Hoymiles HMT-1600-4T User manual

Open Energy for All
Three-phase Microinverter
HMT-1600-4T
HMT-1800-4T
HMT-2000-4T
USER MANUAL
Region: EMEA & APAC V202303 hoymiles.com

© 2023 Hoymiles Power Electronics Inc. All rights reserved. 2
Three-phase Microinverter HMT-1600/1800/2000-4T
About Microinverter
This system is composed of a group of microinverters that convert direct current (DC) into alternating
current (AC) and feed the power to the public grid. The system is designed for 4-in-1 microinverters,
i.e., one microinverter is connected with four PV modules.
Each microinverter works independently so as to guarantee the maximum power generation of
each PV module. This setup is highly exible and reliable as the system enables direct control of the
production of each PV module.
About the Manual
This manual contains important instructions for HMT-1600-4T/HMT-1800-4T/HMT-2000-4T
microinverters and users shall read in its entirety before installing or commissioning the equipment.
For safety reasons, only qualied technicians who have received training or demonstrate relevant
skills can install and maintain this microinverter under the guidance of this document.
Other Information
Product information is subject to change without notice. User manual will be updated regularly, so
please refer to Hoymiles ocial website at www.hoymiles.com for the latest version.

© 2023 Hoymiles Power Electronics Inc. All rights reserved. 3
Three-phase Microinverter HMT-1600/1800/2000-4T
1. Important Notes 4
1.1 Product Range 4
1.2 Target Group 4
1.3 Symbols Used 4
1.4 Radio Interference Statement 4
2. About Safety 5
2.1 Important Safety Instructions 5
2.2 Explanation of Symbols 6
3. About Product 7
3.1 About PV Microinverter System 7
3.2 About Microinverter 7
3.3 About 4-in-1 Unit 8
3.4 About Sub-1G Technology 8
3.5 Highlights 8
3.6 Terminals Introduction 9
3.7 Dimensions (mm) 9
4. Installation Preparation 10
4.1 Position and Space Required 10
4.2 Connecting Multiple PV Modules to Microinverter 10
4.3 Installation Tools 11
4.4 AC Branch Circuit Capacity 11
4.5 Precautions 12
5. Microinverter Installation 13
5.1 Accessories 13
5.2 Installation Steps 13
6. Troubleshooting 17
6.1 Troubleshooting List 17
6.2 LED Indicator Status 20
6.3 On-site Inspection (For qualied installers only) 21
6.4 Routine Maintenance 21
6.5 Microinverter Replacement 22
7. Decommission 23
7.1 Decommission 23
7.2 Storage and Transportation 23
7.3 Disposal 23
8. Technical Data 24
9. Appendix 1: 25
9.1 Installation Map 25
10. Appendix 2: 26
10.1 WIRING DIAGRAM – 230VAC / 400VAC THREE PHASE: 26
CONTENTS

© 2023 Hoymiles Power Electronics Inc. All rights reserved. 4
Three-phase Microinverter HMT-1600/1800/2000-4T
1. Important Notes
1.1 Product Range
This manual describes the assembly, installation, commissioning, maintenance and troubleshooting of the
following models of Hoymiles Microinverter:
· HMT-1600-4T
· HMT-1800- 4T
· HMT-2000-4T
Note:
• “1600” means 1600 W. “1800” means 1800 W, “2000” means 2000 W.
• HMT-1600/1800/2000-4T is only compatible with Hoymiles gateway DTU-Pro-S and DTU-Lite-S.
1.2 Target Group
This manual is only for qualied technicians. For safety purposes, only those who have been trained
or demonstrate relevant skills can install and maintain this microinverter under the guidance of this
document.
1.3 Symbols Used
The safety symbols in this user manual are shown as below.
Symbol Description
This indicates a hazardous situation that can result in deadly electric shocks,
other serious physical injuries, or re incidents.
This indicates that directions must be strictly followed to avoid safety hazards
including equipment damage and personal injury.
This indicates that the act is forbidden. You should stop, use caution and fully
understand the operations explained before proceeding.
1.4 Radio Interference Statement
This microinverter has been tested and complies with the requirements of CE EMC, meaning that it will not
be aected by electromagnetic interference. Please note that incorrect installation may cause electromag-
netic disturbances.
You can turn the equipment o and on to see if radio or television reception is interfered by this equipment.
If this equipment does cause harmful interference to radio or television, please try the following measures
to x the interference:
1) Relocate other apparatus’ antenna.
2) Move the microinverter farther away from the antenna.
3) Separate the microinverter and the antenna with metal/concrete materials or roof.
4) Contact your dealer or an experienced radio/TV technician for help.
Important Notes

