User manual
6 Self test
The self test is mandatory for operation of inverters in Italy.
Function
The prerequisites for performing the self test are as follows:
n The country
Italy
was selected during initial commissioning.
n The level of solar irradiation is high enough to ensure that the inverter can feed the grid.
During the self test, the inverter checks its switch-off behaviour with regard to too high / too low
grid voltage and frequency (6 test phases, duration of approx. 40 minutes). The following applies:
n In each phase of the self test, the inverter changes its switch-off threshold, step-by-step
upwards/downwards from the set lower/upper limit values.
n When the switch-off threshold reaches the actual grid voltage/frequency then the inverter
stores this information.
n The data is shown on the display as follows:
–
The current values of the
first
test phase are displayed first; see the following illustration.
– The values of the subsequent test phases are added below (initially hidden).
– If the self test succeeded then the message Self test passed is added below. The mes-
sage must be displayed and confirmed.
n If the self test conditions are not satisfied, one of the
Ä Messages of errors that prevent the
self test from running, p. 127
is displayed.
n If a measurement lies outside the required tolerance during the self test then the self test is
cancelled and the inverter displays the message Self test failed. The inverter remains dis-
connected from the grid (relay open, no feeding) until the self test is passed successfully.
Note
The data stored in the inverter can be read using a PC and the InverterSelftestProtocol software.
More information on this is provided in the StecaGrid Service_InverterSelftestProtocol manual and
at
www.stecasolar.com ⇒ PV grid connected ⇒ Software.
①
Lower / upper limit value according to the country setting
②
Measured actual grid voltage / frequency
③
Switch-off threshold (changed in steps)
④
Switch-off time = time between following events:
n Switch-off threshold reaches the actual grid voltage / fre-
quency
n The inverter disconnects itself from the grid
GB
747.431 | Z08 | 2014-01-31
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