© 2021 Hoymiles Power Electronics Inc. All rights reserved.
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Single-phase Microinverter User Manual
6.4 On-site Inspection (for qualified installer only)
To troubleshoot an inoperable microinverter, follow the steps mentioned below.
1
Verify that the utility voltage and frequency are within ranges shown in the Technical Data
appendix of this microinverter.
2
Check the connection to the utility grid. Verify that the utility power is present at the
microinverter in question by removing AC, then DC power. Never disconnect the DC wires
while the microinverter is producing power. Re-connect the DC module connectors and
watch for five short LED flashes.
3
Check the AC branch circuit interconnection between all the microinverters. Verify that each
microinverter is energized by the utility grid as described in the previous step.
4
Make sure that any AC breakers are functioning properly and are closed.
5
Check the DC connections between the microinverter and the PV module.
6
Verify that the PV module DC voltage is within the allowable range shown in the Technical
Data appendix of this manual.
7
If the problem persists, please call Hoymiles customer support.
Do not try to repair the microinverter. If troubleshooting fails, please return it to the factory
for replacement.
6.5 Routine Maintenance
1. Only authorized personnel are allowed to carry out the maintenance operations, and such personnel are
responsible for reporting any anomalies.
2. Always use the personal protective equipment provided by the employer when carrying out maintenance.
3. During normal operation, check that the environmental and logistical conditions are correct. Make sure
that these conditions have not changed over time and that the equipment is not exposed to adverse
weather conditions and has not been covered with foreign bodies.
4. DO NOT use the equipment if any problems are found, and restore the proper conditions after resolving
the problems.
5. Conduct an annual inspection of the various components, and clean the equipment with a vacuum cleaner
or special brushes.
Do not attempt to dismantle the microinverter or make any internal repairs! In order to preserve the
integrity of safety and insulation, the microinverters are not designed to allow internal repairs!
The AC output wiring harness (AC drop cable on the microinverter) cannot be replaced. If the cord is
damaged, the equipment should be scrapped.
Maintenance operations must be carried out with the equipment disconnected from the grid (grid
power switch on) and the PV modules obscured or isolated, unless otherwise indicated.
For cleaning, do not use rags made of filamentary materials or corrosive products that may corrode
parts of the equipment or generate electrostatic charges.
Avoid temporary repairs. All repairs should be carried out by using only genuine spare parts.
If all microinverters connect to the DTU-Pro, the DTU can limit the output power imbalance of all
microinverters between phases to below 3.68 kW if required. Please refer to the “Hoymiles Technical
Note Limit Phase Balance” for more details.