© 2023 Hoymiles Power Electronics Inc. All rights reserved. 5
Three-phase Microinverter HMT-1600/1800/2000-4T
2. About Safety
2.1 Important Safety Instructions
The HMT-1600-4T/HMT-1800-4T/HMT-2000-4T microinverter is designed and tested according to interna-
tional safety requirements. However, certain safety precautions must be taken when installing and operat-
ing this inverter. The installer must read and follow all instructions, cautions and warnings in this installa-
tion manual.
• All operations including transportation, installation, start-up and maintenance must be carried out
by qualied, trained personnel.
• Check the product before installation to make sure there is no damage caused during transporta-
tion because such damage can compromise the insulation integrity and safety clearances. Choose
installation location carefully and adhere to specied cooling requirements. Unauthorized removal
of necessary protections, improper use, incorrect installation and operation may cause damage to
the equipment or incur serious safety and shock hazards.
• You should get necessary approvals from local power operator before connecting the microinvert-
er to the power grid. This connection must be made only by qualied technical personnel. It is the
responsibility of the installer to provide external disconnect switches and Over Current Protection
Devices (OCPD).
• Each input of the inverter is connected to one PV module. Do not connect batteries or other
sources of power supply. The inverter can be used only if all the technical parameters are observed
and applied.
• Do not install the equipment in ammable, explosive, corrosive, extremely hot/cold, and humid en-
vironment. Do not use the equipment when safety devices in these environments are not working.
• Personal protective equipment such as gloves and goggles must be used during installation.
• Inform the manufacturer about non-standard installation conditions.
• Do not use the equipment if any operating anomalies are found.
• All repairs must be done with qualied spare parts which must be installed in accordance with their
intended use and by a licensed contractor or authorized Hoymiles service representative.
• Liabilities arising from components that are not produced by Hoymiles are on the part of their re-
spective manufacturers.
• Whenever the inverter has been disconnected from the public grid, please be extremely careful as
some components can retain charge sucient to create a shock hazard. Before touching any part
of the inverter, please ensure the surface and the whole equipment are within the limit of safe tem-
perature and voltage potential.
• Hoymiles is not liable for any damage caused by incorrect or improper operation.
• Electrical installation and maintenance shall be conducted by licensed electrician and shall comply
with local wiring rules.
About Safety

© 2023 Hoymiles Power Electronics Inc. All rights reserved. 6
Three-phase Microinverter HMT-1600/1800/2000-4T
2.2 Explanation of Symbols
Symbol Usage
Treatment
To comply with European Directive 2002/96/EC on Waste Electrical and Electron-
ic Equipment and its implementation as national law, electrical equipment that
has reached the end of its life must be collected separately and returned to an
approved recycling facility. Any device no longer needed must be returned to an
authorized dealer or approved collection and recycling facility.
Caution
Risk of electric shock due to stored energy. Don’t have any operation before
resifual voltage released.
Do not come within 8 inches (20 cm) of the microinverter when it is in operation.
Danger of high voltage
High voltage in the microinverter can cause dangers to life.
Beware of hot surface
The inverter can become hot during operation. Avoid contact with metal surfac-
es during operation.
CE mark
The inverter complies with the Low Voltage Directive for the European Union.
Read manual rst
Please read the installation manual rst before installation, operation and main-
tenance.
About Safety

