3.
Disconnect and isolate. (Not all disconnectors provide sufficient isolation against voltage
surges.). See instructions in section,
Disconnecting the inverter from all possible
.
4.
Protect any other energized parts in the work location against contact.
5.
Open the breaker and switches of the auxiliary service board.
6.
Open the main circuit breaker of the auxiliary service transformer, lock and add warning
notices.
7.
Disconnect the MV switchgear (V-module). See instructions in section
the MV switchgear (V-module) (page 14)
.
8.
Check that the inverter is dead. Make sure the voltage between the following terminals
and the grounding (PE) busbar is close to 0 V.
•
inverter AC output terminals (L1, L2, L3)
•
inverter power module UDC+ and UDC- terminals
•
DC input terminals DC+ and DC-
9.
After you disconnect the inverter, wait for at least five minutes to let the intermediate
circuit capacitors discharge before you continue.
10. Check that all shrouds/screens are in place except the one that prevents access to the
parts that you must work on currently.
11. Make sure you are not near to any live parts while working. Disconnect the live circuits
or protect with shrouds/screens.
12. Temporarily ground inverter 1 or inverter 2, AC and DC sides. Connect the AC and DC
busbars (in both DC sections) to PE with a temporary grounding tool.
13. Issue a work permit.
Disconnecting the inverter from all possible sources
To disconnect the inverter from all possible sources, such as AC & DC supply, external
auxiliary power, etc., follow below steps:
1.
Disconnect the inverter from the AC supply (normally a disconnector or a breaker on
the HV side of the main transformer), because the optional AC disconnectors or breakers
of the inverter do not remove the voltage from the AC outside busbars of the inverter.
2.
Disconnect the inverter from the DC power supply (usually the DC circuit breakers of
the solar array junction boxes or the DC combiner box), because the optional DC
disconnectors do not remove the voltage from the inverter input busbars or fuses.
3.
Disconnect the following optional devices:
Option code
Devices
1Q4 , 2Q4
AC main disconnection devices (AC breakers or AC switch disconnectors) of
all power units
1Q1, 2Q1
DC disconnectors of all the power sections
1Q10, 2Q10
Auxiliary power disconnectors of all the power sections
0Q12
3-phase output disconnector
0F11, 0F13)
1-phase output circuit breakers
If the inverter is supplied from external auxiliary power, disconnect also that.
4.
Make sure that reconnection is not possible. Lock all disconnectors in the open position
and attach warning notices. Lock and tag.
Safety instructions 13
