Hoymiles eLumen HMT-1800 User manual

© 2021 Hoymiles Power Electronics Inc. All rights reserved. 01
Three-phase Microinverter HMT-1800/2250
User Manual
Three-phase Microinverter HMT-1800/2250
Version 1.1 ( 2021)EN

© 2021 Hoymiles Power Electronics Inc. All rights reserved. 01
Three-phase Microinverter HMT-1800/2250
About Microinverter
This system is composed of a group of three-phase microinverters that convert direct current (DC) into
alternating current (AC) and feed it into the public grid. The system is designed for the incorporation of
one microinverter for six PV modules.
Each microinverter works independently and guarantees the maximum power generation of each
PV module. This setup enables the user to directly control the production of a single PV module,
consequently improving the flexibility and reliability of the system.
About the Manual
This manual contains important instructions for the HMT-1800/HMT-2250 Microinverter and must be
read in its entirety before installing or commissioning the equipment.
For safety purposes, only a qualified technician who has received training or has demonstrated
competence may install and maintain this microinverter under the guidance of this document.
Other Information
Product information is subject to change without notice. The user manual will be frequently updated,
refer to Hoymiles official website at www.hoymiles.com for the latest version.

© 2021 Hoymiles Power Electronics Inc. All rights reserved. 02
Three-phase Microinverter HMT-1800/2250
CONTENTS
1. Important Notes 03
1.1 Product Range 03
1.2 Microinverter Accessories 03
1.3 Target Group 03
1.4 Symbols Used 03
1.5 Radio Interference Statement 03
2. About Safety 04
2.1 Important Safety Instructions 04
2.2 Explanation of Symbols 05
3. About Product 06
3.1 About Three-Phase Microinverter 06
3.2 About Sub-1G technology 06
3.3 Highlights 06
3.4 Terminals Introduction 07
3.5 Dimension(mm) 07
4. Installation Preparation 08
4.1 Module Compatibity 08
4.2 AC Branch Circuit Capacity 08
4.3 Position and Space Required 08
4.4 Grounding Consideration 08
5. Microinverter Installation 09
5.1 Accessories 09
5.2 Pre-installation 09
5.3 Installation Steps 10
6. Troubleshooting 12
6.1 Troubleshooting List 12
6.2 Status LED Indicator 16
6.3 On-site Inspection (For qualified installer only) 17
6.4 Routine Maintenance 17
6.5 Replace Microinverter 18
7. Decommissions 19
7.1 Decommissions 19
7.2 Storage and Transportation 19
7.3 Disposal 19
8. Technical Data 20
8.1 DC Input 20
8.2 AC Output 20
8.3 Efficiency, Safety and Protection 21
8.4 Mechanical Data 21
8.5 Features 21
Appendix 1: 22
Installation Map 22
Appendix 2: 23
WIRING DIAGRAM – 230VAC / 400VAC THREE PHASE: 23

© 2021 Hoymiles Power Electronics Inc. All rights reserved. 03
Three-phase Microinverter HMT-1800/2250 Important Notes
1. Important Notes
1.1 Product Range
This manual describes the assembly, installation, commissioning, maintenance and failure search for the
following models of the Hoymiles three-phase microinverter:
• HMT-1800-6T
• HMT-2250-6T
*Note: “1800” means 1800W, “2250” means 2250W.
1.2 Microinverter Accessories
The Hoymiles HMT series three-phase microinverter needs to be used with special three-phase system ac-
cessories, including the three-phase bus cable, unlocking tool, end cap, and so on. See Chapter 5.1 for more
information.
A DTU is required if the user wants to see the information and solar production on the Hoymiles Monitoring
System.
1.3 Target Group
For safety purposes, only a qualied technician who has received training or has demonstrated competence
may install and maintain this microinverter under the guidance of this document.
1.4 Symbols Used
The safety symbols in this user manual are shown below.
Symbol Usage
Indicates a hazardous situation that can result in deadly electric shock hazards,
other serious physical injury, or fire hazards.
Indicates directions which must be fully understood and followed in their
entirety to avoid potential safety hazards, including equipment damage or
personal injury.
Indicates that the described operation must not be carried out. The reader
should stop, use with caution and fully understand the operations explained
before proceeding.
1.5 Radio Interference Statement
This microinverter has been tested and found to comply with the limits for CE EMC, which provides reason-
able protection against harmful energy. However, if not installed according to the instructions, the microin-
verter may cause harmful interference to radio equipment. There is no guarantee that such interference will
not occur during a particular installation.
To conrm that the radio or television reception is affected by interference from this equipment, turn the
equipment off and on to test it. If this equipment causes harmful interference to the radio or television
equipment, try to correct the interference through one or more of the following measures:
1) Relocate the receiving antenna.
2) Increase the separation between the microinverter and the receiving antenna.
3) Place a shield between the microinverter and the receiving antenna, such as a metal / concrete roof.
4) Contact your dealer or an experienced radio/TV technician for help.