© 2023 Hoymiles Power Electronics Inc. All rights reserved. 7
Three-phase Microinverter HMT-1600/1800/2000-4T
3. About Product
3.1 About PV Inverter System
A typical grid-tied PV inverter system includes PV modules, PV inverter, meter and power grid, as shown
below. PV inverter converts the DC power generated by PV modules into AC power that meets the require-
ments of the power grid. The AC power is then fed into the grid via meter.
About Product
A PV module
B PV inverter
C Grid-connected metering device
D Power grid
3.2 About Microinverter
The PV microinverter is a solar inverter that operates at the module level, using Maximum Power Point Track-
ing (MPPT) to track the maximum DC power point of each PV module.
The Hoymiles HMT-2000-4T series microinverters are equipped with module-level monitoring, which collects
microinverter data wirelessly and sends it to the Hoymiles monitoring platform, S-Miles Cloud.
The HMT-2000-4T microinverter’s MPPT circuit is less susceptible to partial shading. With dual MPPT, the
other MPPT can operate the unshaded string at maximum eciency point when one MPPT fails or is shaded,
ensuring the inverter delivers optimum performance under dierent partial shading situations.
Furthermore, the HMT-2000-4T microinverter carries only a few dozen volts of DC voltage, which signicantly
reduces safety hazards.

© 2023 Hoymiles Power Electronics Inc. All rights reserved. 8
Three-phase Microinverter HMT-1600/1800/2000-4T
This manual is about Hoymiles 4-in-1 microinverter. With the output power up to 2000 VA, Hoymiles new
HMT-2000 series rank among the highest for 4-in-1 microinverters.
Each microinverter connects to four PV modules at most with module-level MPPT and monitoring, enabling
greater energy harvest and easier maintenance.
3.4 About Sub-1G Technology
HMT-2000 series of microinverter adopts the new Sub-1G wireless solution which enables more stable com-
munication with Hoymiles gateway DTU. Sub-1G technology is particularly useful for PV microinverters and
is dierent from 2.4GHz in that it has substantially longer range and better interference suppression perfor-
mance.
Range of Sub-1GHz wireless: Unlike Wi-Fi or Zigbee which both operate on the 2.4 GHz band, Sub-1GHz op-
erates on the 868 MHz or the 915 MHz band. Generally speaking, Sub-1GHz wireless transmission covers 1.5
to 2 times longer distance than the 2.4GHz spectrum.
Interference: Sub-1GHz wireless networking can handle interference better. This is because it operates on a
lower frequency, so the communication between the microinverter and the DTU is more stable. As a result, it
is especially useful in industrial or commercial PV power plants.
Lower Power Consumption: Sub-1GHz wireless communication uses less power than Wi-Fi or Zigbee.
Because of the long range and better interference suppression performance, Sub-1GHz networking is partic-
ularly well-suited for rooftop PV power stations.
About Product
3.3 About 4-in-1 Unit
Microinverters can be divided into 1-in-1, 2-in-1, 4-in-1, etc., depending on how many PV modules are con-
nected to them. This means that the microinverter can connect to one module, two modules and four mod-
ules respectively, as shown below.
Sub-1G
Microinverter
Sub-1G Sub-1G
3.5 Highlights
- Three-phase output, more suitable for commercial and industrial applications
- With output power up to 2000 VA, compatible with 182 mm/210 mm PV module
- Grid protection relay integrated
- 4-in-1 design enables faster installation and lower cost
- Safer for rooftop solar stations with rapid shutdown compliance and isolated transformer
- Sub-1G wireless solution allows stable communication in commercial and industrial settings

© 2023 Hoymiles Power Electronics Inc. All rights reserved. 9
Three-phase Microinverter HMT-1600/1800/2000-4T About Product / Installation Preparation
3.7 Dimensions (mm)
3.6 Terminals Introduction
Object Description
A DC Connectors
B Sub-1G Wireless Terminal
C AC Sub Connector
216.8
102
326
222
272
CBA
++
+
+
-
--
-

