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012

Sungrow 012 on a solar inverter: excess leakage current

Verified with sources1 sourceReviewed Oct 4, 2026
Technician coming? See the 2 steps they must show you
Wall-mounted solar photovoltaic inverter
AsurnipalCC BY-SA 4.0Image source

Risk level

Medium

Proceed carefully and stop if the check is unclear.

Urgency

Medium

Quick answer

The Sungrow inverter detects excess leakage current and stops feeding in. Sungrow says it is often caused by poor sunlight or damp conditions and that it reconnects once conditions improve. If it repeats in good weather, call your installer.

Safety first

Stop and check this first

  • Leakage current means electrical risk: do not touch cables, connectors or panels, and do not climb on the roof. Checking insulation is a job for the installer only.
  • The alarm clearing when things dry out does not prove the insulation is fine: if it repeats often, ask for a measurement.

Safe checks you can perform

  • Code on the display and in iSolarCloud
  • Link with weather and time of day
  • Visual check from the ground

Leave these tasks to a qualified professional

  • Do not attempt this professional task: AC and DC cable insulation measurement
  • Do not attempt this professional task: Contact Sungrow service if it persists

What a technician must be able to justify

Technician visit

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.

  1. AC and DC cable insulation measurement

    What they doWith the system disconnected, the installer checks the AC and DC cable insulation, as Sungrow asks when conditions are normal.

    They must show youthe insulation values measured per cable or string.

    In writingwhich runs were measured, the values and which cable was repaired or replaced.

  2. Contact Sungrow service if it persists

    What they doIf conditions and insulation are correct and the fault continues, the installer opens a case with Sungrow Customer Service.

    They must show youthe fault history and the insulation measurements taken.

    In writingthe case number, Sungrow's diagnosis and whether any part was replaced.

Before accepting a part or repair

Nothing has been shown yet. Do not accept a part swap based on the code alone.

Follow these steps

Note: Follow the documented order. An error code identifies the affected system, but it does not prove by itself which part has failed.

  1. Code on the display and in iSolarCloud

    No special tools

    Who:
    you, with no tools and without opening the inverter.
    How:
    look at the LED indicator: steady red means a system fault according to Sungrow, and touching it shows the error codes on the display. In the iSolarCloud app go to Records and open Fault Alarm Record to see the detail and time of each alarm.
    Result that matters:
    confirming the code is 012 (Excess Leakage Current) and seeing how often and at what times it appears.
    If it appears once and the inverter feeds in again by itself:
    Sungrow says it normally reconnects once the grid returns to normal.
    If it repeats over several days:
    keep the history and move on to the next checks.
    Evidence to keep:
    screenshots of the Fault Alarm Record with date and time and a photo of the LED or display.

    Evidence: User Manual 1-Phase PV Grid-Connected Inverter SG2.0RS-S / SG2.5RS-S / SG3.0RS-S / SG3.0RS / SG3.6RS / SG4.0RS / SG5.0RS / SG6.0RS (SG2.0-6.0RS-UEN-Ver18-202211)

  2. Link with weather and time of day

    No special tools

    Who:
    you, comparing the history with the weather.
    How:
    note whether alarms appear with rain, fog, dew or early in the morning, and whether they clear when the day dries out or the sun comes out.
    Result that matters:
    knowing whether the fault follows the conditions, as Sungrow describes, or also appears in good weather.
    If it only appears in damp or low light and recovers by itself:
    keep an eye on it and mention it at the next service.
    If it appears in dry, sunny weather:
    ask the installer to check the cable insulation.
    Evidence to keep:
    dates, times and weather for each alarm.

    Evidence: User Manual 1-Phase PV Grid-Connected Inverter SG2.0RS-S / SG2.5RS-S / SG3.0RS-S / SG3.0RS / SG3.6RS / SG4.0RS / SG5.0RS / SG6.0RS (SG2.0-6.0RS-UEN-Ver18-202211)

  3. Visual check from the ground

    No special tools

    Who:
    you, looking from a safe spot without climbing on the roof or touching anything.
    How:
    look for cables hanging loose, chafed or with broken sheathing near the inverter or along visible runs, and whether the inverter or its connectors get direct water.
    Result that matters:
    spotting visible damage to show the installer.
    If you see a damaged cable:
    do not touch it and photograph it for the installer.
    If you see nothing abnormal:
    insulation has to be measured by the installer with proper equipment.
    Evidence to keep:
    photos of the visible cable runs and the inverter.

    Evidence: User Manual 1-Phase PV Grid-Connected Inverter SG2.0RS-S / SG2.5RS-S / SG3.0RS-S / SG3.0RS / SG3.6RS / SG4.0RS / SG5.0RS / SG6.0RS (SG2.0-6.0RS-UEN-Ver18-202211)

Still not solved

If the error persists, stop here. See what the technician must do and show you.

