Checking the correct polarity of the strings
Using a voltmeter, check that the voltage of each string observes
the correct polarity.
ATTENTION –
A
The reverse polarity can cause severe
damage.
Checking of leakage to ground of the photovoltaic generator:
Measure the voltage present between positive and negative pole
of each string with respect to ground.
If a voltage is measured between an input pole and ground, it
may be that there is a low isolation resistance of the photovoltaic
generator and the installer will have to carry out a check to solve
the problem.
WARNING –
B
Do not connect the strings if a leakage to
ground has been detected, as the inverter might not connect
to the grid.
Refer to
“Verification of ground leakage”
paragraph on
this manual to know how to verify the leakage to ground of the
photovoltaic generator.
Checking of strings voltage:
Measure the voltage present between positive and negative pole
of each string.
If the open circuit voltage of the string is near the maximum value
accepted by the inverter, consider that low ambient temperatures
cause an increase in the string voltage (different according to the
photovoltaic module used). In this case it is necessary to carry
out a check of the sizing of the system and/or a check on the
connections of the modules of the system (e.g.: number of modules
in series higher than the design number).
ATTENTION –
A
Verify that the string voltage is the same in
all the strings that are connecting to the same input channel.
Voltage differences (of the strings connected in parallel)
could reduce performance.
ATTENTION –
A
Input voltages higher than the maximum
value accepted by the inverter (see technical data table) may
occur the damage of the inverter.
5.5.1.1 Installation procedure for quick-fit connectors
The model of connectors installed on your inverter must be
matched by the same model of the respective corresponding parts
to be used.
WARNING –
B
To avoid damage to the equipment, when
