Your Huawei SUN2000 inverter has stopped producing power, is showing a red LED indicator, or has triggered an alarm in the FusionSolar app. Every alarm ID corresponds to a specific condition the inverter has detected. Some clear themselves within minutes. Others need a qualified electrician.
Modern Huawei SUN2000 inverters are screenless. There is no LCD display showing error codes. Instead, faults are communicated through the LED indicators on the front panel and through alarm notifications in the Huawei FusionSolar app. This is different from most other inverter brands, and it means you need the app or a WiFi connection to see specific alarm details.
This guide applies to the full Huawei SUN2000 residential and light commercial range installed in Australia: SUN2000-L1 series (single-phase, 2–6kW), SUN2000-M0 series (three-phase, 3–10kW), SUN2000-M1 series (three-phase, 5–25kW), SUN2000-M2 series (three-phase, 12–20kW), and LUNA2000 battery systems paired with compatible SUN2000 inverters.
Last reviewed: April 2026. Alarm ID lists verified against current Huawei FusionSolar documentation, SUN2000 user manual (Issue 28, 2025), and FusionSolar app alarm descriptions. Contact PSW Life Support if your alarm is not listed or the recommended steps do not resolve the issue.
Contents
How Huawei alarm severities work
Huawei classifies every alarm into one of three severity levels. Understanding the severity tells you how urgently you need to act.
- Major: The inverter is faulty. Output power has decreased significantly or the inverter has stopped feeding into the grid entirely. These alarms require attention and often need professional service.
- Minor: A component is faulty, but the inverter may still be generating power. Production could be reduced. Monitor the alarm and arrange service if it persists.
- Warning: The inverter is working normally, but output power has decreased or some features are unavailable due to external factors (e.g., high grid voltage, low sunlight, high temperature). Most warnings clear automatically.
How to find your alarm ID
FusionSolar app (primary method): Download the Huawei FusionSolar app (iOS or Android). Log in and navigate to your plant. Tap on the inverter, then check the “Alarm” or “Alerts” section. Active and historical alarms are listed with alarm IDs, timestamps, and descriptions. Set your region to Australia in the app settings.
FusionSolar web portal: Log in at intl.fusionsolar.huawei.com. Navigate to your plant and check the alarm management section.
LED indicators: The inverter’s front panel has three LED indicators. The LED colour and behaviour give you a general status, but you need the FusionSolar app for the specific alarm ID.
Local connection (for first-time setup or WiFi issues): Connect your phone to the inverter’s WLAN hotspot (SSID and password are on the label on the side of the inverter). Open the FusionSolar app and use “Device Commissioning” to access the inverter locally.
Before you look up your alarm: try a restart
Many Huawei alarm IDs resolve with a standard system restart. Before contacting your installer, try this:
- Switch OFF the AC circuit breaker for the inverter (in your switchboard, labelled “Solar” or “Inverter”)
- Switch the DC switch on the bottom of the inverter to the OFF position
- If you have a LUNA2000 battery connected, turn off the battery switch as well
- Wait until all LED indicators on the inverter panel turn off completely
- Switch ON the AC circuit breaker first
- Switch the DC switch to ON
- If applicable, turn the battery switch back on
- Wait for the inverter to complete its start-up sequence. The green LED should begin blinking slowly (indicating grid connection) within a few minutes
If the alarm reappears after the restart, note the exact alarm ID and the time, then look it up below.
Safety notice: Never open the inverter cover or disconnect DC connectors yourself. DC cables from solar panels carry dangerous voltage during daylight hours. All work inside the inverter or on DC wiring is restricted to licensed electricians under Western Australian electrical safety legislation.