© 2021 Hoymiles Power Electronics Inc. All rights reserved. 04
Three-phase Microinverter HMT-1800/2250 About Safety
2. About Safety
2.1 Important Safety Instructions
The HMT-1800/HMT-2250 Three-phase Microinverter is designed and tested according to international safety
requirements. However, certain safety precautions must be taken when installing and operating this mi-
croinverter. The installer must read and follow all instructions, precautions and warnings in this installation
manual.
• All operations including transport, installation, start-up and maintenance must be carried out by
qualied and trained personnel.
• Before installation, check the unit to ensure that it is free of any transport or handling damage,
which could affect insulation integrity or safety clearances. Choose an installation location carefully
and adhere to the specied cooling requirements. Unauthorized removal of necessary protections,
improper use, and incorrect installation and operation may result in serious safety and shock hazards
or equipment damage.
• Before connecting the microinverter to the power distribution grid, contact the local power distri-
bution grid company to obtain the appropriate approvals. This connection must be made only by
qualied technical personnel. It is the responsibility of the installer to provide external disconnect
switches and Overcurrent Protection Devices (OCPD).
• Usually only one PV module can be connected to one input of the microinverter. Do not connect
batteries or other power supply sources. The microinverter can be used only if all the technical char-
acteristics are observed and applied.
• Do not install the equipment in adverse environments, such as environments that are ammable,
explosive, corrosive, extremely hot or cold, or humid. Do not use the equipment when the safety
devices do not work or are disabled.
• Always use personal protective equipment, including gloves and eye protection, while installing.
• Inform the manufacturer of non-standard installation conditions.
• Do not use the equipment if any anomalies are discovered while operating. Avoid temporary repairs.
• All repairs should be carried out by using only qualied spare parts, which must be installed in accor-
dance with their intended use and by a licensed contractor or authorized Hoymiles service represen-
tative.
• Any liability arising from commercial components are delegated to their respective manufacturers.
• Any time the microinverter has been disconnected from the public network, please be extremely
cautious, as some components can retain charge sucient to create a shock hazard. Prior to
touching any part of the microinverter, please ensure that surfaces and equipment are under safe
touch temperatures and voltage potentials before proceeding.
• Hoymiles accepts no liability for damage due to incorrect or improper operation.
• Electrical Installation & Maintenance shall be conducted by a licensed electrician and shall comply
with local wiring regulations.

© 2021 Hoymiles Power Electronics Inc. All rights reserved. 05
Three-phase Microinverter HMT-1800/2250 About Safety
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 separately collected and returned to an
approved recycling facility. Any device no longer required must be returned to an
authorized dealer or approved collection and recycling facility.
Caution
Do not come within 8 inches of the microinverter for any length of time while it is
in operation.
Danger of high voltages
Danger to life due to high voltage in the microinverter.
Beware of hot surface
The microinverter can become hot while operating. Avoid contact with metal sur-
faces while operating.
CE mark
The microinverter complies with the requirements of the Low Voltage Directive
for the European Union.
Read manual rst
Please read the installation manual rst before installation, operation and main-
tenance.