© 2023 Hoymiles Power Electronics Inc. All rights reserved. 10
Three-phase Microinverter HMT-1600/1800/2000-4T
Note: The voltage of modules (considering the eect of local temperature) must not exceed the maximum input
voltage of the microinverter. Otherwise, the microinverter may be damaged (refer to the Technical Data section to
determine the absolute maximum input voltage).
Installation Preparation
A PV module
B DC extension cable
C Microinverter
4. Installation Preparation
4.1 Position and Space Required
Please install the microinverter and all DC connections under the PV module to avoid direct sunlight, rain
exposure, snow buildup, UV etc. The silver side of the microinverter should be up and facing the PV module.
Leave a minimum of 2 cm of space around the microinverter enclosure to ensure ventilation and heat dissi-
pation.
Note: In some countries, DTU will be required to meet local grid regulations (e.g. G98/99 for UK etc.)
4.2 Connecting Multiple PV Modules to Microinverter
General Guidelines:
1. PV modules should be connected to DC input ports of a microinverter.
2. Use DC extension cable when the original cable is not long enough. Please consult the local power opera-
tor to make sure that the DC cable complies with local regulations.
Two typical wiring methods are shown below.
A B C

© 2023 Hoymiles Power Electronics Inc. All rights reserved. 11
Three-phase Microinverter HMT-1600/1800/2000-4T
4.3 Installation Tools
Besides tools recommended below, other auxiliary tools can also be used on site.
Screwdriver Multimeter
Socket Wrench or Allen wrench Marker pen
Diagonal pliers Steel tap
Wire cutters Cable tie
Wire stripper Torque and adjustable wrench
Utility knife
Safety glove Dust masks
Protective goggles Safety shoes
HMT-1600-4T HMT-1800-4T HMT-2000-4T Maximum over current
protection device (OCPD)
Maximum number
per 12 AWG branch
8@220 V
8@230 V
9@240 V
7@220 V
7@230 V
8@240 V
6@220 V
6@230 V
7@240 V
20 A
Maximum number
per 10 AWG branch
13@220 V
13@230 V
14@240 V
11@220 V
12@230 V
12@240 V
11@220 V
11@230 V
11@240 V
32 A
4.4 AC Branch Circuit Capacity
Hoymiles HMT-1600-4T/HMT-1800-4T/HMT-2000-4T can be used with 12AWG or 10AWG AC Trunk Cable and
the AC Trunk Connector which are provided by Hoymiles. The number of microinverters on each 12AWG or
10AWG AC branch shall not exceed the limit as shown below.
Note:
• The number of microinverters that can be connected to each AC branch is determined by the ampacity (also
known as current-carrying capacity) of the cable.
• 1-in-1, 2-in-1 and 4-in-1 microinverters can be connected to the same AC branch, as long as the total current
does not exceed the ampacity specied in local regulations.

© 2023 Hoymiles Power Electronics Inc. All rights reserved. 12
Three-phase Microinverter HMT-1600/1800/2000-4T Installation Preparation
Installation location shall meet the following conditions:
• The installation must be done with the equipment disconnected from the grid (power disconnect
switch open) and with the PV modules shaded or isolated.
• Make sure the environmental conditions t the microinverter’s requirement (degree of protection,
temperature, humidity, altitude, etc.) as specied in the Technical Data section.
• Avoid direct sunlight to prevent power derating which can be caused by an increase in the internal
temperature of the microinverter.
• Keep the inverter in well-ventilated place to avoid overheating.
• Keep the inverter away from gases or ammable substances.
• Avoid electromagnetic interference because it can compromise the normal operation of electronic
equipment.
• Install only on structures specically designed for PV modules (supplied by installation technicians).
• Install microinverter underneath PV modules to make sure it works in the shadow. Nonobservance
may cause the derating of inverter production.
4.5 Precautions
The equipment is installed based on the system design and the location of installation.

