Hybrid Inverter User Manual
© 2022 Hoymiles Power Electronics Inc. All rights reserved.
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4. Troubleshooting
When the system is in alarm, please log into the S-Miles Cloud APP to review. The possible causes and their
troubleshooting are detailed in the following table:
Display
Possible Cause
Handling Suggestions
Grid
Overvoltage
The grid voltage is higher than
the permissible range.
Generally, the inverter will reconnect to the grid after the
grid recovers. If the alarm occurs frequently:
1. Make sure the safety country of the inverter is set
correctly.
2. Make sure that the grid voltage in your area is stable and
within the normal range.
3. Check whether the cross-sectional area of the AC cable
meets the requirement.
4. If the alarm persists, contact Hoymiles technical support
team.
Grid
Undervoltage
Undervoltage
grid voltage is lower than the
permissible range.
Generally, the inverter will reconnect to the grid after the
grid recovers. If the alarm occurs frequently:
1. Make sure the safety country of the inverter is set
correctly.
2. Make sure that the grid voltage in your area is stable and
within the normal range.
3. Check whether the AC cable is firmly in place.
4. If the alarm persists, please contact Hoymiles technical
support team.
Grid
Overfrequency
The grid frequency is higher than
the permissible range.
Generally, the inverter will reconnect to the grid after the
grid recovers. If the alarm occurs frequently:
1. Make sure the safety country of the inverter is set
correctly.
2. Make sure that the grid frequency in your area is stable
and within the normal range.
3. If the alarm persists, please contact Hoymiles technical
support team.
Grid
Underfrequency
The grid frequency is lower than
the permissible range.
No Grid
The inverter detects that there is
no grid connected.
Generally, the inverter will reconnect to the grid after the
grid recovers. If the alarm occurs frequently:
1. Check whether the grid supply is reliably.
2. Check whether the AC cable is firmly in place.
3. Check whether the AC cable is correctly connected.
4. Check whether the AC circuit breaker is disconnected.
5. If the alarm persists, contact Hoymiles technical support
team.
Residual Current
Fault
The residual leakage current is
too high.
1. The alarm can be caused by high ambient humidity, and
the inverter will reconnect to the grid after the environment
is improved.
2. If the environment is normal, check whether the AC and
DC cables are well insulated.
3. If the alarm persists, contact Hoymiles technical support
team.
PV Reverse
Connection
The inverter detects that
the PV strings are reversely
connected.
1. Check whether the corresponding string is of reverse
polarity. If so, disconnect the DC switch and adjust the
polarity when the string current drops below 0.5A.
2. If the alarm persists, contact Hoymiles technical support
team.
PV Undervoltage
The PV voltage is lower than
the permissible range.
1. Check whether the DC cable is firmly in place.
2. Check whether there is a PV module shaded. If so, remove
the shade and ensure the PV module is clean.
3. Check whether the PV module is in abnormal aging.
4. If the alarm persists, contact Hoymiles technical.
PV Overvoltage
The PV voltage is higher than the
permissible range.
1. Check the specification and numbers of corresponding
string PV modules.
2. If the alarm persists, contact Hoymiles technical support
team.