© 2021 Hoymiles Power Electronics Inc. All rights reserved. 06
Three-phase Microinverter HMT-1800/2250 About Product
3. About Product
3.1 About Three-phase Microinverter
The world's rst three-phase microinverter with Reactive Power Control that can be widely used in the general
230V/400V three-phase electric power distribution. Each microinverter, with up to 6 PV modules connected,
simplies the installation process and ranks among the most cost-effective solutions for commercial and
industrial installations.
3.2 About Sub-1G Technology
Sub-1G technology is particularly useful for PV microinverters, and different from technologies such as
2.4GHz in , it has substantially better range and interference suppression performance.
Range of Sub-1GHz
Wireless:
Unlike Wi-Fi and Zigbee, which both operate on the 2.4 GHz band, Sub-1GHz
operates on the 868 MHz or the 915 MHz bands. Usually, Sub-1GHz wireless
transmission offers 1.5-2 times more distance coverage than the 2.4 GHz
spectrum.
Interference: Sub-1GHz wireless can handle interference better. This is because it
operates on a lower frequency which can communicate better between PV
modules and rooftops, and is especially useful in an industrial or commer-
cial PV plant. This means that the communication between the microinvert-
ers and the DTU will be more stable.
Lower Power Consump-
tion:
Sub-1GHz wireless typically uses less power than Wi-Fi or Zigbee.
Because of the long range and better interference suppression performance, Sub-1GHz networking is par-
ticularly well-suited to rooftop PV plants.
3.3 Highlights
• Three-phase output, more suitable for commercial and industrial applications.
• Each microinverter supports up to 6 modules, faster installation and lower cost.
• Up to 2250VA output, adapted to mainstream high-powered PV modules.
• With Reactive Power Control, in accordance with EN 50549-1:2019, VDE-AR-N 4105:2018, TOR Erzeu-
ger: 2019-12, and so on.
• The Sub-1G wireless solution enables stable communication when installed for commercial and
industrial plants.

© 2021 Hoymiles Power Electronics Inc. All rights reserved. 07
Three-phase Microinverter HMT-1800/2250 About Product
3.4 Terminals Introduction
CAB
Object Description
A Sub-1G Wireless Terminal
B DC Connectors
C AC Connector
3.5 Dimensions (mm)
326
245
288
146.5
140
500

© 2021 Hoymiles Power Electronics Inc. All rights reserved. 08
Three-phase Microinverter HMT-1800/2250 Installation Preparation
4. Installation Preparation
4.1 Module Compatibility
The Hoymiles HMT series HMT-1800/HMT-2250 are compatible with most 60-cell and 72-cell PV modules.
For other types of PV modules, ensure that they are electrically paired with Hoymiles microinverters. See the
Technical Data page of this user manual for more information.
4.2 AC Branch Circuit Capacity
The Hoymiles HMT-1800/HMT-2250 can be used with the 12AWG or 10AWG AC bus cable and the AC bus con-
nectors, which are provided by Hoymiles. When preparing, do not exceed the limits on the maximum number
of microinverters per 12AWG or 10AWG AC branch, as shown below.
HMT-1800 HMT-2250 Maximum overcurrent
protection device (OCPD)
Maximum number per
12AWG branch 7(@230VAC) 6(@230VAC) 20A
Maximum number per
10AWG branch 11(@230VAC) 9(@230VAC) 30A
4.3 Position and Space Required
Install the microinverter and all DC connections under the PV module to avoid direct sunlight, rain exposure,
snow pile-up, UV, and so on. Also, the silver side of the microinverter should be up and should face the PV
module.
Allow a minimum of 2cm of space around the microinverter enclosure to ensure ventilation and heat dissipa-
tion.
4.4 Grounding Consideration
This microinverter is a Class I equipment with a basic isolation transformer, and this microinverter must be
earthed. There is an earth wire inside the AC cable, so usually grounding can be done by directly using this
wire. If the utility has any special requirements, grounding can be done by axing the mounting bracket to
the racking.

© 2021 Hoymiles Power Electronics Inc. All rights reserved. 09
Three-phase Microinverter HMT-1800/2250 Microinverter Installation
5. Microinverter Installation
5.1 Accessories
A B C D E F H G
Item Description
A 3P-AC Bus End Cap, IP67
B 3P-AC Connector Unlocking Tool
C 3P-AC Bus Connector
D 3P-Bus Connector Unlocking Tool
E 3P-AC Sub Cap
F M8*25 screws
G DC Extension Cable,1m
H 3P-AC Bus Cable, 12/10 AWG Optional
*Note: All accessories listed above are not included by the package, and must be purchased separately.
Please contact our sales representative for price information (M8 screws need to be prepared by install-
er-self).
5.2 Pre-installation
A) Plan the cable length to allow the bus cable to align with each PV module.
B) Install the AC bus end cap:
• Use the 3P-Bus connector unlocking
tool to unlock the connector's upper
cover.

