- Solar and energy
- Solar inverter
2021
Huawei inverter 2021: the AFCI self-check failed
Risk level
Critical
Stop using the equipment and contact a professional.
Urgency
Immediate
Quick answer
Huawei alarm 2021 means the AFCI self-check failed. The deciding evidence is whether 2021 is an AFCI self-check failure rather than a 2002 arc event, plus firmware/model and recurrence count. This is an installer-grade electrical alarm: do not infer or buy a component from the ID alone.
Safety first
What to do now
- Preserve the exact alarm context
Save a screenshot of 2021 with timestamp, cause ID, inverter model/serial, firmware, operating power, affected string/MPPT/phase and weather. Do not clear the alarm first.
- Collect the safe discriminator
Leave generation stopped and keep away from PV/DC equipment. Do not clear AFCI, restart repeatedly or touch connectors; an arc or failed arc-protection path can create fire risk. Record whether 2021 is an AFCI self-check failure rather than a 2002 arc event, plus firmware/model and recurrence count; do not change several settings or circuits at once.
- Respect the electrical stop boundary
Do not treat a cleared alarm as a repair. The named arc/AFCI path must be inspected and proven before generation resumes.
What you must never do
- Do not attempt this professional task: Measured installer handoff for 2021
What a technician must be able to justify
A technician is coming
These are the steps they must carry out and show you. Tick them as they work: if steps are skipped, do not accept a part swap.
These are not instructions for opening or handling the equipment yourself. They are the checks that should support a technical conclusion.
Measured installer handoff for 2021
What they doRun the exact model’s AFCI self-test and firmware checks without disabling protection; verify the detection path before clearing or returning the inverter to service.
Before accepting a part or repair
Nothing has been shown yet. Do not accept a part swap based on the code alone.
Where this code applies
A code is meaningful only inside the right product and version context.
Primary scope
- System
- Solar and energy
- Brand
- Huawei
- Product type
- Solar inverter
Known code variants
- alarma Huawei 2021
- alarme Huawei 2021
- allarme Huawei 2021
- erreur SUN2000 2021
- error SUN2000 2021
- errore SUN2000 2021
- Huawei alarm 2021
- Huawei inverter 2021
- Huawei Wechselrichter 2021
- inversor Huawei 2021
- inverter Huawei 2021
- onduleur Huawei 2021
- SUN2000 error 2021
- SUN2000 Fehler 2021
What it means
Huawei’s official inverter alarm reference defines 2021 as a condition in which the AFCI self-check failed. It reports a controller/protection state, not a universal failed part. Record whether 2021 is an AFCI self-check failure rather than a 2002 arc event, plus firmware/model and recurrence count. The next proof is measured: Run the exact model’s AFCI self-test and firmware checks without disabling protection; verify the detection path before clearing or returning the inverter to service.
Warnings and stop conditions
- Criticalsource verified
A DC arc can cause fire and PV conductors remain energised in daylight. Keep clear, leave the protected system stopped and call a qualified PV installer; call emergency services for smoke, flame or burning smell.
Evidence: Huawei Inverter Alarm Reference
Sources and technical references
- 1
Huawei Inverter Alarm Reference
Huawei Digital Power · 2025 · official_doc
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