© 2023 Hoymiles Power Electronics Inc. All rights reserved. 13
Three-phase Microinverter HMT-1600/1800/2000-4T
5. Microinverter Installation
5.1 Accessories
Item Description
A 3P-AC Trunk Cable, 12/10 AWG Cable
B M8 × 25 screws (Prepared by the installer)
CGrounding Accessory
D3P-AC Trunk Connector
E 3P-AC Trunk Port Cap
F 3P-AC Trunk Port Disconnect Tool
G 3P-AC Trunk End Cap
H 3P-AC Trunk Connector Unlock Tool
Note: All accessories above are not included in the package and should be purchased separately.
About Installation
5.2 Installation Steps
The order of Step 1 and Step 2 can be reversed according to your planned needs.
Step 1. Plan and Install the Microinverter
A ) Mark the position of each microinverter on the rail according to the PV module layout.
B ) Fix the screws on the rail.
C ) Hang the microinverter (label side
up) on the screws and beneath the
PV module. Then tighten the screws.
Mounting Torque : 9 N·m
F
CD H
ABEG

© 2023 Hoymiles Power Electronics Inc. All rights reserved. 14
Three-phase Microinverter HMT-1600/1800/2000-4T
The AC cable contains earth wire, so grounding can be done directly with it. For regions that have special
requirements, we oer optional grounding brackets that can be used to complete the external ground-
ing.
Route a continuous grounding cable through grounding brackets for each microinverter to the AC
grounding electrode that conforms with local regulations.
Torque each grounding cleat screw to 2 N·m.
Note:
• Microinverter installation and DC connections must be done under the PV module to avoid direct sunlight,
rain exposure, snow buildup, UV etc.
• Leave a minimum of 2 cm of space around the microinverter enclosure to ensure ventilation and heat dissi-
pation.
• Mounting torque of the 8 mm screw is 9 N·m. Do not over torque.
• Do not pull or hold the AC cable with your hand. Hold the handle instead.
Step 2. Plan and Build the 3P-AC Trunk Cable
3P-AC Trunk Cable is used to connect the microinverter to distribution box.
A ) Determine how many microinverters you plan to install on each AC branch and prepare AC Trunk
Connectors accordingly.
B ) Take out segments of AC Trunk Cable as you need to make AC branch.
- Use the 3P-AC Trunk Connector
Unlock Tool to unlock the
connector upper cover.
1 ) Disassemble the AC Trunk Connector and remove the cable.
About Installation

© 2023 Hoymiles Power Electronics Inc. All rights reserved. 15
Three-phase Microinverter HMT-1600/1800/2000-4T
- Loosen the three screws with the
screwdriver. Untighten the cap
and remove the cable.
- Insert the 3P-AC Trunk End Cap
and screw the cap back to port,
then tighten the cap.
- Unlock the port upper cover,
loosen the screws with screwdriver
and remove the extra cable. (Skip
this step if there is no cable at this
side.)
- Prepare a segment of AC cable of
suitable length to connect to the
distribution box, with stripping
requirements fullled.
- Insert the cable into the cap in a
way that theL1, L2, L3, PE and N
lines are in corresponding slots.
- Tighten the screws, and then
tighten the cap back to the port.
- Plug the upper cover back to the
Trunk connector.
About Installation
2 ) Install the 3P-AC Trunk End Cap at one side of 3P-AC Trunk Cable (The end of 3P-AC Trunk Cable).
3 ) Install AC end cable on the other side of 3P-AC Trunk Cable (connected to the distribution box).
- Plug the upper cover back to the
Trunk connector.
Note:
• Tightening torque of the cap: 5.5±0.5 N·m. Please do not over-torque.
• Torque of locking screw: 0.4±0.1 N·m.
• Do not damage the sealing ring in the 3P-AC Trunk Connector during disassembly and assembly.
• Wires used in Hoymiles Microinverter:
C ) Repeat the above steps to make all the 3P-AC Trunk Cables you need, then lay out the cable on the
rail in the suitable position so that the microinverters can be connected to the Trunk connectors.
D ) Attach the 3P-AC Trunk Cable to
the mounting rail and x the cable
with tie wraps.
5.5±0.5N·m
click
8±1mm
70±5mm
N
PE
L3
L2
L1
5.5±0.5N·m
0.4±0.1N·m
click
PE (Green&Yellow) N (Blue) L1 (Brown) L2 (Black) L3 (Gray)