© 2021 Hoymiles Power Electronics Inc. All rights reserved. 10
Three-phase Microinverter HMT-1800/2250 Microinverter Installation
• Loosen the ve screws with a
screwdriver. Untighten the nut as
shown in the picture and remove the
extra cable.
• Slightly screw the nut back into the
body, plug in the 3P-AC bus end cap,
and then tighten the nut.
• Plug the upper cover back into the
3P-AC bus connector.
5.3 Installation Steps
Note: The following installation steps are based on the 2*3 installation of PV modules. Other installations may re-
quire the use of more accessories.
Step 1. Attach Microinverter on Rail
A) Mark the approximate center of each panel on the frame.
B) Fix the screw on the rail.
Note: Install the microinverter with the silver side up under the PV module. Allow a minimum of 2cm around the
microinverter enclosure to ensure ventilation and heat dissipation.
Step 2. Complete AC Connection
A) Attach the 3P-AC Bus Cable to the
mounting rail and ax the cable with
ties.
Note: Minimize the distance between
the microinverter and the 3P-AC bus
connector for slack.
B) Take the AC connector from the
microinverter and push it into the
3P-AC bus connector until you hear a
clicking sound.
C) If any bus port is vacant, plug the 3P-AC
sub cap into the port to protect it from
dust and water.
Note: Under circumstances that require the
removal of the microinverter AC cable from the
3P-AC bus connector, use the 3P-AC connector
unlocking tool, and insert the tool into the side
of AC port to remove.

© 2021 Hoymiles Power Electronics Inc. All rights reserved. 11
Three-phase Microinverter HMT-1800/2250 Microinverter Installation
Step 3. Install AC End Cable
A) Prepare a 3P-AC end cable of proper
length, then insert one side of the
cable into the seal nut. Match the L1,
L2, L3, N and Ground line into the
slots accordingly. Tighten the screws,
and then tighten the cap back to the
connector. Plug the upper cover back
into the 3P-AC bus connector.
B) Connect the other side of the AC end
cable to the distribution box, and wire
it to the local grid network.
N
PE
L3
L2
L1
Step 4. Create an Installation Map
A) Peel the removable serial number label
from each microinverter (as shown in
the picture).
B) Ax the serial number label to the
respective location on the installation
map
o sheet ______
o sheet ______ AP040228 REV1.1
Panel Group:
Azimuth:
ilt:
Sheet_ of __
Customer Information DT Serial Number:
10 12 13 14
o sheet ________
o sheet ________
138264700571
138264700571
Step 5. Connect PV Modules
A) Mount the PV modules above the
microinverter.
B) Connect the PV modules’ DC cables to
the DC input side of the microinverter.
Step 6. Energize the System
A) Turn on the AC breaker for the branch circuit.
B) Turn on the main AC breaker for the house. The system will start to generate power after several min-
utes.
Step 7. Monitoring System Setup
Refer to the DTU User Manual, DTU Quick Installation Guide and Quick Installation Guide for S-Miles Cloud
(Hoymiles Monitoring Platform) Online Registration to install the DTU and set up the monitoring system.

© 2021 Hoymiles Power Electronics Inc. All rights reserved. 12
Three-phase Microinverter HMT-1800/2250 Troubleshooting
6. Troubleshooting
This microinverter (SN:1382xxxxxxxx) only works with the new Hoymiles DTU (DTU-Pro-S, DTU-Lite-S) with the
following serial numbers.
Model Serial Number
DTU-Pro-S 10FCxxxxxxxx
10FDxxxxxxxx
DTU-Lite-S 10D7xxxxxxxx
10D8xxxxxxxx
6.1 Troubleshooting List
Alarm Code Alarm Name Suggestion
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 Service Center.
125 Grid configuration
parameter error
1. Check if the grid configuration parameter is correct and upgrade
again.
2. If the fault still exists, contact your dealer or Hoymiles Technical
Service Center.
126 Software error code 126
1. If the alarm occurs accidentally and the microinverter can still function
normally, no special treatment is required.
2. If the alarm occurs frequently and cannot be restored, contact your
dealer or Hoymiles Technical Service Center.
127 Firmware error
1. Check if the firmware is correct and upgrade again.
2. Check the communication between the DTU and Hoymiles Monitoring
System, as well as the communication between the DTU and the
microinverter. Then try again.
3. If the fault still exists, contact your dealer or Hoymiles Technical
Service Center.
128 Software error code 128
1. If the alarm occurs accidentally and the microinverter can still function
normally, no special treatment is required.
2. If the alarm occurs frequently and cannot be restored, contact your
dealer or Hoymiles Technical Service Center.
129 Software error code 129
1. If the alarm occurs accidentally and the microinverter can still function
normally, no special treatment is required.
2. If the alarm occurs frequently and cannot be restored, contact your
dealer or Hoymiles Technical Service Center.
130 Offline
1. Please check if the microinverter works normally.
2. Check the communication status between the DTU and Hoymiles
Monitoring System, or between the DTU and the microinverter. Try to
make improvements if the communication is poor.
3. If the alarm occurs frequently and cannot be restored, contact your
dealer or Hoymiles Technical Service Center.
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.

