Date: July 18, 2025
System: Solis 11.4kW Inverter
Issue: Alarm Code 1011 – Grid Voltage Out of Range
The Problem
One of our customers reported that their Solis 11.4kW inverter had stopped producing and was displaying Alarm Code 1011, which means the inverter is detecting grid voltage outside the allowed range.
What the Code Means
Solis inverters have preset grid voltage thresholds that cannot be changed in the field:
- Threshold 1: 211V (warning)
- Threshold 2: 120V (shutdown)
In this case, the inverter was seeing 117V — below the shutdown threshold — triggering the alarm and stopping production.
Step-by-Step Troubleshooting
Step 1: Confirm Grid Voltage
We confirmed with a multimeter that the inverter was reading 117V at its AC output. The DC side remained stable with no issues from the array.
Step 2: Temporary Override
We reached out to Solis support and requested a temporary adjustment to allow the inverter to operate below 117V so we could troubleshoot.
Step 3: Inspect for Physical Issues
Once the inverter remained online, we observed arcing at the conductor taps connecting the inverter output to the main utility line. The culprit: loose tap connections causing:
- Increased resistance
- Local voltage drop
- False readings of low grid voltage
Step 4: Fix the Connection
We shut down the system and tightened the conductor taps using a 5/16" hex wrench and a channel lock to ensure a firm, secure connection.
After restoring the connection:
- Voltage returned to normal (~240V)
- Arcing stopped
- Alarm cleared
Final Steps to Restore Operation
- Reset the dataloggers
- Reconnect to Wi-Fi
- In the Solis app, go to Device → Inverter Control
- Toggle the inverter switch from OFF to ON remotely
The system came back online and resumed normal power production.
Takeaway
Loose or under-torqued tap connections can cause voltage drop and make your inverter think there’s a grid problem. If you see Alarm 1011, always inspect physical AC connections before assuming utility voltage is to blame.