Hoymiles HMT-1800 Series User manual

User Manual
Three-phase Microinverter HMT-1800/2250
Version 1.0 ( 2020)EN

About Microinverter
This system is composed of a group of Three-Phase Microinverters that convert direct current (DC) into
alternating current (AC) and feeds it into the public grid. The system is designed for the incorporation of one
Microinverter for six photovoltaic modules.
Each Microinverter works independently that guarantees the maximum power generation of each photovoltaic
module. This setup enables user to control the production of a single photovoltaic module directly, consequently
improving the exibility 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, only qualied technician, who has received training or has demonstrated skills can install and
maintain this Microinverter under the guide of this document.
Other Information
Product information is subject to change without notice. User manual will be updated frequently, please refer to
Hoymiles ofcial website at www.hoymiles.com for the latest version.
© 2020 Hoymiles Power Electronics Inc. All rights reserved. 01
Three-phase Microinverter HMT-1800/2250

1. Important Notes 3
1.1 Product Range 3
1.2 Microinverter Accessories 3
1.3 Target Group 3
1.4 Symbols Used 3
1.5 Radio Interference Statement 3
2. About Safety 4
2.1 Important Safety Instructions 4
2.2 Explanation of Symbols 5
3. About Product 6
3.1 About Three-Phase Microinverter 6
3.2 About Sub-1G technology 6
3.3 Highlights 6
3.4 Terminals Introduction 7
3.5 Dimension 7
4. About Function 8
4.1 Module Compatibity 8
4.1 AC Branch Circuit Capacity 8
4.1 Position and Space Required 8
5. About Installation 9
5.1 Accessories 9
5.2 Pre-installation 9
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 qualied 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 Efciency, 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
CONTENTS
© 2020 Hoymiles Power Electronics Inc. All rights reserved. 02
Three-phase Microinverter HMT-1800/2250

1. Important Notes
1.1 Product Range
This manual describes the assembly, installation, commissioning, maintenance and failure search of the following
model of Hoymiles Three-Phase Microinverter:
· HM T-180 0 - 6T
· HMT-2250-6T
*Note: “1800” means 1800W, “2250” means 2250W.
1.2 Microinverter Accessories
Hoymiles HMT series three-phase microinverter need to be used with the special three-phase system accessories,
including three-phase bus cable, unlock tool, end cap, etc. Please nd more information in chapter 4.1.
A DTU is required if the user wants to see the information and solar production on Hoymiles Monitoring System.
1.3 Target Group
This manual is only for qualied technician, who has been trained or has demonstrated skills can install and maintain
this Microinverter under the guide of this document for safety purpose.
1.4 Symbols Used
The safety symbols in this user manual are show as below.
Symbol Usage
Indicates a hazardous situation that can result in deadly electric shock hazards, other
serious physical injury, or re hazards.
Indicates directions which must be fully understood and followed in entirety in order
to avoid potential safety hazards including equipment damage or personal injury.
Indicates this points out that the described operation must not be carried out. The
reader should stop, use 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 can provide reasonable pro-
tection against harmful energy. However, if not installed according to the instructions, the microinverter may cause
harmful interference to radio equipment. There is no guarantee that the interference will not occur in a particular
installation.
To conrm that the radio or television reception is interfered by this equipment, you can turn the equipment off and
on. If this equipment does cause harmful interference to the radio or television equipment, please try to correct the
interference by 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 the shield between the microinverter and the receiving antenna, such as metal / concrete roof.
4) Contact your dealer or an experienced radio/TV technician for help.
© 2020 Hoymiles Power Electronics Inc. All rights reserved. 03
Three-phase Microinverter HMT-1800/2250 Important Notes