PV string and DC alarm IDs (2011–2031)
These alarms relate to the DC side of the system: solar panels, string wiring, and the connection to the inverter.
| Alarm ID | Severity | Description | What to do |
|---|---|---|---|
2011 | Warning | PV string polarity reversed. A PV string is connected with reversed positive and negative | Contact your installer. Wait until the PV string current drops below 0.5A (evening), then switch off the DC switch and correct the polarity. Do not disconnect DC connectors under load |
2012 | Warning | Insufficient modules in PV string. The number of panels in series on one string is fewer than the other strings | Check for a disconnected panel or connector in the affected string. Confirm shading is not reducing the string voltage. If the panel count is intentionally different, verify the open-circuit voltage is within the inverter’s MPPT range |
2021 | Minor | AFCI check failure. The arc fault circuit interrupter self-test has failed | Switch off both the DC and AC switches, wait five minutes, then switch them back on. If persistent, contact your installer. The AFCI module may need service |
2031 | Major | DC arc fault detected. The inverter’s AFCI has detected a potential arc in the DC wiring | ⚠️ Potential fire risk. Contact your installer immediately. Do not restart without professional inspection. Check for loose MC4 connectors, damaged cable insulation, or corroded junction box terminals |
Insulation and earth fault alarm IDs (2063–2065)
These alarms are safety-critical and indicate that current may be leaking from the DC system to earth.
| Alarm ID | Severity | Description | What to do |
|---|---|---|---|
2063 | Major | Low insulation resistance. The insulation between the PV array and earth is below the minimum threshold | Contact your installer. Common causes: moisture in MC4 connectors, DC isolators, or panel junction boxes, damaged cable insulation, or a short circuit between the PV array and ground. More common after rain. To locate the fault, connect each PV string one at a time and check the alarm. If the fault only appears after rain and clears in dry weather, there is a water ingress point that needs to be sealed |
2064 | Major | High residual current / earth leakage. The inverter has detected leakage current exceeding the permitted threshold | Contact your installer. Do not touch uninsulated wires. This is a safety-critical fault. Causes are similar to 2063. The environment may also be damp, causing temporary high leakage. If the alarm clears when conditions dry out but returns after rain, the installation needs inspection |
2065 | Major | Residual current device (RCD) tripped. The internal earth leakage protection has activated | Contact your installer. The RCD threshold is configurable in the FusionSolar app. Enabling “RCD enhancement” can reduce residual current but may cause derating. Do not permanently disable the RCD without engineering approval |
DC voltage alarm IDs (2066–2067)
| Alarm ID | Severity | Description | What to do |
|---|---|---|---|
2066 | Major | DC overvoltage. The PV string voltage exceeds the inverter’s maximum input limit | Contact your installer immediately. This should not occur in a correctly designed system. Do not restart without professional inspection. Possible causes: too many panels in series, a panel bypass diode fault, or extreme cold weather increasing open-circuit voltage |
2067 | Warning | DC undervoltage. The PV string voltage is below the inverter’s minimum operating threshold | Normal at dawn, dusk, during heavy cloud, or rain. If this appears during clear midday conditions, check for shading, a disconnected string, or a tripped DC isolator |
Grid and AC alarm IDs (2068–2090)
These alarms indicate the grid supply is outside the inverter’s permitted operating range. The inverter disconnects to comply with AS 4777.2 and restarts automatically when conditions normalise.
In Perth, alarm IDs 2068 and 2090 are the most common Huawei alarms. Grid voltage on the SWIS network rises during high-solar-export periods, particularly in suburbs with dense rooftop PV.