© 2023 Hoymiles Power Electronics Inc. All rights reserved. 16
Three-phase Microinverter HMT-1600/1800/2000-4T About Installation
Note:
• Make sure that the 3P-AC Trunk Connectors are kept away from any drainage channels.
• In case you need to remove the microinverter AC cable from 3P-AC Trunk Connector, insert
the 3P-AC Trunk Port Disconnect Tool into the side of AC Sub Connector to complete the
removal.
A ) Plug the AC Sub Connector of the
microinverter into the 3P-AC Trunk
Connector until you hear the click.
A) Peel the removable serial number
label from each microinverter.
B) Ax the serial number label to the
respective location on the installa-
tion map (please refer to the ap-
pendix).
A) Mount the PV modules above the
microinverter.
B) Connect the PV modules’ DC cables
to the DC input side of the microin-
verter.
C ) Please plug the 3P-AC Trunk Port
Cap in any vacant AC Trunk Port to
make it water and dust-proof.
Step 3. Complete the AC Connection
B ) Connect the AC end cable to the distribution box, and wire it to the local grid network.
Product information is subject to change without notice. (Please download reference manuals at www.hoymiles.com)
Step 4. Create an Installation Map
Step 5. Connect PV Modules
Step 6. Energize the System
A) Turn on the AC breaker of the branch circuit.
B) Turn on the main AC breaker of the house. Your system will start to generate power in about two
minutes.
Note:
• Make sure that the 3P-AC Trunk Connectors are kept away from any drainage channels.
• In case you need to remove the microinverter AC cable from 3P-AC Trunk Connector, insert the AC Trunk Port Disconnect Tool
into the side of AC Sub Connector to complete the removal.
Step 7. Set Up Monitoring System
Refer to the “DTU User Manual”, “DTU Quick Installation Guide”, and “Quick Installation Guide for S-Miles
Cloud” to install the DTU and set up the monitoring system.
Click
click
Tosheet ______
Tosheet ______
Tosheet ______
Tosheet ______
Sheet_____of_____
Hoymiles Microinvert er Installation Map
PleaseMake N for North
1
A
B
C
D
23456789 10 11 12 13 14 15 16
COLUMN
ROW
AP040228 V1.3
CustomerInformation: DTU Serial Number
Azimuth:
Tilt:
Panel type:
136164700571
136164700571

