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Self test
The self test is mandatory for operation of inverters in Italy.
Function
The prerequisites for performing the self test are as follows:
• The country Italy was selected during initial commissioning.
• 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 (4 test phases, duration of approx. 8 minutes). The following applies:
• 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.
• When the switch-off threshold reaches the actual grid voltage/frequency then the inverter stores
this information.
• The data is shown on the display as follows:
– The current values of the first test phase are displayed first; see Fig. 13.
– 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 message
must be displayed and confirmed.
• If the self test conditions are not satisfied, one of the messages listed in Tab. 9 is displayed.
• 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 discon-
nected 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.
Fig. 13: Self test – display of the test results
Operation
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✔ The country Italy is set in the inverter to be tested.
1. Check the country setting via Information/System
2. Select Self test in the main menu. The dialogue
3. Press and hold SET for 1 second. The self test starts.
Upper / lower limit value according to the country set-
ting
Measured actual grid voltage / frequency
Switch-off threshold (changed in steps)
Switch-off time = time between the following events:
Switch-off threshold reaches the actual grid voltage/
–
frequency
The inverter disconnects itself from the grid
–
info in the main menu as required.
shown at the left is displayed.
EN
77