Huawei SUN2000 throws alarm 2062 Low Insulation Resistance every morning or after rain. Where do I start?

The short answer

Treat it as a real insulation fault: check PE first, then test the PV array (and battery rack) to ground.

Plain explanation

From the Huawei manual for the SUN2000 inverter: Set Insulation resistance protection to the minimum value and restart the inverter. Check that the PE cable of the device is correctly connected. The rest of the checklist is below; work through it in order. Installer only: DC and AC work on a live PV system is dangerous, so owners should note the code and call their installer.

Steps from the source

Set Insulation resistance protection to the minimum value and restart the inverter
Check that the PE cable of the device is correctly connected
Check the PV array's output-to-ground impedance. Short circuit or inadequate insulation detected? Rectify it
Battery rack connected? Send a shutdown command to devices on the same DC bus and start insulation impedance detection for the rack
Check the battery rack-to-ground impedance and rectify any short circuit or inadequate insulation. Check that the PE cable is correctly connected
Rack impedance below the protection threshold on rainy and cloudy days? Change the Insulation resistance protection threshold setting

"Set Insulation resistance protection to the minimum value and restart the inverter"

Word for word from the source.

Source

Huawei Inverter Alarm Reference (EDOC1100345192), Alarm 2062 Low Insulation Resistance. Checked in Issue 10, section 32, pages 36-37. No change to this alarm up to Issue 12 (2025-10-20).support.huawei.com ↗

Where installers ask this

General guidance based on the manufacturer's manual or the named source. Always follow the current manual for your exact model and your national code. DC and AC electrical work is for qualified installers only. Not affiliated with or endorsed by any brand named; trademarks belong to their owners.