© 2023 Hoymiles Power Electronics Inc. All rights reserved. 17
Three-phase Microinverter HMT-1600/1800/2000-4T
6. Troubleshooting
6.1 Troubleshooting List
Code Alarm range Alarm status Handling suggestions
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 support.
125 Grid conguration
parameter error
1.Check if the grid conguration parameter is correct and upgrade
again.
2. If the fault still exists, contact your dealer or Hoymiles technical
support.
126 Software error code 126
1. If the alarm occurs accidentally and the microinverter can still work
normally, no special treatment is required.
2. If the alarm occurs frequently and cannot be recovered, contact your
dealer or Hoymiles technical support.
127 Firmware error
1.Check if the rmware is correct and upgrade again.
2.Check the communication between DTU and Hoymiles monitoring
system, the communication between DTU and microinverter. Then try
again.
3. If the fault still exists, contact your dealer or Hoymiles technical
support.
128 Software error code 128
1. If the alarm occurs accidentally and the microinverter can still
work normally, no special treatment is required.
2. If the alarm occurs frequently and cannot be recovered,
contact your dealer or Hoymiles technical support.
129 Software error code 129
1. If the alarm occurs accidentally and the microinverter can still work
normally, no special treatment is required.
2. If the alarm occurs frequently and cannot be recovered, contact your
dealer or Hoymiles technical support.
130 Oine
1.Please make sure that the microinverter works normally.
2.Check the communication status between the DTU and hoymiles
monitoring system or between the DTU and the microinverter.If the
communication is poor, try to make some improvements.
3. If the alarm occurs frequently and cannot be recovered, contact your
dealer or Hoymiles technical support.
141 Grid Grid overvoltage
1. If the alarm occurs accidentally, the grid voltage may be abnormal
temporarily. The microinverter can recover automatically after grid
voltage becomes normal.
2. If the alarm occurs frequently, check whether the grid voltage is
within the acceptable range. If no, contact the local power operator or
change the grid overvoltage protection limit via Hoymiles monitoring
system with the consent of the local power operator.
142 Grid 10 min value grid
overvoltage
1. If the alarm occurs accidentally, the grid voltage may be abnormal
temporarily. The microinverter can recover automatically after grid
voltage becomes normal.
2. If the alarm occurs frequently, check whether the grid voltage is
within the acceptable range. If no, contact the local power operator
or change the grid overvoltage protection limit via Hoymiles
monitoring system with the consent of the local power operator.
143 Grid Grid undervoltage
1. If the alarm occurs accidentally, the grid voltage may be abnormal
temporarily. The microinverter can recover automatically after grid
voltage becomes normal.
2. If the alarm occurs frequently, check whether the grid voltage is
within the acceptable range. If no, contact the local power operator
or change the grid overvoltage protection limit via Hoymiles
monitoring system with the consent of the local power operator.
Troubleshooting

© 2023 Hoymiles Power Electronics Inc. All rights reserved. 18
Three-phase Microinverter HMT-1600/1800/2000-4T Troubleshooting
144 Grid Grid overfrequency
1. If the alarm occurs accidentally, the grid frequency may be
abnormal temporarily. The microinverter can recover automatically
after grid frequency becomes normal.
2. If the alarm occurs frequently, check whether the grid frequency is
within the acceptable range. If no, 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 accidentally, the grid frequency may be
abnormal temporarily. The microinverter can recover automatically
after grid frequency becomes normal.
2. If the alarm occurs frequently, check whether the grid frequency is
within the acceptable range. If no, 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 accidentally, the grid frequency may be
abnormal temporarily. The microinverter can recover automatically
after grid frequency becomes normal.
2. If the alarm occurs frequently, check whether the grid frequency
change rate is within the acceptable range. If no, contact the local
power operator or change the grid frequency change rate limit via
Hoymiles monitoring system with the consent of the local power
operator.
147 Grid Power grid outage Please check whether there is a power grid outage.
148 Grid Grid disconnection Please check whether the AC switch or AC wiring is normal.
149 Grid Island detected
1. If the alarm occurs accidentally, the grid voltage may be abnormal
temporarily. The microinverter can recover automatically 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, contact your dealer or Hoymiles technical
support.
171
Abnormal phase
dierence between phase
to phase
Please check that the wiring of each phase is completely correct. This
fault is usually caused by the wrong phase.
205 Input port 1&2
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.
206 Input port 3&4
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.
207 Input port 1&2
undervoltage
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.
208 Input port 3&4
undervoltage
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.
209 Port 1 No input
1. Please conrm 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.
210 Port 2 No input
1. Please conrm 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.

