Huawei · PV inverters · Huawei SUN2000-KTL-M1 (three-phase inverter, 3–10 kW, battery-ready)
Alarm 2009String Short-Circuited to Ground
Name in the manufacturer's documentation (fault list): String Short-Circuited to Ground
[1]
In plain words (editorial)
A PV string is short-circuited to ground, or damp air around the PV array has reduced its insulation to ground. If auto-recovery from this protection is enabled, the alarm clears automatically once the fault is gone.
When to call a service technician: Have an installer measure and repair the PV cable insulation. Contact your installer or Huawei technical support.
✎ editorial – written from the cited sources, not a manufacturer statement. Status: draft.
For technicians
Possible causes (source text)
- The pv array is short-circuited to the ground.[2]
- The ambient air of the pv array is damp and the insulation between the pv array and the ground is poor.[3]
- The negative pv terminal of mppt1 is short-circuited to the ground.[4]
- The ambient air of the negative pv terminal of mppt1 is damp, and the insulation between the circuit and the ground is poor.[5]
Steps given by the manufacturer (source text)
- For the inverter equipped with an automatic dc disconnect switch, check the dc switch status. if the dc switch points to 'trip', contact your vendor or technical support and then go to the next step.[6]
- Remove the positive and negative pv cables on the inverter. use a megohmmeter to measure the resistance of each pv cable to the ground in sequence. if a short circuit occurs or the insulation resistance is low, check whether the pv cable of the faulty route is damaged and rectify the fault.[7]
- If no faults are detected in the pv cables using the megohmmeter, check each pv cable for damage and rectify the fault.[8]
- After the fault is rectified, manually clear the alarm. if the fault persists, contact your vendor or technical support.[9]
- Check the resistance between the negative pv terminal of mppt1 and the ground. if a short circuit or insufficient insulation is found, rectify it.[10]
- If auto recovery from string-to-ground short-circuit protection is disabled, check and rectify the preceding faults, and manually clear the alarm.[11]
Notes from the documentation
- If auto recovery from string-to-ground short-circuit protection is enabled, the alarm will be automatically cleared after fault recovery.[12]
⚠ Work on refrigerant circuits, mains electricity and PV DC wiring is for qualified technicians only.
The Polish page has more detail (plain-language explanation, safe checks, guides): Read in Polish →
Sources
Every statement has a footnote to the document and PDF page. “Quote verified” means the quote was found automatically in the text of that page.
- [1] Inverter Alarm Reference (Issue 14, 2026-06-15) (EDOC1100345192 Issue 14) , p. 23 official manufacturer document quote verified
2009 String Short-Circuited to Ground
- [2] Inverter Alarm Reference (Issue 14, 2026-06-15) (EDOC1100345192 Issue 14) , p. 23 official manufacturer document quote verified
the pv array is short-circuited to the ground.
- [3] Inverter Alarm Reference (Issue 14, 2026-06-15) (EDOC1100345192 Issue 14) , p. 23 official manufacturer document quote verified
the ambient air of the pv array is damp and the insulation between the pv array and the ground is poor.
- [4] Inverter Alarm Reference (Issue 14, 2026-06-15) (EDOC1100345192 Issue 14) , p. 23 official manufacturer document quote verified
the negative pv terminal of mppt1 is short-circuited to the ground.
- [5] Inverter Alarm Reference (Issue 14, 2026-06-15) (EDOC1100345192 Issue 14) , p. 23 official manufacturer document quote verified
the ambient air of the negative pv terminal of mppt1 is damp, and the insulation between the circuit and the ground is poor.
- [6] Inverter Alarm Reference (Issue 14, 2026-06-15) (EDOC1100345192 Issue 14) , p. 25 official manufacturer document quote verified
for the inverter equipped with an automatic dc disconnect switch, check the dc switch status. if the dc switch points to 'trip', contact your vendor or technical support and then go to the next step.
- [7] Inverter Alarm Reference (Issue 14, 2026-06-15) (EDOC1100345192 Issue 14) , p. 25 official manufacturer document quote verified
remove the positive and negative pv cables on the inverter. use a megohmmeter to measure the resistance of each pv cable to the ground in sequence. if a short circuit occurs or the insulation resistance is low, check whe…
- [8] Inverter Alarm Reference (Issue 14, 2026-06-15) (EDOC1100345192 Issue 14) , p. 25 official manufacturer document quote verified
if no faults are detected in the pv cables using the megohmmeter, check each pv cable for damage and rectify the fault.
- [9] Inverter Alarm Reference (Issue 14, 2026-06-15) (EDOC1100345192 Issue 14) , p. 25 official manufacturer document quote verified
after the fault is rectified, manually clear the alarm. if the fault persists, contact your vendor or technical support.
- [10] Inverter Alarm Reference (Issue 14, 2026-06-15) (EDOC1100345192 Issue 14) , p. 25 official manufacturer document quote verified
check the resistance between the negative pv terminal of mppt1 and the ground. if a short circuit or insufficient insulation is found, rectify it.
- [11] Inverter Alarm Reference (Issue 14, 2026-06-15) (EDOC1100345192 Issue 14) , p. 25 official manufacturer document quote verified
if auto recovery from string-to-ground short-circuit protection is disabled, check and rectify the preceding faults, and manually clear the alarm.
- [12] Inverter Alarm Reference (Issue 14, 2026-06-15) (EDOC1100345192 Issue 14) , p. 25 official manufacturer document quote verified
if auto recovery from string-to-ground short-circuit protection is enabled, the alarm will be automatically cleared after fault recovery.