When alarm 326 - 1 (Abnormal Grounding) alarm is generated the recommendations are the following:
- Check that the neutral wire or PGND cable properly connects to the inverter
- If the PV string output is grounded, check that the SUN2000 output side connects to an isolation transformer
Another reason exists, which is often overlooked, the Isolation setting of the inverter is chosen incorectly.
There are 3 possibilities:
- Input grounded, with TF (if the input is grounded (the plus or minus of the strings) it is mandatory to use an isolation transformer for the output in order to achieve galvanic separation)
- Input ungrounded, without TF (the input is ungrounded and the output is directly connected to the grid)
- Input ungrounded, with TF (the input is ungrouded and the output is connected to a step-up transformer)
Depending on the application scenario, the correct configuration must be chosen accordingly otherwise the 326 -1 alarm will be generated
This setting can be done using the SUN2000 App, SmartLogger or NetEco.
When using the SUN2000 App, login as Advanced user and go to: Settings - Grid Parameters - Isolation
When using SmartLogger, login as Advanced user and go to: Monitoring - Select inverter - Running Param. - Grid Parameters - Isolation
When using NetEco, go to: Monitor - Select inverter - Settings - Grid Parameters - Isolation