© 2023 Hoymiles Power Electronics Inc. All rights reserved. 19
Three-phase Microinverter HMT-1600/1800/2000-4T Troubleshooting
211 Port 3 No input
1. Please conrm 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.
212 Port 4 No input
1. Please conrm 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.
213 PV-1 & PV-2
abnormal wiring
Please check whether the DC connections on port 1 and 2 are
correct.
214 PV-3 & PV-4
abnormal wiring
Please check whether the DC connections on port 3 and 4 are
correct.
221 Abnormal wiring of grid
neutral line
Please conrm whether the grid neutral lines of the microinverters
are connected to the neutral of the grid correctly.
301 Hardware Error Code 301
1. If the alarm occurs accidentally and the microinverter can still
work normally, no special treatment is required.
2. If the alarm occurs frequently and cannot be recovered, contact
your dealer or Hoymiles technical support.
302 Hardware Error Code 302
1. If the alarm occurs accidentally and the microinverter can still
work normally, no special treatment is required.
2. If the alarm occurs frequently and cannot be recovered, contact
your dealer or Hoymiles technical support.
303 Hardware Error Code 303
1. If the alarm occurs accidentally and the microinverter can still
work normally, no special treatment is required.
2. If the alarm occurs frequently and cannot be recovered, contact
your dealer or Hoymiles technical support.
304 Hardware Error Code 304
1. If the alarm occurs accidentally and the microinverter can still
work normally, no special treatment is required.
2. If the alarm occurs frequently and cannot be recovered, contact
your dealer or Hoymiles technical support.
305 Hardware Error Code 305
1. If the alarm occurs accidentally and the microinverter can still
work normally, no special treatment is required.
2. If the alarm occurs frequently and cannot be recovered, contact
your dealer or Hoymiles technical support.
306 Hardware Error Code 306
1. If the alarm occurs accidentally and the microinverter can still
work normally, no special treatment is required.
2. If the alarm occurs frequently and cannot be recovered, contact
your dealer or Hoymiles technical support.
307 Hardware Error Code 307
1. If the alarm occurs accidentally and the microinverter can still
work normally, no special treatment is required.
2. If the alarm occurs frequently and cannot be recovered, contact
your dealer or Hoymiles technical support.
308 Hardware Error Code 308
1. If the alarm occurs accidentally and the microinverter can still
work normally, no special treatment is required.
2. If the alarm occurs frequently and cannot be recovered, contact
your dealer or Hoymiles technical support.
309 Hardware Error Code 309
1. If the alarm occurs accidentally and the microinverter can still
work normally, no special treatment is required.
2. If the alarm occurs frequently and cannot be recovered, contact
your dealer or Hoymiles technical support.
310 Hardware Error Code 310
1. If the alarm occurs accidentally and the microinverter can still
work normally, no special treatment is required.
2. If the alarm occurs frequently and cannot be recovered, contact
your dealer or Hoymiles technical support.
311 Hardware Error Code 311
1. If the alarm occurs accidentally and the microinverter can still
work normally, no special treatment is required.
2. If the alarm occurs frequently and cannot be recovered, contact
your dealer or Hoymiles technical support.

© 2023 Hoymiles Power Electronics Inc. All rights reserved. 20
Three-phase Microinverter HMT-1600/1800/2000-4T Troubleshooting
6.2 LED Indicator Status
The LED ashes ve times at start-up. All green ashes (1s gap) indicate normal start-up.
(1) During Start-up
• Flashing green ve times (0.3s gap): Start-up success
• Flashing Red ve times (0.3s gap): Start-up failure
• Fast red ashes (0.2s gap): The Neutral wire is not properly connected
(2) During Operation
• Fast green ashes (1s gap): Producing power
• Slow green ashes (2s gap): Producing power but one input is abnormal
• Red ashes (0.5s gap): Invalid AC grid or hardware failure. Refer to Hoymiles Monitoring Platform for
more details
• Red ashes (1s gap): Not producing power due to invalid AC grid
• Solid red: Hardware failure. Please refer to Hoymiles Monitoring Platform for more details
(3) Other Status
• Red and Green ashes alternately: Firmware is broken
Note:
• The microinverter is powered by DC side. If the LED light is not on, please check the DC side connection. If the
connection and input voltage are normal, contact your dealer or hoymiles technical support team.
• All the faults are reported to the DTU. Refer to the local DTU app or Hoymiles Monitoring Platform for more
information.
LED