ABB TRIO-20.0/27.6-TL-OUTD

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000041AG
7 - Operation
Checking the polarity of the strings (models S2F and S2X only)
Inside the wiring box
02
installed in inverter models S2F and S2X there
are two boards on which the string fuses are installed
22
.
The board that is positioned horizontally at the bottom of the wiring box
02
contains the safety fuses on the positive poles of the strings con-
nected in input, whereas the board that is installed vertically houses the
negative string fuses.
The string safety fuses are installed inside special positioners that allow
easy installation/removal, as well as providing protection from involuntary
contact while the inverter is being installed.
“Strings self-test” procedure
Automatic testing of the strings polarity is carried out using the following
procedure.
1. Before connecting the inverter input strings, remove all the fuses pre-
sent on the board that is installed vertically (negative string fuses) except
for the rst one on the left, i.e. the one relating to input 1A.
Refer to the specic replacement procedure in the manual for information on the removal/
installation procedure.
Once all the input strings foreseen have been connected, this operation
enables the inverter to be switched on using input string 1A only, so as
to check the polarity of all the other strings by reading the input voltages.
2. Connect all the strings foreseen by the project to the inverter
3. Turn the AC+DC Disconnect switch
14
to ON to supply the inverter
with the both the grid voltage and the voltages from the PV generator
strings.
- If the voltage from the only input string connected to the inverter is suf-
cient to switch the inverter on, but the display remains completely blank,
then the polarity of the string connected is reversed. Open the disconnect
switch and disconnect the string, change the polarity by reversing the
connectors, connect the string to the inverter again and close the AC+DC
disconnect switch
14
.
- If the voltage from the only input string connected to the inverter is suf-
cient to switch the inverter on, the display will light up.
1422
+
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14
-S2X