Where this code applies

A code is meaningful only inside the right product and version context.

Primary scope

System
Solar and energy
Brand
Sungrow
Product type
Solar inverter

Known code variants

  • Código de error 012
  • Código de error 013
  • Error 012
  • Error 013
  • Error Code 012
  • Error Code 012 (Ethernet)
  • Error Code 013
  • Sungrow 012
  • Sungrow 012 corriente de fuga
  • Sungrow 012 leakage current
  • Sungrow código 12
  • Sungrow error 012
  • Sungrow excess leakage current
  • Sungrow fallo 12
  • Sungrow fault 12
  • Sungrow fault code 12
  • Sungrow fuga a tierra
  • Sungrow leakage fault
  • TCL Roku TV error 012
  • TCL Roku TV error 012 Ethernet

What it means

Sungrow names code 12 Excess Leakage Current: the inverter measures more leakage current than allowed and disconnects. The manual explains it can be caused by poor sunlight or a damp environment, and that the inverter normally reconnects once conditions improve. If it happens in normal conditions, Sungrow asks for checks that the AC and DC cables are well insulated and, once those causes are ruled out, for Sungrow Customer Service to be contacted. The code does not say which cable or string is at fault and alone never proves that a part is faulty.

Warnings and stop conditions

  • Higheditorial warning

    Leakage current means electrical risk: do not touch cables, connectors or panels, and do not climb on the roof. Checking insulation is a job for the installer only.

    Evidence: User Manual 1-Phase PV Grid-Connected Inverter SG2.0RS-S / SG2.5RS-S / SG3.0RS-S / SG3.0RS / SG3.6RS / SG4.0RS / SG5.0RS / SG6.0RS (SG2.0-6.0RS-UEN-Ver18-202211)

  • Loweditorial warning

    The alarm clearing when things dry out does not prove the insulation is fine: if it repeats often, ask for a measurement.

    Evidence: User Manual 1-Phase PV Grid-Connected Inverter SG2.0RS-S / SG2.5RS-S / SG3.0RS-S / SG3.0RS / SG3.6RS / SG4.0RS / SG5.0RS / SG6.0RS (SG2.0-6.0RS-UEN-Ver18-202211)

Symptoms and causes

Probable causes · in order

  • Damp or poor sunlightCommon

    Sungrow points to poor sunlight or a damp environment as a usual cause; the alarm appears with dew, rain or early in the morning and clears as things dry out.

    Evidence: User Manual 1-Phase PV Grid-Connected Inverter SG2.0RS-S / SG2.5RS-S / SG3.0RS-S / SG3.0RS / SG3.6RS / SG4.0RS / SG5.0RS / SG6.0RS (SG2.0-6.0RS-UEN-Ver18-202211)

  • Damaged AC or DC cable insulationPossible

    If conditions are normal, Sungrow asks for the AC and DC cable insulation to be checked; a damaged cable lets current escape to earth.

    Evidence: User Manual 1-Phase PV Grid-Connected Inverter SG2.0RS-S / SG2.5RS-S / SG3.0RS-S / SG3.0RS / SG3.6RS / SG4.0RS / SG5.0RS / SG6.0RS (SG2.0-6.0RS-UEN-Ver18-202211)

  • Fault that persists after those checksLess common

    If conditions and insulation are fine and the fault continues, Sungrow refers you to its Customer Service to assess the unit.

    Evidence: User Manual 1-Phase PV Grid-Connected Inverter SG2.0RS-S / SG2.5RS-S / SG3.0RS-S / SG3.0RS / SG3.6RS / SG4.0RS / SG5.0RS / SG6.0RS (SG2.0-6.0RS-UEN-Ver18-202211)

Virtual technician

Does 012 still appear after these checks?

Answer a few questions to narrow down the likely cause and the safest next action. Guidance only - it never replaces a professional.

Start diagnosis

Sources and technical references

  1. 1

    User Manual 1-Phase PV Grid-Connected Inverter SG2.0RS-S / SG2.5RS-S / SG3.0RS-S / SG3.0RS / SG3.6RS / SG4.0RS / SG5.0RS / SG6.0RS (SG2.0-6.0RS-UEN-Ver18-202211)

    Sungrow Power Supply Co., Ltd. · 2022 · manual

Sources: User Manual 1-Phase PV Grid-Connected Inverter SG2.0RS-S / SG2.5RS-S / SG3.0RS-S / SG3.0RS / SG3.6RS / SG4.0RS / SG5.0RS / SG6.0RS (SG2.0-6.0RS-UEN-Ver18-202211)reviewed 2026-10-04 · verified

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