
- 146 -
000972AG
8 - Maintenance
5. Operations on External DC switches (if present)
In case of absence of External DC disconnect device skip this step.
The diagram below represents a possible arrangement of the PV plant.
Depending on the design choices made by the developer of the plant
some of the devices could not be present. Identify the external DC
switch(es) in the plant with the support of the plant manager.
•
Open the external DC disconnect switch (in blue in the picture) outside
the inverter (IEC 60364-7-712.536.2.2)
PV Strings
Internal DC
Switches
Internal AC
Switch
(if present)
Power
Module
Wiring
Box
OPEN+LOTO
PV Strings
External DC
Switch
(if present)
Internal DC
Switches
Internal AC
Switch
(if present)
External LV
AC Switch
External Main LV
AC Switch
External LV
AC Switch
LV Distriubution
Panel
MW Switch
PV Strings
Internal DC
Switches
Internal AC
Switch
(if present)
External LV
AC Switch
LV/MW
Transformer
Power
Module
Wiring
Box
Power
Module
Wiring
Box
External DC
Switch
(if present)
OPEN+LOTO
External DC
Switch
(If present)
Unit under service
Inverter 2
Inverter 3
Inverter 1
•
Affix padlocks to prevent operation onto any external DC disconnect
device. Affix designated tags (LOTO procedure).
Identification of the external switch may require the cooperation of the plant manager and it
must be included in the switching plan defined during the preparation of the work.
•
Check on the status LEDs
08
the shutdown command has been carried
out (Missing DC voltage status):
All LEDs OFF
.
The time needed for the complete shut-down of the LEDs depends by the input voltage of the
inverter. The complete shut-down of the LEDs may require some minutes.