Solar Lattice

Fault codes › SMA › Sunny Boy 3.0-7.7-US (SBx.x-1SP/1TP-US-40)

SMA SB-US-40 3501

Code: 3501
Shown as: Insulation failure > Check generator
Page: 49
ID: fc:sma-sb-us-40-3501
IRI: https://solarlattice.org/kb/fc/sma-sb-us-40-3501
Status: active
Also known as: 3501, SMA 3501, Insulation failure > Check generator
Category: Inverters

Class fault verified · fact

Production stops drafted · lead

Clears not stated

Decoded

Reports ground fault alarm or trip, low insulation resistance; may indicate loss of electrical insulation; look at PV array, DC cable, DC connector; confirm with insulation resistance testing, open-circuit voltage measurement, DC voltage measurement, visual inspection, infrared thermography; do: DC wiring check.

What can be behind Ground fault alarm or trip

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

Backsheet Cracking drafted · lead
Cable Defect verified · fact
Connector Defect drafted · lead
Glass Breakage drafted · lead
Grounding fuse failure verified · fact
Loss of electrical insulation drafted · lead

What can be behind Low insulation resistance

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

Defined in

SBxx-US-1XP-40-BA-en-13 — SMA · page 49 drafted · lead
- sec=h203 h=92ad3965bba5
- sec=h204 h=90a2ed93d28f

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 E018, ABB / FIMER PVS-166-175-TL E025, ABB / FIMER PVS-166-175-TL E037, ABB / FIMER PVS-60-TL E018, ABB / FIMER PVS-60-TL E025, ABB / FIMER PVS-60-TL E037, ABB / FIMER TRIO-20.0-27.6-TL E018, 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 E018, ABB / FIMER UNO-DM-3.3-5.0-PLUS E025, ABB / FIMER UNO-DM-6.0-PLUS E018, ABB / FIMER UNO-DM-6.0-PLUS E025
CPS: CPS SCA25KTL-208 IsolationErr, CPS SCA25KTL-480 IsolationErr, CPS SCA36KTL IsolationErr, CPS SCA50-100K-T PFault0040, CPS SCA50-100K-T Protect0190, CPS SCA50-100K-T Protect0200, 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, Enphase M215-M250 GFI Tripped
Fronius: Fronius Galvo 475, Fronius Galvo 502, Fronius Primo 447, Fronius Primo 475, Fronius Primo 502, Fronius Symo 447, Fronius Symo 475, Fronius Symo 502
Huawei: Huawei SUN2000-100KTL-USH0 2031, 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 3601, SMA SB-US-40 3701, SMA SB-US-41 3501, SMA SB-US-41 3601, SMA SB-US-41 3701, SMA SBSE-US-50 3501, SMA SBSE-US-50 3601, SMA SBSE-US-50 3701, SMA PEAK3-US 3501, SMA PEAK3-US 3601, SMA PEAK3-US 3701, SMA CORE1-US 3501, SMA CORE1-US 3701, SMA STP-TL-US 3501, SMA STP-TL-US 3601, SMA STP-TL-US 3701, SMA STP-X-US 3501, SMA STP-X-US 3601, SMA STP-X-US 3701, SMA SC-CP-XT 3501, SMA SC-CP-XT 3502, SMA SC-CP-XT 3504, SMA SC-CP-XT 3507, SMA SC-CP-XT 3510, SMA SC-CP-XT 3511, SMA SC-CP-XT 3512, SMA SC-CP-XT 3515, SMA SC-CP-XT 3601, SMA SC-CP-XT 6487
Schneider Electric: Schneider Electric CL125 033, 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-EH2P PV ISO-PRO01, Solis S6-EH2P PV ISO-PRO02, Solis S6-EH3P30-60K PV ISO-PRO01, Solis S6-EH3P30-60K PV ISO-PRO02, Solis S6-EH3P75-150K PV ISO-PRO01, Solis S6-EH3P75-150K PV ISO-PRO02, Solis S6-GC PV ISO-PRO 01/02, Solis S6-GU PV ISO-PRO 01/02
Sungrow: Sungrow SG-CX-US 039, Sungrow SG200HX 1600-1615, Sungrow SG200HX 1632-1655, Sungrow SG200HX 039, Sungrow SG250HX 1600-1615, Sungrow SG250HX 1632-1655, Sungrow SG250HX 39, Sungrow SG350HX 1600-1615, Sungrow SG350HX 1632-1655, Sungrow SG350HX 039
Yaskawa Solectria: Yaskawa Solectria PVI-25TL-R IsolationErr, Yaskawa Solectria PVI-TL IsolationErr, Yaskawa Solectria SGI-XTM DC GND Fault, Yaskawa Solectria SGI-XTM RCM Fault, Yaskawa Solectria XGI-1500-1MW CRIT-7, Yaskawa Solectria XGI-1500 CRIT-7, Yaskawa Solectria XGI-1500-DCG CRIT-7

