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000972AG
8 - Maintenance
The below picture represents the expected status of the switches in the
plant after the switching operations have been completed.
PV Strings
Internal DC
Switches
Internal AC
Switch
(if present)
Unit under service
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
Inverter 2
Power
Module
Wiring
Box
Inverter 3
Power
Module
Wiring
Box
External DC
Switch
(if present)
OPEN+LOTO
External DC
Switch
(If present)
OPEN
+
LOTO
OPEN
+
LOTO
Inverter 1
8. Remove the DC quick fit connectors
16
from wiring box
02
•
Using the current clamp check the absence of current on DC side,
measurement each positive and negative DC input string cables (check
the correct setting of the current sensor).
•
Remove all quick fit DC connectors
16
(PV Connectors) from the wiring
box
02
, using the dedicated disconnect tool. To avoid mechanical
interferences, use a cable tie to collect the disconnected cables.
After the intervention, before reconnecting the quick-fit DC connectors in
their counterparts, make sure about the followings (for each connection):
Checks related to the inverter:
For each input channel, verify the absence of short circuits between:
•
positive and negative terminals
•
positive and ground (PE) terminals
•
negattive and ground (PE) terminals
The test must be performed using multimeter (set to measure
Ohm) by placing the multimeter’s test point inside the inverter DC
connectors, in the same points where the quick-fit DC connectors
(coming from the strings) shall be reconnected.