© 2021 Hoymiles Power Electronics Inc. All rights reserved.
15
Single-phase Microinverter User Manual
141
Grid overvoltage
1. If the alarm occurs accidentally, the grid voltage may be temporarily
abnormal. The microinverter will automatically recover after grid
voltage returns to normal.
2. If the alarm occurs frequently, check whether the grid voltage is
within the acceptable range. If it is not, contact the local power
operator or change the grid overvoltage protection limit via the
Hoymiles Monitoring System after obtaining the consent of the local
power operator.
142
Grid overvoltage (10-
minute average value)
1. If the alarm occurs accidentally, the grid voltage may be temporarily
abnormal. The microinverter will automatically recover after grid
voltage returns to normal.
2. If the alarm occurs frequently, check whether the grid voltage is
within the acceptable range. If it is not, contact the local power
operator or change the grid overvoltage protection limit via the
Hoymiles Monitoring System after obtaining the consent of the local
power operator.
143
Grid undervoltage
1. If the alarm occurs accidentally, the grid voltage may be temporarily
abnormal. The microinverter will automatically recover after grid
voltage returns to normal.
2. If the alarm occurs frequently, check whether the grid voltage is
within the acceptable range. If it is not, contact the local power
operator or change the grid undervoltage protection limit via the
Hoymiles Monitoring System after obtaining the consent of the local
power operator.
3. If the fault still exists, check the AC switch or AC wiring.
144
Grid overfrequency
1. If the alarm occurs accidentally, the grid frequency may be
temporarily abnormal. The microinverter will automatically recover
after grid frequency returns to normal.
2. If the alarm occurs frequently, check whether the grid frequency
is within the acceptable range. If it is not, contact the local power
operator or change the grid overfrequency protection limit via the
Hoymiles Monitoring System after obtaining the consent of the local
power operator.
145
Grid underfrequency
1. If the alarm occurs accidentally, the grid frequency may be
temporarily abnormal. The microinverter will automatically recover
after grid frequency returns to normal.
2. If the alarm occurs frequently, check whether the grid frequency
is within the acceptable range. If it is not, contact the local power
operator or change the grid underfrequency protection limit via the
Hoymiles Monitoring System after obtaining the consent of the local
power operator.
146
Rapid grid frequency
changes
1. If the alarm occurs accidentally, the grid frequency may be
temporarily abnormal. The microinverter will automatically recover
after grid frequency returns to normal.
2. If the alarm occurs frequently, check whether the grid frequency
change rate is within the acceptable range. If it is not, contact the
local power operator or change the grid frequency change rate limit
via the Hoymiles Monitoring System after obtaining the consent of
the local power operator.
147
Power grid outage
Please check whether there is a power grid outage.
148
Grid disconnection
Please check whether the AC switch or AC wiring functions normally.
149
Island detected
1. If the alarm occurs accidentally, the grid voltage may be temporarily
abnormal. The microinverter will automatically recover after grid
voltage returns to normal.
2. If the alarms occur frequently on all the microinverters in your
station, contact the local power operator to check whether there is a
grid island.
3. If the alarm still exists, contact your dealer or Hoymiles Technical
Service Center.