| Alarm ID | Severity | Description | What to do |
|---|---|---|---|
2068 | Warning | Grid voltage out of range (high). The AC voltage exceeds the inverter’s upper protection limit | Most common alarm in Perth. Usually caused by high network voltage during peak solar export. The inverter restarts automatically when voltage drops. If persistent, your installer can verify the grid code setting, check AC wiring, or request a Western Power network voltage assessment |
2069 | Warning | Grid frequency out of range. The AC frequency has drifted outside the permitted window | Automatic. Rare in WA. If persistent, contact your installer to verify protection settings |
2070 | Warning | Grid loss / island detection. The inverter has detected that the grid is no longer available | Check your switchboard for tripped breakers. Confirm there is no area outage on the Western Power outage map. The inverter will restart automatically once grid supply returns and the reconnection timer expires |
2090 | Warning | Grid voltage high (10-minute average). The sustained average grid voltage exceeds the permitted range | Similar to 2068 but based on a sustained reading. Common in Perth during extended solar export periods. Your installer can adjust the volt-watt response settings or request a network assessment |
Hardware and internal alarm IDs
| Alarm ID | Severity | Description | What to do |
|---|---|---|---|
2002 | Warning | Over-temperature. The inverter’s internal temperature has exceeded the safe operating limit | Check ventilation around the inverter. Clear debris, spider webs, or vegetation. Verify the inverter is not in direct sunlight and has adequate clearance. In Perth, common on 40°C+ days. The inverter will derate before shutting down entirely. Consider a shade structure if this occurs regularly |
2001 | Minor | Internal hardware fault | Restart. If persistent, contact Huawei support or your installer. The inverter may need service or replacement under warranty |
2040 | Minor | Fan fault. The internal cooling fan is not operating correctly | Restart. If the fan is physically obstructed, clear the obstruction. If persistent, the fan may need replacement. Contact your installer |
LUNA2000 battery alarm IDs (3xxx range)
If you have a Huawei LUNA2000 battery system connected to your SUN2000 inverter, you may see additional alarm IDs in the 3xxx range. These relate to the battery management system (BMS), battery voltage, temperature, and communication.
| Alarm ID | Description | What to do |
|---|---|---|
3001 | Battery communication failure. The inverter has lost communication with the LUNA2000 battery | Check the communication cable (CAN bus) between the inverter and battery. Verify the cable is correctly connected at both ends. If the cable is secure, try restarting the battery (switch off, wait two minutes, switch on). If persistent, contact PSW Life Support |
3013 | Battery extension module communication failure. The inverter cannot communicate with a battery expansion module | Check the CAN communication cable between the main battery module and the extension module. Disconnect and reconnect, listening for a firm click. If you have multiple battery towers, try isolating each tower individually to identify which one is faulting. Contact your installer if persistent |
3007 | Battery over-temperature | Check ventilation around the battery. Ensure nothing is blocking airflow. The LUNA2000 must not be exposed to direct sunlight (this is a warranty condition). Contact your installer if persistent |
3008 | Battery under-temperature | Rare in Perth. Lithium batteries will not charge or discharge below approximately 0°C. The battery will resume operation when it warms up |
3009 | Battery voltage abnormal | Contact your installer. The battery voltage may be too high or too low. This could indicate a cell imbalance or BMS fault |
3010 | Battery SOC abnormal | The reported state of charge is inconsistent. The battery may need a full charge-discharge cycle to recalibrate. If persistent, contact your installer |
Huawei LED status indicators
All SUN2000 inverters use three LED indicators on the front panel. Because these inverters are screenless, the LEDs are your first visual diagnostic tool.
| LED indicator | State | Meaning |
|---|---|---|
Indicator 1 (leftmost) | Steady green | Normal grid-tied operation. The inverter is generating power |
Indicator 1 | Slow green blink (long intervals) | The inverter is connected to the grid but not yet generating (start-up, low DC input, or reconnection countdown) |
Indicator 1 | Fast green blink (short intervals) | Communication mode active (WLAN hotspot is on for app connection) |
Indicator 2 (middle) | Steady green | Normal operation |
Indicator 3 (rightmost) | Steady green | Normal operation |
Any indicator | Red | A fault has occurred. Check the FusionSolar app for the specific alarm ID |
All indicators | Off | No power to the inverter. Check that the AC breaker, DC switch, and battery switch (if applicable) are all on |
All indicators | Blink then turn off (30 seconds) | Password reset sequence in progress |
Codes that need immediate professional attention
Most Huawei alarms are either temporary (grid-related warnings) or informational. The following alarm IDs require prompt action from a qualified electrician:
- 2063 (Low insulation resistance) — Earth insulation breakdown. Possible safety risk in the DC wiring or panels
- 2064 (High residual current) — Earth leakage detected. Safety-critical
- 2031 (DC arc fault detected) — Potential fire risk in DC wiring. Do not restart without inspection
- 2066 (DC overvoltage) — PV voltage exceeds the inverter’s maximum. Possible string design error
- 2065 (RCD tripped) — The internal earth leakage protection has activated
For any alarm in this list, contact PSW Life Support or call your original installer.
