© 2022 Hoymiles Power Electronics Inc. All rights reserved.
18
Single-phase Microinverter HMS-350/400/450/500-1T-NA
143
Grid
Grid undervoltage
1. If the alarm occurs occasionally, the grid voltage may be just
abnormal temporarily. The microinverter can automatically
recover after grid voltage becomes normal.
2. If the alarm occurs frequently, check whether the grid
voltage is within the acceptable range. If not, contact the local
power operator or change the grid undervoltage protection
limit in the grid profile via Hoymiles monitoring system with
the consent of the local power operator.
3. If the fault still exists, check the AC switch or AC wiring.
144
Grid
Grid overfrequency
1. If the alarm occurs occasionally, the grid frequency may be
just abnormal temporarily. The microinverter can automatically
recover after grid frequency becomes normal.
2. If the alarm occurs frequently, check whether the grid
frequency is within the acceptable range. If not, contact the local
power operator or change the grid overfrequency protection
limit via Hoymiles monitoring system with the consent of the
local power operator.
145
Grid
Grid underfrequency
1. If the alarm occurs occasionally, the grid frequency may be
just abnormal temporarily. The microinverter can automatically
recover after grid frequency becomes normal.
2. If the alarm occurs frequently, check whether the grid
frequency is within the acceptable range. If not, contact the local
power operator or change the grid underfrequency protection
limit via Hoymiles monitoring system with the consent of the
local power operator.
146
Grid
Rapid grid frequency change
rate
1. If the alarm occurs occasionally, the grid frequency may be
just abnormal temporarily. The microinverter can automatically
recover after grid frequency becomes normal.
2. If the alarm occurs frequently, check whether the grid
frequency change rate is within the acceptable range. If not,
contact the local power operator or change the grid frequency
change rate limit in the grid profile in the grid profile via
Hoymiles monitoring system with the consent of the local
power operator.
147
Grid
Power grid outage
Please check whether the AC switch, branch breaker and AC
wiring is normal.
148
Grid
Grid disconnection
Please check whether the AC switch, branch breaker and AC
wiring is normal.
149
Grid
Island detected
1. If the alarm occurs occasionally, the grid frequency may be
just abnormal temporarily. The microinverter can automatically
recover after grid voltage becomes 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 or happens on only several
microinverters, please contact your dealer or Hoymiles technical
support.
205
MPPT-A
Input overvoltage
1. Please make sure that the PV module open-circuit voltage is
less than or equal to the maximum input voltage.
2. If the PV module open-circuit voltage is within the normal
range, contact your dealer or Hoymiles technical support team.
207
MPPT-A
Input undervoltage
1. Please make sure that the PV module open-circuit voltage is
not lower than minimum input voltage.
2. If the PV module open-circuit voltage is within the normal
range, contact your dealer or Hoymiles technical support team.
209
PV-1
No input
1. Please confirm whether this port is connected to the PV
module.
2. If the PV module is connected, please check the DC cable
connection between this port and the PV module.
