Equipment
- Inverter: Solis 11.4kW
- Utility Service: Split-phase residential
- Monitoring: Solis Cloud
Alarm Code 1011
Displayed Message
Grid voltage out of range
What this alarm means
Solis inverters use factory-locked voltage thresholds:
- Warning threshold: 211 V
- Shutdown threshold: 120 V
If voltage falls below 120 V, the inverter shuts down to protect itself.
What We Found
- Inverter was reading 117 V at its AC terminals
- DC input from the solar array was stable
- Multimeter confirmed low voltage at the inverter output
This initially appeared to be a utility grid issue.
Root Cause Identified
After coordinating with Solis support to temporarily allow the inverter to remain online for troubleshooting, we discovered:
- Loose conductor tap connections at the inverter’s AC tie-in to the utility line
- Evidence of arcing at the taps
These loose connections caused:
- Increased resistance
- Localized voltage drop
- False low-voltage readings at the inverter
Solution Implemented
- Safely shut down the system
- Retorqued conductor taps using:
- 5/16" hex wrench
- Channel locks for final secure seating
- Restored power
Results immediately after repair
- Voltage returned to ~240 V
- Arcing eliminated
- Alarm Code 1011 cleared
Final Restoration Steps
- Reset dataloggers
- Reconnected inverter to Wi-Fi
- Remotely toggled inverter ON via:
- Solis App → Device → Inverter Control
Final Result
- System fully operational
- Normal voltage readings restored
- No inverter replacement required
Key Takeaway
Alarm Code 1011 is often caused by connection issues, not utility voltage. Always inspect and torque AC taps before escalating to the utility or replacing equipment.
