Internal Measurement Comparison Error
SMA · SUNNY BOY 5000US-8000US Solar Inverter
What does MSD-FAC/MSD-Idif mean?
An internal measurement comparison error has occurred in the Sunny Boy SB50US-80US-IUS094030, indicating a significant discrepancy between the values measured by the BFR (Betriebsführungsrechner) and SRR (Stromregelungsrechner) processors. This suggests an inconsistency in internal data acquisition related to frequency (FAC) or differential current (Idif).
Common Causes
- Discrepancy between BFR and SRR measured values for frequency (FAC).
- Discrepancy between BFR and SRR measured values for differential current (Idif).
Repair Steps & Checklist
Click steps to track your progress.
- 1
Measure AC grid voltage and frequency at the inverter's AC input terminals to confirm stability and compliance with specifications.
- 2
Inspect all DC input and AC output wiring, including ground connections, for proper termination, damage, or corrosion.
- 3
Verify all grid-related and safety-relevant parameters (e.g., frequency limits, voltage thresholds, ground fault settings) in the inverter's configuration.
- 4
Perform a controlled power cycle of the inverter (disconnect AC and DC, wait 5 min, reconnect) to clear potential transient errors.
- 5
Check the inverter's diagnostic logs and real-time data for specific measurement discrepancies between internal processors (BFR/SRR) if accessible via the user interface or service tool.