Same code in other families

Claims

`defined_in`

c1 drafted · lead SBxx-US-1XP-40-BA-en-13

SBxx-US-1XP-40-BA-en-13 sec=h203 h=92ad3965bba5
SBxx-US-1XP-40-BA-en-13 sec=h204 h=90a2ed93d28f

`reports`

c2 drafted · lead Ground fault alarm or trip

SBxx-US-1XP-40-BA-en-13 sec=h204 h=90a2ed93d28f
STPTL-US-10-IA-xx-22 tbl=15.r3 h=37b0c92512b9
SBxx-US-1XP-41-BA-en-12 sec=h277 h=aa84d8588c73
SBSExx-US-50-BE-en-11 sec=h559 h=b4a70384c4fe
SHPxxx-US-21-BE-en-11 sec=h320 h=aa84d8588c73

c3 drafted · lead Low insulation resistance

SCCPXT-E7-WA-en-37 tbl=35.r1 h=82dbfd767650
STPxx-US-50-BE-en-14 sec=h453 h=ff98adfd21c5

`indicates`

c4 drafted · lead Loss of electrical insulation

Defective insulation or faulty plug connections are named as the frequent cause.

STPxx-US-50-BE-en-14 sec=h453 h=ff98adfd21c5

`affects`

c5 drafted · lead PV array

SBxx-US-1XP-40-BA-en-13 sec=h204 h=90a2ed93d28f
STPTL-US-10-IA-xx-22 tbl=15.r3 h=37b0c92512b9
SCCPXT-E7-WA-en-37 tbl=35.r1 h=82dbfd767650

c6 drafted · lead DC cable

SBSExx-US-50-BE-en-11 sec=h560 h=8ca40d7d772c
STPxx-US-50-BE-en-14 sec=h453 h=ff98adfd21c5

c7 drafted · lead DC connector

STPxx-US-50-BE-en-14 sec=h453 h=ff98adfd21c5
STPxx-US-50-BE-en-14 sec=h454 h=736fbc74e526

`detected_by`

c8 drafted · lead Insulation resistance testing

STPxx-US-50-BE-en-14 sec=h454 h=736fbc74e526

c9 drafted · lead Open-circuit voltage measurement

STPxx-US-50-BE-en-14 sec=h454 h=736fbc74e526

review note: support check: partial - Open-circuit voltage measurement is listed as a verification step, but not explicitly as detection of this fault.

c10 drafted · lead DC voltage measurement

String pole-to-ground voltage measurement.

STPxx-US-50-BE-en-14 sec=h454 h=736fbc74e526

c11 drafted · lead Visual inspection

SBSExx-US-50-BE-en-11 sec=h560 h=8ca40d7d772c
STPxx-US-50-BE-en-14 sec=h454 h=736fbc74e526

c12 drafted · lead Infrared thermography

STPxx-US-50-BE-en-14 sec=h454 h=736fbc74e526

review note: support check: partial - IR camera is only a tip for support, not a stated detection method.

`mitigated_by`

c13 drafted · lead DC wiring check

STP33-62-US-41-BA-en-13 sec=h262 h=e4a2a2e70403
STP33-62-US-41 ops manual sec=h179 h=e4a2a2e70403
SBxx-US-1XP-40-BA-en-13 sec=h205 h=7f7d30d371d5
SBxx-US-1XP-41-BA-en-12 sec=h278 h=3450f514b95f
SBSExx-US-50-BE-en-11 sec=h560 h=8ca40d7d772c
SHPxxx-US-21-BE-en-11 sec=h321 h=3450f514b95f

`has_event_class`

c14 verified · fact Fault (device stops or needs intervention)

STPxx-US-50-BE-en-14 sec=h453 h=ff98adfd21c5
Event 3501 with Sunny Boy Smart Energy SBSE-US-50 sec=h1 h=05d7bba15124

verified by: review-workflowverified on: 2026-10-23review note: support check: partial - Inverter disconnects/does not operate, but 'Fault' classification isn't explicitly stated.

`has_production_effect`

c15 drafted · lead Trip (production stops)

Inverter disconnects from grid or fails to connect during self-test.

STPxx-US-50-BE-en-14 sec=h453 h=ff98adfd21c5
Event 3501 with Sunny Boy Smart Energy SBSE-US-50 sec=h1 h=05d7bba15124

`applies_to`

c16 drafted · lead Sunny Boy 3.0-7.7-US-40 proposed

SBxx-US-1XP-40-BA-en-13 sec=h203 h=92ad3965bba5
SBxx-US-1XP-40-BA-en-13 sec=h204 h=90a2ed93d28f

Data