301 GoodWe — MPPT Tracking Error
At a glance
- Severity
- WARNING
- Domain
- INVERTER_FV
- Reference standard
- IEC 62891 / IEC 61724-1
- Product / context
- PV Input Fault
What it means
The inverter fails to correctly track the Maximum Power Point (MPP) on one or more MPPT inputs. Production is lower than expected, with evident imbalances between MPPTs.
Probable causes
- Incorrect MPPT configuration: strings with different module counts connected to the same MPPT.
- Unbalanced strings due to different orientation, tilt, or partial shading across MPPTs.
- Partial shading on a single MPPT causing a double-knee IV curve.
- Defective or degraded modules (hot-spot, PID) altering the string characteristic curve.
- Short-circuited bypass diode on one of the string modules.
Where to start
Access the inverter monitoring and compare the instantaneous power and voltage of each MPPT. Is there a difference greater than 15% between MPPTs with the same string configuration?
Full guided diagnosis in the app
The diagnostic tree for this fault has 8 guided steps with measurements, checks and resolutions. You'll find it in ElectraIQ, one of the five IndexOS apps: free, works offline.
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