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Fault codes 004, 005: Grid Undervoltage

Applicable to SH15-20-25T series

Updated over a week ago

These faults apply to the following sungrow products:

  • SG30CX / SG33CX / SG40CX / SG50CX / SG110CX

  • SG2.0RS-S / SG2.5RS-S / SG3.0RS-S / SG3.0RS /SG3.6RS / SG4.0RS / SG5.0RS / SG6.0RS

  • SH3.0RS/SH3.6RS/SH4.0RS/SH5.0RS/SH6.0RS

  • SG3.0RT / SG4.0RT / SG5.0RT / SG6.0RT / SG7.0RT /SG8.0RT / SG10RT / SG12RT / SG15RT / SG17RT /SG20RT

  • SH5.0RT/SH6.0RT/SH8.0RT/SH10RT

  • SH5T/6T/8T/10T/12T/15T/20T/25T

  • S450S/S800S/S1600S

In the event of Fault codes 004 or 005 being informed through the App, the following corrective measures shall be taken:

Grid undervoltage (Code 004)

Fault name

Grid undervoltage (fault code: 004)

Fault type

Failure shutdown

Fault condition

The grid voltage is lower than the set protection value.

Steps and method of troubleshooting

Generally the inverter will be reconnected to the grid when the grid is back to normal.

1. Check whether the set inverter undervoltage-value and the set LVRT protection values are correct.

2. Measure the AC voltage of the AC air switch and compare the measured value with the displayed voltage and the set protection value.

If the difference between the measured voltage and the displayed voltage is large, it can be inferred that the sampling is abnormal. Please contact sungrow customer service.

Low grid voltage (Code 005)

Fault name

Low grid voltage (fault code: 005)

Fault type

Failure shutdown

Fault condition

The grid voltage is lower than the set secondary undervoltage-protection-value. (The fault is not reported if the protection level is an odd number)

Steps and method of troubleshooting

Generally the inverter will be reconnected to the grid when the grid is back to normal.

1. Check whether the set inverter undervoltage value and the set LVRT protection value are correct.

2. Measure the AC voltage of the AC air switch and compare the measured value with the displayed voltage and the set protection value.

If the difference between the measured voltage and the displayed voltage is large, it can be inferred that the sampling is abnormal. Please contact sungrow customer service.


For further information, please download the user manual here.

This manual is intended for professional technicians who are responsible for installation, operation, maintenance and troubleshooting of inverters, and users who need to check inverter parameters. The inverter must only be installed by professional technicians.

The professional technician is required to meet the following requirements:

  • Know electronic, electrical wiring and mechanical expertise, and be familiar with electrical and mechanical schematics.

  • Have received professional training related to the installation, commissioning and troubleshooting of electrical equipment.

  • Be able to quickly respond to hazards or emergencies that occur during installation, commissioning and troubleshooting.

  • Be familiar with local standards and relevant safety regulations of electrical systems.

  • Read this manual thoroughly and understand the safety instructions related to operations.

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