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 inverter. The
installer must read and follow all instructions, cautions and warnings in this installation manual.
• All operations including transport, installation, start-up and maintenance, must be carried out by qualied,
trained personnel.
• Before installation, check the unit to ensure free of any transport or handling damage, which could affect in-
sulation integrity or 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 lead to serious safety and shock hazards or equipment damage.
• Before connecting the Microinverter to the power distribution grid, contact the local power distribution grid
company to get 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 Over current Protection
Devices (OCPD).
• Usually only one photovoltaic module can be connected to one input of the inverter. Do not connect batteries
or other sources of power supply. The inverter can be used only if all the technical characteristics are
observed and applied.
• Do not install the equipment in adverse environment conditions such as ammable, explosive, corrosive,
extreme high or low temperature, and humid. Do not use the equipment when the safety devices do not work
or disabled.
• Use personal protective equipment, including gloves and eye protection during the installation.
• Inform the manufacturer about non-standard installation conditions.
• Do not use the equipment if any operating anomalies are found. Avoid temporary repairs.
• All repairs should be carried out using only 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 commercial components are delegated to their respective manufacturers.
• Anytime the inverter has been disconnected from the public network, please be extremely caution as some
components can retain charge sufcient to create a shock hazard. Prior to touching any part of the inverter
please ensure surfaces and equipment are under touch safe temperatures and voltage potentials before pro-
ceeding.
• Hoymiles accepts No liability for damage from incorrect or improper operation.
• Electrical Installation & Maintenance shall be conducted by licensed electrician and shall comply with Local
Wiring Rules.
© 2020 Hoymiles Power Electronics Inc. All rights reserved. 04
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 collected separately and returned to an approved re-
cycling 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 (20cm) 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 inverter can become hot during operation. Avoid contact with metal surfaces during
operation.
CE mark
The inverter complies with the requirements of the Low Voltage Directive for the Euro-
pean Union.
Read manual rst
Please read the installation manual rst before installation, operation and maintenance.
© 2020 Hoymiles Power Electronics Inc. All rights reserved. 05
Three-phase Microinverter HMT-1800/2250 About Safety

3. About Product
3.1 About Three-Phase Microinverter
The world’s rst three-phase microinverter with Reactive Power Control, 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 differ from, say, 2.4GHz technologies in that they
have substantially larger range and better interference suppression performance.
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, meets the require- ments of EN50549-1:2019, VDE-AR-N 4105:2018,
TOR Erzeuger : 2019-12, etc.
• The Sub-1G wireless solution enables the stable communication when installed for commercial and industrial
stations.
© 2020 Hoymiles Power Electronics Inc. All rights reserved. 06
Three-phase Microinverter HMT-1800/2250 About Product
Range of Sub-1GHz wireless: Unlike WiFi and Zigbee, who 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 2.4Ghz spectrum.
Interference: Sub-1GHz wireless can handle interference better. This is because they operate
on a lower frequency which can communicate better between PV modules and
rooftops, and especially useful in an industrial or commercial PV power plant. Thus,
the communication between the microinverters and the DTUs will be more stable.
Lower Power Consumption: Sub-1GHz wireless typically use less power than WiFi or Zigbee.
Because of the long range and better interference suppression performance, Sub-1GHz networking is particularly
well-suited to rooftop PV power stations.

3.4 Terminals Introduction
3.5 Dimension(mm)
Object Description
A Sub-1G Wireless Terminal
B DC Connectors
C AC Connector
326
245
288
146.5
140
500
© 2020 Hoymiles Power Electronics Inc. All rights reserved. 07
Three-phase Microinverter HMT-1800/2250 About Product
CAB

4.3 Position and Space Required
Please install the Microinverter and all DC connections under the PV module to avoiding direct sunlight, rain exposure,
snow layup, UV etc. Also, the silver side of the microinverter should be up and face to the PV module.
Allow a minimum of 2 cm of space around the microinverter enclosure to ensure ventilation and heat dissipation.
HM T-180 0 HMT-2500 Maximum over current
protection device (OCPD)
Maximum number per
12AWG branch 7(@230Vac) 6(@230Vac) 20A
Maximum number per
10AWG branch 11(@230Vac) 9(@230Vac) 30A
4. Installation Preparation
4.1 Module Compatibity
Hoymiles HMT series HMT-1800/HMT-2250 are compatible with most 60-cell and 72-cell PV modules. For other
types of PV modules, please ensure that they are electrically paired with Hoymiles microinverter. Please see the Tech-
nical Data page of this user manual to get more information.
4.2 AC Branch Circuit Capacity
Hoymiles HMT-1800/HMT-2250 can be used with 12AWG or 10AWG AC bus cable and the AC bus connector which
are provided by Hoymiles. When preparing, do not exceed the limits of maximum number of microinverters per
12AWG or 10AWG AC branch shown as below.
© 2020 Hoymiles Power Electronics Inc. All rights reserved. 08
Three-phase Microinverter HMT-1800/2250 About Function

