© 2021 Hoymiles Power Electronics Inc. All rights reserved.
14
Single-phase Microinverter User Manual
6. Troubleshooting
This microinverter can only work with the new Hoymiles DTU (DTU-Pro, DTU-Lite and DTU-W100/DTU-G100)
with the following serial number.
Model
Serial Number
DTU-Pro
10F7xxxxxxxx
10F8xxxxxxxx
10FAxxxxxxxx
DTU-G100
10D2xxxxxxxx
DTU-W100
10D3xxxxxxxx
DTU-Lite
10D6xxxxxxxx
6.1 Troubleshooting List
Alarm Code
Alarm Name
Suggestion
121
Over temperature
protection
1. Check the ventilation and ambient temperature at the microinverter
installation position.
2. If the ventilation is poor or the ambient temperature exceeds the
limit, improve the ventilation and heat dissipation.
3. If both the ventilation and ambient temperature meet the
requirements, contact your dealer or Hoymiles Technical Service
Center.
125
Grid configuration
parameter error
1. Check if the grid configuration parameter is correct and upgrade
again.
2. If the fault still exists, contact your dealer or Hoymiles Technical
Service Center.
126
Software error code
126
1. If the alarm occurs accidentally and the microinverter can still
function normally, no special treatment is required.
2. If the alarm occurs frequently and cannot be restored, contact your
dealer or Hoymiles Technical Service Center.
127
Firmware error
1. Check if the firmware is correct and upgrade again.
2. Check the communication between the DTU and Hoymiles Monitoring
System, as well as the communication between the DTU and the
microinverter. Then try again.
3. If the fault still exists, contact your dealer or Hoymiles Technical
Service Center.
128
Software error code
128
1. If the alarm occurs accidentally and the microinverter can still
function normally, no special treatment is required.
2. If the alarm occurs frequently and cannot be restored, contact your
dealer or Hoymiles Technical Service Center.
129
Software error code
129
1. If the alarm occurs accidentally and the microinverter can still
function normally, no special treatment is required.
2. If the alarm occurs frequently and cannot be restored, contact your
dealer or Hoymiles Technical Service Center.
130
Offline
1. Please check if the microinverter works normally.
2. Check the communication status between the DTU and Hoymiles
Monitoring System, or between the DTU and the microinverter. Try to
make improvements if the communication is poor.
3. If the alarm occurs frequently and cannot be restored, contact your
dealer or Hoymiles Technical Service Center.
