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2

Sungrow 2 on a solar inverter: grid overvoltage detected

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 saw grid voltage above its protection value (Grid Overvoltage) and disconnected. It normally reconnects by itself once the grid returns to normal. If it keeps happening, note the times and tell your installer.

Safety first

Stop and check this first

  • A code 2 on its own does not prove the inverter is faulty: it usually reflects grid voltage. Ask for the measurement before accepting any equipment change.
  • Do not change the overvoltage protection values yourself. Sungrow says to modify them only with the consent of the local grid operator.

Safe checks you can perform

  • Whether the inverter reconnects by itself
  • Fault record and times
  • Voltage measurement and protection settings

Leave these tasks to a qualified professional

  • Do not attempt this professional task: Actual grid voltage measurement
  • Do not attempt this professional task: Protection parameter review

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. Actual grid voltage measurement

    What they doMeasures grid voltage at the inverter connection point, ideally when the fault usually appears.

    They must show youthe measured value against the inverter's protection value.

    In writingvalues, time and whether the electricity company was informed.

  2. Protection parameter review

    What they doReviews the configured overvoltage protection values via the app or LCD.

    They must show youthe values before and after.

    In writingthe change made and the operator's approval.

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. Whether the inverter reconnects by itself

    No special tools

    Who:
    you, from the iSolarCloud app or the display.
    How:
    see whether the inverter starts producing again after the fault without you doing anything.
    Result that matters:
    whether it is a one-off disconnection or a fault that stays.
    If it reconnects by itself:
    matches what Sungrow describes when the grid returns to normal.
    If it does not reconnect or repeats often:
    pass the case to the installer.
    Evidence to keep:
    app screenshot showing the fault and the reconnection.

    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. Fault record and times

    No special tools

    Who:
    you, from the app.
    How:
    open the fault alarm record and note each occurrence of the code with date and time.
    Result that matters:
    how often it happens and at what times of day.
    If it clusters at certain times or days:
    helps the installer measure at the right moment.
    If it is isolated:
    it probably needs nothing more than monitoring.
    Evidence to keep:
    screenshots of the record with dates and times.

    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. Voltage measurement and protection settings

    Tools required

    Who:
    qualified installer or electrician.
    How:
    measure actual grid voltage at the inverter connection and review protection parameters via the app or LCD.
    Result that matters:
    measured voltage against the configured protection value.
    If voltage exceeds the value:
    Sungrow says to contact the local electricity company.
    If settings are not appropriate:
    overvoltage values are changed only with the local grid operator's consent.
    Evidence to keep:
    measured values with time and a screenshot of the parameters.

    Measuring grid voltage is work near dangerous voltage and changing protection settings needs grid operator consent. Only the installer does it.

    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

  • Sungrow 002 overvoltage
  • Sungrow 002 sobretensión de red
  • Sungrow error 002
  • Sungrow fault code 2
  • Sungrow grid overvoltage

What it means

Sungrow groups codes 2, 3, 14 and 15 as Grid Overvoltage: grid voltage exceeds the protection value set in the inverter. The manual points to the actual grid voltage, which must be measured and taken to the electricity company if it is above the value, and to the protection parameters set via the app or LCD. So the code does not point to an inverter fault: it is usually a grid or settings condition.

Warnings and stop conditions

  • Loweditorial warning

    A code 2 on its own does not prove the inverter is faulty: it usually reflects grid voltage. Ask for the measurement before accepting any equipment change.

    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)

  • Mediumsource verified

    Do not change the overvoltage protection values yourself. Sungrow says to modify them only with the consent of the local grid operator.

    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

  • Grid voltage above the set valueCommon

    Sungrow says to measure actual grid voltage and contact the electricity company if it is above the set value. Fits if it happens at certain times and clears itself.

    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)

  • Protection parameters set wronglyPossible

    The manual asks to check in the app or LCD that protection parameters are set appropriately. An unsuitable value disconnects at a voltage acceptable for the grid.

    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 2 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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