Huawei SUN2000 Error Code Reference

Complete reference for Huawei SUN2000 error codes, including causes, corrective actions, and how to locate alerts in FusionSolar and alarmg_history logs.

When a Huawei SUN2000 inverter detects a fault, it records an error code in the alarmg_history log with a precise start and end timestamp. The same codes surface as alerts in the FusionSolar app under the event and alarm log. Knowing what each code means — and how urgently you need to act — lets you resolve issues before they escalate into equipment damage or safety hazards.

Error code table

Code	Name	Cause & Action
2062	Low Insulation Resistance	Damaged cable or panel insulation. Commonly appears during or after rain, when moisture reveals insulation defects. Inspect all DC wiring and panel frames for physical damage.
313	Low Insulation Resistance (older models)	Insulation resistance below 100 kΩ. Used on 8–28 KTL and 33–42 KTL series; functionally equivalent to code 2062 on newer series. Apply the same inspection procedure.
301	Abnormal Grid Voltage	Grid voltage is above or below the acceptable range. Check the supply transformer and contact your grid operator if the condition persists.
2001	DC String Reverse	Panel polarity is reversed — the positive and negative DC conductors have been swapped. Correct wiring at the string combiner or MC4 connectors.
2064	Device Fault	Internal inverter error with no single external cause. Requires deep diagnostics using dsp_log data; contact your service partner.
2039	Fan Fault	Cooling fan has failed. The inverter will overheat without airflow, risking damage to IGBT power switches. Replace the fan immediately.

Codes 2039, 2062, and 313 require immediate action. A failed fan (2039) causes rapid thermal damage to power components. Low insulation resistance (2062 / 313) indicates a shock and fire hazard — do not resume operation until the fault is identified and repaired.

Reading error codes in practice

Error codes in alarmg_history include the exact time the alarm started and ended. If you see code 2062 appearing repeatedly for short windows during rainy periods and clearing when weather improves, that pattern points to moisture ingress rather than a permanently damaged cable. Use this timestamp data as evidence when filing claims with your grid operator or pursuing warranty repairs.

For code 2064 (Device Fault), retrieve the dsp_log file via Modbus FC 0x41 and share it with your Huawei service partner. The oscillography data in dsp_wave_data can help distinguish an internal component failure from an external surge event such as a nearby lightning strike.

Frequently asked questions

Why does code 2062 appear only during rain?

Insulation resistance is measured between the PV array conductors and protective earth. When insulation is intact, this resistance is very high — well above the 100 kΩ threshold. Water ingress through micro-cracks in cable sheathing, damaged panel junction boxes, or corroded MC4 connectors lowers that resistance dramatically. Dry conditions keep the resistance artificially high, masking the defect. Rain reveals it. If code 2062 clears reliably once the weather dries out, inspect all outdoor DC connections and cable runs for signs of moisture penetration.

What is the difference between code 313 and code 2062?

Both codes signal the same underlying condition: insulation resistance has fallen below 100 kΩ. The difference is generational. Code 313 is used by older SUN2000 models in the 8–28 KTL and 33–42 KTL series (V2 generation). Code 2062 is the equivalent on newer series. If your inverter reports code 313, apply the same diagnostic and repair steps as you would for 2062 — the fault and the urgency are identical.

How do I find error codes in FusionSolar?

Open the FusionSolar app and navigate to your plant. Select the inverter, then open the Event Log or Alarm section (the label varies slightly by app version). Each entry shows the error code, alarm name, start time, and end time. For a complete historical record including codes from months ago, use the Export Log function in FusionSolar or retrieve the alarmg_history file directly from the inverter via Modbus FC 0x41.