© 2021 Hoymiles Power Electronics Inc. All rights reserved. 13
Three-phase Microinverter HMT-1800/2250 Troubleshooting
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 overvoltage protection limit via the Hoymiles Monitoring
System after obtaining the consent of the local power operator.
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.
171
Abnormal phase
difference between
phases
Check that the wiring of each phase is 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 not within the normal range,
contact your dealer or Hoymiles Technical Service Center.

© 2021 Hoymiles Power Electronics Inc. All rights reserved. 14
Three-phase Microinverter HMT-1800/2250 Troubleshooting
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 not within the normal range,
contact your dealer or Hoymiles Technical Service Center.
215 Input Port 5 & 6
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 not within the normal range,
contact your dealer or Hoymiles Technical Service Center.
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 not within the normal range,
contact your dealer or Hoymiles Technical Service Center.
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 not within the normal range,
contact your dealer or Hoymiles Technical Service Center.
216 Input Port 5 & 6
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 not within the normal range,
contact your dealer or Hoymiles Technical Service Center.
209 Port 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.
210 Port 2 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.
211 Port 3 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.
212 Port 4 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.
217 Port 5 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.
218 Port 6 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.
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.
219 PV-5 & PV-6 abnormal
wiring Please check whether the DC connections on Port 5 and 6 are correct.

© 2021 Hoymiles Power Electronics Inc. All rights reserved. 15
Three-phase Microinverter HMT-1800/2250 Troubleshooting
221 Abnormal wiring of grid
neutral line
Confirm whether the grid neutral lines of the microinverters are
correctly connected to the neutral of the grid.
301 Hardware Error Code 301
1. If the alarm occurs accidentally and the microinverter can still function
normally, no special treatment is required.
2. If the alarm occurs frequently and cannot be restored, contact your
dealer or Hoymiles Technical Service Center.
302 Hardware Error Code 302
1. If the alarm occurs accidentally and the microinverter can still function
normally, no special treatment is required.
2. If the alarm occurs frequently and cannot be restored, contact your
dealer or Hoymiles Technical Service Center.
303 Hardware Error Code 303
1. If the alarm occurs accidentally and the microinverter can still function
normally, no special treatment is required.
2. If the alarm occurs frequently and cannot be restored, contact your
dealer or Hoymiles Technical Service Center.
304 Hardware Error Code 304
1. If the alarm occurs accidentally and the microinverter can still function
normally, no special treatment is required.
2. If the alarm occurs frequently and cannot be restored, contact your
dealer or Hoymiles Technical Service Center.
305 Hardware Error Code 305
1. If the alarm occurs accidentally and the microinverter can still function
normally, no special treatment is required.
2. If the alarm occurs frequently and cannot be restored, contact your
dealer or Hoymiles Technical Service Center.
306 Hardware Error Code 306
1. If the alarm occurs accidentally and the microinverter can still function
normally, no special treatment is required.
2. If the alarm occurs frequently and cannot be restored, contact your
dealer or Hoymiles Technical Service Center.
307 Hardware Error Code 307
1. If the alarm occurs accidentally and the microinverter can still function
normally, no special treatment is required.
2. If the alarm occurs frequently and cannot be restored, contact your
dealer or Hoymiles Technical Service Center.
308 Hardware Error Code 308
1. If the alarm occurs accidentally and the microinverter can still function
normally, no special treatment is required.
2. If the alarm occurs frequently and cannot be restored, contact your
dealer or Hoymiles Technical Service Center.
309 Hardware Error Code 309
1. If the alarm occurs accidentally and the microinverter can still function
normally, no special treatment is required.
2. If the alarm occurs frequently and cannot be restored, contact your
dealer or Hoymiles Technical Service Center.
310 Hardware Error Code 310
1. If the alarm occurs accidentally and the microinverter can still function
normally, no special treatment is required.
2. If the alarm occurs frequently and cannot be restored, contact your
dealer or Hoymiles Technical Service Center.
311 Hardware Error Code 311
1. If the alarm occurs accidentally and the microinverter can still function
normally, no special treatment is required.
2. If the alarm occurs frequently and cannot be restored, contact your
dealer or Hoymiles Technical Service Center.

