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Fault codes › Sungrow › Sungrow SG250HX

Sungrow SG250HX 39

Code
39
Shown as
Low System Insu-lation Resistance
Page
94
ID
fc:sungrow-sg250hx-39
IRI
https://solarlattice.org/kb/fc/sungrow-sg250hx-39
Status
active
Also known as
39, Sungrow 39, Low System Insu-lation Resistance
Category
Inverters
Class not stated
Production not stated
Clears by itself drafted · lead

Decoded

Reports low insulation resistance; may indicate loss of electrical insulation; look at DC cable; confirm with insulation resistance testing, inverter settings review; do: DC wiring check.

What can be behind Low insulation resistance

Failure modes that present as the reported condition, and the tests that tell them apart.

Defined in

The manufacturer's own cause and corrective text is not reproduced here.

Same condition on other equipment

ABB / FIMER
ABB / FIMER PVS-166-175-TL E025, ABB / FIMER PVS-166-175-TL E037, ABB / FIMER PVS-60-TL E025, ABB / FIMER PVS-60-TL E037, ABB / FIMER TRIO-20.0-27.6-TL E025, ABB / FIMER TRIO-20.0-27.6-TL E037, ABB / FIMER UNO-DM-3.3-5.0-PLUS E025, ABB / FIMER UNO-DM-6.0-PLUS E025
CPS
CPS SCA25KTL-208 IsolationErr, CPS SCA25KTL-480 IsolationErr, CPS SCA36KTL IsolationErr, CPS SCA50-100K-T Protect0190, CPS SCA50-60KTL IsolationErr, CPS SCH100-125KTL IsolationErr, CPS SCH125KTL-AIO IsolationErr, CPS SCH200-250K-T IsolationErr, CPS SCH275KTL IsolationErr, CPS SCH350KTL IsolationErr
Canadian Solar
Canadian Solar 125K-T600GL02 PV ISO-PRO 01/02, Canadian Solar 125K-T600GL02 PV-MID-ISO, Canadian Solar 185-255K PV ISO-PRO 01/02, Canadian Solar 23-28KTL-CT IsolationErr, Canadian Solar 25-40K-T480GL01 PV ISO-PRO 01/02, Canadian Solar 50-66K-T480GL01 PV ISO-PRO 01/02, Canadian Solar 75-100K-T480GL02 PV ISO-PRO 01/02
Enphase
Enphase IQ7 DC Resistance Low - Power Off, Enphase IQ8 DC Resistance Low - Power Off, Enphase IQ9N DC Resistance Low - Power Off, Enphase M215-M250 DC Resistance Low - Power Off
Fronius
Fronius Galvo 502, Fronius Primo 447, Fronius Primo 502, Fronius Symo 447, Fronius Symo 502
Huawei
Huawei SUN2000-100KTL-USH0 2062, Huawei SUN2000-25-30KTL-US 313, Huawei SUN2000-45KTL-US-HV-D0 313
KACO new energy
KACO new energy blueplanet TL3 181, KACO new energy blueplanet TL3 182, KACO new energy blueplanet TL3 183
SMA
SMA SB-US-40 3501, SMA SB-US-41 3501, SMA SBSE-US-50 3501, SMA PEAK3-US 3501, SMA CORE1-US 3501, SMA STP-TL-US 3501, SMA STP-X-US 3501, SMA SC-CP-XT 3501, SMA SC-CP-XT 3504, SMA SC-CP-XT 3510, SMA SC-CP-XT 3511
Schneider Electric
Schneider Electric CL125 039, Schneider Electric CL125 055
Solis
Solis 1P-4G-US PV ISO-PRO 01/02, Solis 3P-5G-US PV ISO-PRO 01/02, Solis RHI-1P-HV PV ISO-PRO 01/02, Solis S5-GC PV ISO-PRO 01/02, Solis S6-EH1P PV ISO-PRO 01/02, Solis S6-GC PV ISO-PRO 01/02, Solis S6-GU PV ISO-PRO 01/02
Sungrow
Sungrow SG-CX-US 039, Sungrow SG200HX 039, Sungrow SG350HX 039
Yaskawa Solectria
Yaskawa Solectria PVI-25TL-R IsolationErr, Yaskawa Solectria PVI-TL IsolationErr

Same code in other families

Claims

defined_in

c1 drafted · lead SG250HX-US-UEN-Ver17-202203

reports

c2 drafted · lead Low insulation resistance

indicates

c3 drafted · lead Loss of electrical insulation

detected_by

c4 verified · fact Insulation resistance testing

verified by: review-workflowverified on: 2026-10-20review note: support check: partial - Passages say to check resistance to ground of string/DC cable, but don't state the fault is detected by insulation resistance…

c5 drafted · lead Inverter settings review

review note: support check: partial - Passages say to check the ISO protection value setting, a troubleshooting step rather than a detection method; roughly implied.

affects

c6 drafted · lead DC cable

mitigated_by

c7 verified · fact DC wiring check

verified by: review-workflowverified on: 2026-10-20

has_recovery

c8 drafted · lead Auto-reset (clears by itself)

Normally clears itself; repeated occurrence leads to settings and insulation checks, then service.

applies_to

c9 drafted · lead Sungrow SG250HX-US

Data