The inverter refuses a parameter change and logs an event saying the grid parameters cannot be changed or are locked, or that a parameter setting failed. On SMA string inverters this shows up as event 29004, 9003 or 9005 in the event log or user interface. Event 9005 can mean three things: the rotary switch position for the country setting is not programmed, the parameters are protected, or the DC input voltage is too low to run the main computer. Event 9003 means the grid parameters are now locked, so you must log in with the SMA Grid Guard code before you can change them. If the Grid Guard code you enter is wrong, the parameters stay protected and the change is still rejected. When a single parameter setting fails, check that the new value is within the allowed thresholds, then try the change again. Check first that the country data set is configured correctly, that the Grid Guard code has been entered, and that there is enough DC voltage, shown by the green LED glowing or flashing.
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- sentence 2: support check: partial - Events 29004, 9003 and 9005 are in the passages, but the passages don't say they appear in the 'user interface' or specifically for string inverters beyond the 9005 article tag.
- sentence 7: support check: partial - The corrective measures list these three checks, but the passage doesn't say to check them 'first' or in any order.
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