© 2021 Hoymiles Power Electronics Inc. All rights reserved. 16
Three-phase Microinverter HMT-1800/2250 Troubleshooting
6.2 Status LED Indicator
The LED ashes ve times at startup. All green ashes (1s gap) indicate normal startup.
LED
(1) Startup Process
• Five green flashes (0.3s gap): Startup success
• Five red flashes (0.3s gap): Startup failure
(2) Running Process
• Fast green flashing (1s gap): Producing power.
• Slow green flashing (2s gap): Producing power, but one input is abnormal.
• Slow green flashing (4s gap): Producing power, but there is no communication with DTU.
• Red flashing (1s gap): Not producing power, AC grid fault (voltage or frequency out of range).
• Red flashing (0.5s gap): Non-grid abnormality fault.
(3) Other Status
• Alternating red and green flashing: Firmware is corrupted.

© 2021 Hoymiles Power Electronics Inc. All rights reserved. 17
Three-phase Microinverter HMT-1800/2250 Troubleshooting
6.3 On-site Inspection (for qualied installers only)
To troubleshoot an inoperable microinverter, follow the steps mentioned below.
1Verify 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.
3Check 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.
6Verify 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.
6.4 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.
Each branch should provide a circuit breaker, but a central protection unit is not required.
6.5 Replace Microinverter

© 2021 Hoymiles Power Electronics Inc. All rights reserved. 18
Three-phase Microinverter HMT-1800/2250 Troubleshooting
a. How to remove the microinverter.
• De-energize the AC branch circuit breaker.
• Remove the PV panel from the racking and cover the panel.
• Use a meter to measure and make sure that there is no current flowing in the DC wires between the
panel and the microinverter.
• Use the DC disconnect tool to remove the DC connectors.
• Use the AC disconnect tool to remove the AC connectors.
• Unscrew the fixing screw on the top of the microinverter and remove the microinverter from the PV
racking.
b. How to replace the microinverter:
• Please record down the new microinverter’s SN.
• Please make sure that the AC branch circuit breaker is off, and follow the microinverter installation
steps to install the replacement unit.
• Go to the S-Miles Cloud (Hoymiles Monitoring Platform (if the customer already registered this plant
online), access the “Device List” page and find the device that you just replaced. Click the “Edit” button
on the right side of the page and select “Replace Device”. Input the new microinverter's SN and click
“OK” to complete the plant changes.

© 2021 Hoymiles Power Electronics Inc. All rights reserved. 19
Three-phase Microinverter HMT-1800/2250 Decommissioning
7. Decommissioning
7.1 Decommissioning
Disconnect the microinverter from the DC input and AC output; remove all connection cables from the micro-
inverter; remove the microinverter from the frame.
Pack the microinverter in the original packaging, or use a carton box that can support 5kg of weight and can
be fully closed if the original packaging is no longer available.
7.2 Storage and Transportation
Hoymiles packages and protects individual components by using suitable means to facilitate the transport
and subsequent handling. Transportation of the equipment, especially by road, must be carried out by using
means that are suitable for protecting the components (in particular, the electronic components) from vio-
lence, shocks, humidity, vibration, etc. Please dispose of the packaging elements in appropriate ways to avoid
unforeseeable injury.
It is the customer’s responsibility to examine the condition of the components transported. Upon receiving
the microinverter, it is necessary to check the container for any external damage and verify the receipt of all
items. Call the delivery carrier immediately if damage is detected or components are missing. If inspection
reveals damage to the microinverter, contact the supplier or authorized distributor for a repair/return deter-
mination and instructions regarding the process.
The microinverter storage temperature is -40°C - +85°C.
7.3 Disposal
• If the equipment is not used immediately or is stored for long periods, ensure that it is correctly
packed. The equipment must be stored in well-ventilated indoor areas that do not have characteris-
tics that might damage the components of the equipment.
• Conduct a complete inspection when restarting after a long time or prolonged cessation of use.
• For scrapped equipment which is potentially harmful to the environment, please dispose of the equip-
ment properly and in accordance with the regulations in force in the country of installation.