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 Unlock Tool
C3P-AC Bus Connector
D 3P-Bus Connector Unlock Tool
E3P-AC Sub Cap
FM8*25 screws
G DC Extension Cable,1m
H 3P-AC Bus Cable, 12/10 AWG Optional
*Note: All accessories above are not included by the package, will need to be purchased separately. Please contact
our sales representative for the price (M8 screws will need to be prepared by installer-self).
• Use the 3P-Bus connector unlock tool to
unlock the connector upper cover;
5.2 Pre-installation
A ) Plan the cable length to allow the bus cable align with each PV module.
B ) Install the AC bus end cap:
© 2020 Hoymiles Power Electronics Inc. All rights reserved. 09
Three-phase Microinverter HMT-1800/2250 About Installation

• Loose the ve screws with the
screwdriver. Untighten the nut shown as
picture and remove the extra cable.
• Slightly screw the nut back to the body,
plug in the 3P-AC bus end cap and tighten
the nut.
• Plug the upper cover back to the 3P-AC
bus connector.
A) Attach the 3P-AC Bus Cable with the
mounting rail, and x the cable by tie
wraps.
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 it clicks.
C ) If any bus port is vacant, please plug the
3P-AC sub cap into the port to protect it
from dust and walter.
Note: Under the circumstance that need to remove
the inverter AC cable from 3P-AC bus connector,
please use the 3P-AC connector unlock tool and
insert the tool into the side of AC port to remove.
5.3 Installation Steps
Note: The following installation steps are based on the 2*3 installation of PV modules, other installations may require the use of
more accessories.
Step 1. Fix Microinverter on the 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 and under the PV module. Allow a minimum of 2cm around the microin-
verter enclosure to ensure ventilation and heat dissipation.
Step 2. Complete the AC Connection
© 2020 Hoymiles Power Electronics Inc. All rights reserved. 10
Three-phase Microinverter HMT-1800/2250 About Installation

A ) Prepare the 3P-AC End Cable with the
proper length, insert one side of the cable
into the seal nut. Match the L1, L2, L3, N
and Ground line into the slot accordingly.
Tighten the screws, and then tighten the
cap back to the connector. Plug the upper
cover back to 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.
Step 3. Install AC End Cable
A ) Peel the removable serial number label
from each microinverter (shown as
picture).
B ) Afx the serial number label to the
respective location on the installation map
Step 4. Create an Installation Map
A ) Mount the PV modules above the
microinverter.
B ) Connect the PV modules’ DC cables to the
DC input side of the microinverter.
Step 5. Connect PV Modules
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 minutes.
Step 6. Energize the System
Refer to the DTU User Manual or DTU Quick Install Guide, and Quick Installation Guide for HMP Online Registration
to install the DTU and set up monitoring system.
Step 7. Monitoring System Set Up
© 2020 Hoymiles Power Electronics Inc. All rights reserved. 11
Three-phase Microinverter HMT-1800/2250 About Installation
N
PE
L3
L2
L1
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

6. Troubleshooting
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 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 Of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 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.
© 2020 Hoymiles Power Electronics Inc. All rights reserved. 12
Three-phase Microinverter HMT-1800/2250 Troubleshooting

142 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 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.
144 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 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 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 Power grid outage Please check whether there is a power grid outage.
148 Grid disconnection Please check whether the AC switch or AC wiring is normal.
149 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
difference 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.
© 2020 Hoymiles Power Electronics Inc. All rights reserved. 13
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 within the normal range,
contact your dealer or Hoymiles technical support.
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 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.
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 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.
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.
217 Port 5 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.
218 Port 6 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.
219 PV-5 & PV-6
abnormal wiring
Please check whether the DC connections on port 5 and 6 are
correct.
© 2020 Hoymiles Power Electronics Inc. All rights reserved. 14
Three-phase Microinverter HMT-1800/2250 Troubleshooting

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.
© 2020 Hoymiles Power Electronics Inc. All rights reserved. 15
Three-phase Microinverter HMT-1800/2250 Troubleshooting

6.2 Status LED Indicator
The LED ashes ve times at start up. All green ashes (1s gap) indicate normal start up.
(1) Start-up Process
• Flashing green ve times (0.3s gap): Start-up success
• Flashing Red ve times (0.3s gap): Start-up failure
(2) Run Process
• Flashing Fast Green (1s gap): Producing power.
• Flashing Slow Green (2s gap): Producing power but one input is abnormal.
• Flashing Slow Green (4s gap): Producing power but there is no communication with DTU.
• Flashing Red (1s gap): Not producing power AC grid invalid (Voltage or frequency out of range).
• Flashing Red (0.5s gap): There is a fault except the abnormality of grid.
(3) Other Status
• Flashing Red and Green alternately: Firmware is corrupted.
© 2020 Hoymiles Power Electronics Inc. All rights reserved. 16
Three-phase Microinverter HMT-1800/2250 Troubleshooting
LED

