Activating and Setting String-Failure Detection
Qualified person
If you would like to use the string-failure detection, you will have to activate it.
You have the option of combining inputs with the same properties (e.g. shading, alignment or module type) in a group. A total of 3 groups are available. At least 2 inputs must be assigned per group.
You must set the sensitivity and tolerance for string-failure detection. You must also set the minimum time for which the tolerance must be exceeded before the inverter reports an event.
You can also set the activation threshold for string-failure detection to avoid an erroneous event message. In systems with a very inhomogeneous alignment of the PV modules, events of too low DC voltage or too low DC current can occur relatively frequently. If you increase the activation threshold, make sure that the string-failure detection only becomes active when there is sufficient DC power. In this way, you avoid erroneous event messages under unfavorable irradiation conditions.
You can carry out the activation and setting of the string-failure detection via the device parameters or using the installation assistant.
The activation threshold for the string-failure detection can only be set via the device parameters. The activation threshold is set to 20% of the inverter's nominal power by default.
Settings via device parameters
In the following table, you will find all parameters that are needed to activate and set the string-failure detection.
Object name | Parameter | Display group | Settings |
|---|---|---|---|
Operation.StrFltDet.OpMod | Operating mode of the string-failure detection | DC side > Operation > String-failure detection > General operating mode |
|
Operation.StrFltDet.ChGrp | String comparison group for string-failure detection | DC side > Operation > String-failure detection > Comparison group |
|
Operation.StrFltDet.SnsLvl | Sensitivity of string-failure detection | DC side > Operation > String-failure detection > Sensitivity of the sensors |
|
Operation.StrFltDet.Tol | Tolerance of string-failure detection | DC side > Operation > String-failure detection > Tolerance |
|
Operation.StrFltDet.WrnTm | Time until string-failure detection warning | DC side > Operation > String-failure detection > Time until warning |
|
Operation.StrFltDet.WMinNom | Activation threshold for string-failure detection1) | DC side > Operation > String-failure detection > Nominal AC power |
|
1) Parameter can exclusively be set via the device parameters.
Procedure:
- Activate the user interface of the inverter.
- Log into the user interface as an Installer.
- Call up the menu Device parameters.
- Click on [Edit parameters].
- Expand the display group that contains the parameter.
- Set the parameter.
- Select [Save all] to save the settings.
Configuration with the help of the installation assistant
Procedure:
- Open the user interface ( > Establishing a connection to the user interface).
- Log into the user interface as an Installer.
- On the right-hand side of the menu bar, select the menu User Settings ( > Start Page Design of the User Interface).
- In the context menu, select [Starting the installation assistant].
- Select [Save and next] until you reach the String configuration step.
- Activate string-failure detection and making settings.
- Select [Save and next].