Losing access to your solar inverter's installer settings is a common headache, especially if your original installer is no longer available. Fortunately, Huawei has built-in safety procedures to let you regain control.
If your inverter is connected to the internet via a SmartLogger or 4G dongle, Huawei’s cloud may override the local password. huawei+sun2000+reset+installer+password+work
The most reliable way to reset the installer password involves a rhythmic cycling of the AC and DC switches Losing access to your solar inverter's installer settings