FusionSolar app and monitoring
The Huawei FusionSolar app is the primary interface for monitoring your system, viewing alarms, and accessing inverter settings. If the app shows no data or your inverter appears offline, the inverter has usually lost its WiFi connection. The solar system continues to generate power normally; only monitoring is affected.
Connecting to your inverter locally:
- Find the WLAN hotspot SSID and password on the label on the side of the inverter
- Connect your phone to the inverter’s WiFi network
- Open the FusionSolar app and go to “Device Commissioning”
- Log in with the initial password and change it on first login
- Resetting the WiFi password: If you have forgotten the login password, you can perform a factory reset of the WLAN credentials by following the physical button sequence on the inverter (turn off AC and DC, wait for LEDs to go off, turn on, wait 90 seconds until slow green blink, turn off again, turn on again, all LEDs blink and turn off after 30 seconds, then reset the password within 10 minutes). This procedure is detailed in the SUN2000 user manual.
- Firmware updates: Huawei can push firmware updates remotely through FusionSolar when the inverter is online. Your installer can also update firmware via the SmartLogger or FusionSolar app during a site visit. The inverter restarts automatically after a firmware upgrade.
Frequently asked questions
My inverter shows alarm 2068 or 2090 every day around midday. Is it broken?
No. These are the most common Huawei alarms in Perth. Under AS 4777.2:2020, your inverter must disconnect when grid voltage exceeds the permitted threshold. This is common in suburbs with high rooftop solar penetration. The inverter restarts automatically when voltage drops. If this is significantly reducing your generation, your installer can verify the grid code settings or request a Western Power network voltage assessment.
My inverter has a red LED but I cannot see an error code on the screen. How do I find the alarm?
Huawei SUN2000 inverters are screenless — there is no LCD display. The alarm details are only available through the FusionSolar app or web portal. Connect your phone to the inverter’s WLAN hotspot (SSID and password on the side label) and open the FusionSolar app, or check at intl.fusionsolar.huawei.com if the inverter is online.
Alarm 2063 (low insulation resistance) appears after rain but clears when dry. Is this serious?
It needs attention. Moisture in MC4 connectors, panel junction boxes, or DC isolators temporarily reduces insulation resistance. While the system recovers when dry, the water ingress point should be found and sealed to prevent the issue worsening. Contact your installer to inspect the DC side.
My LUNA2000 battery shows alarm 3001 (communication failure). Is the battery damaged?
Not necessarily. This is usually a communication cable issue. Check the CAN bus cable between the inverter and battery. Disconnect and reconnect both ends. If the alarm persists, try restarting the battery. If it continues after a cable check and restart, the BMS or inverter communication port may need attention. Contact PSW Life Support.
I have an alarm ID not listed here. What should I do?
Contact PSW Life Support with the alarm ID, your inverter model and serial number, and the approximate time the alarm appeared. We service Huawei inverters across Perth and can diagnose many issues remotely through FusionSolar.
References
- Huawei — FusionSolar portal
Huawei — SUN2000 user manual (Issue 28, 2025)
Huawei — LUNA2000 battery troubleshooting
AS 4777.2:2020 — Grid connection of energy systems via inverters (Part 2: Inverter requirements)
Western Power — Technical Rules and Metering Code
This guide is current as at April 2026. Huawei firmware updates may introduce new alarm IDs or modify existing behaviour. Contact PSW Life Support for the latest information.
