3401 SMA — Grid Fault — Frequency/Voltage Out of Range
At a glance
- Severity
- FAULT STOP
- Domain
- INVERTER_FV
- Reference standard
- CEI 0-21 (59.S1, 59.S2, 27.S1, 27.S2, 81>.S1) / IEC 62116
- Product / context
- Grid Overvoltage (Vac)
What it means
The inverter disconnects from the grid due to voltage or frequency limits exceeding the thresholds defined by the CEI 0-21 standard. The interface protections (59.S1, 59.S2, 27.S1, 27.S2, 81>.S1, 81<.S1) trip and the inverter enters a fault state, halting production.
Probable causes
- Grid voltage at the PCC out of range (typically > 253 V or < 195 V single-phase) due to issues on the MV/LV distribution network.
- Unstable grid frequency due to load shedding or distribution network fault.
- Grid impedance too high at the point of connection (undersized or excessively long connection cable).
- CEI 0-21 protection parameters incorrectly configured (thresholds or timing not compliant with CEI 0-21 Table 8).
- Interrupted neutral or intermittent contact on the AC line upstream of the inverter.
Where to start
Measure the grid voltage at the PCC (Point of Common Coupling) with a multimeter. Is the value within the 195-253 V (single-phase) or 340-440 V (three-phase) range?
Full guided diagnosis in the app
The diagnostic tree for this fault has 9 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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