6.3 On-site Inspection (For qualied installer only)
To troubleshoot an inoperable microinverter, follow the steps in the order shown.
1Verify the utility voltage and frequency are within ranges shown in the in appendix Technical Data
of this microinverter.
2
Check the connection to the utility grid. Verify utility power is present at the inverter 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 ve short LED ashes.
3Check the AC branch circuit interconnection between all the microinverters. Verify each inverter is
energized by the utility grid as described in the previous step.
4 Make sure that any AC breaker are functioning properly and are closed.
5 Check the DC connections between the microinverter and the PV module.
6Verify the PV module DC voltage is within the allowable range shown in appendix Technical Data of
this manual.
7 If the problem persists, please call Hoymiles customer support.
Do not try to repair the microinverter. If the 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 are responsible to report any
anomalies.
2. Always use the personal protective equipment provided by the employer when carry out the maintenance operation.
3. During normal operation, check that the environmental and logistic conditions are correct. Make sure that the condi-
tions 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 normal conditions after the fault removed.
5. Conduct an annual inspection on 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 preserving
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 (power
switch open) and the photovoltaic modules obscured or isolated, unless otherwise indicated.
For cleaning, do not use rags made of lamentary material or corrosive products that may corrode
parts of the equipment or generate electrostatic charges.
Avoid temporary repairs. All repairs should be carried out using only genuine spare parts.
Each branch should provide a circuit breaker, but no need for central protection unit.
© 2020 Hoymiles Power Electronics Inc. All rights reserved. 17
Three-phase Microinverter HMT-1800/2250 Troubleshooting

6.5 Replace Microinverter
a. How to remove the Microinverter.
• De-energize the AC branch circuit breaker.
• Remove the PV panel from the racking, and cover the panel.
• Using a meter to measure and make sure there is no current owing in the DC wires between panel and
microinverter.
• Use the DC disconnect tool to remove the DC connectors.
• Use the AC disconnect tool to remove the AC connectors.
• Un-screw the xing 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 the AC branch circuit breaker if off, and following the Microinverter installation steps to
install the replacement unit.
• Go to the monitoring platform (if customer already register this station online), please access the “Device List”
page and nd the device that you just replaced. Please click the edit button on the right side of the page, and
select “Device Replace”. Input the new Microinverter’s SN and click “OK” to complete the station changes.
© 2020 Hoymiles Power Electronics Inc. All rights reserved. 18
Three-phase Microinverter HMT-1800/2250 Troubleshooting

7. Decommissions
7.1 Decommissions
Disconnect the inverter from DC input and AC output; remove all connection cable from the Microinverter; remove
the Microinverter from the frame.
Please pack the Microinverter with the original packaging, or use the carton box that can afford 5kg 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 using suitable means to make the transport and subsequent
handling easier. Transportation of the equipment, especially by road, must be carried out by suitable ways for protect-
ing the components (in particular, the electronic components) from violent, shocks, humidity, vibration, etc. Please
dispose the packaging elements in appropriate ways to avoid unforeseen injury.
It is the customer’s responsibility to examine the condition of the components transported. Once receiving the Micro-
inverter, it is necessary to check the container for any external damage and verify receipt of all items. Call the deliv-
ering carrier immediately if damage or shortage is detected. If inspection reveals damage to the inverter, contact the
supplier, or authorized distributor for a repair/return determination and instructions regarding the process.
The microinverter storage temperature is -40℃ ~ +85℃.
7.3 Disposal
• If the equipment is not used immediately or is stored for long periods, check that it is correctly packed. The
equipment must be stored in well-ventilated indoor areas that do not have characteristics that might damage
the components of the equipment.
• Take a complete inspection when restarting after a long time or prolonged stop.
• Please dispose the equipment properly after scrapping, which are potentially harmful to the environment, in
accordance with the regulations in force in the country of installation.
© 2020 Hoymiles Power Electronics Inc. All rights reserved. 19
Three-phase Microinverter HMT-1800/2250 Decommissions