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Fault codes › Canadian Solar › CSI 23/28KTL-CT/US-480

Canadian Solar 23-28KTL-CT IsolationErr

Code
IsolationErr
Vendor severity
Protection
Page
73
ID
fc:canadian-solar-23-28ktl-ct-isolationerr
IRI
https://solarlattice.org/kb/fc/canadian-solar-23-28ktl-ct-isolationerr
Status
active
Also known as
IsolationErr, isolationerr, Canadian Solar IsolationErr
Category
Inverters
Class fault drafted · lead
Production stops drafted · lead
Clears by itself drafted · lead

Decoded

Reports low insulation resistance; look at PV array; confirm with insulation resistance testing.

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 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 SG250HX 39, Sungrow SG350HX 039
Yaskawa Solectria
Yaskawa Solectria PVI-25TL-R IsolationErr, Yaskawa Solectria PVI-TL IsolationErr

Claims

defined_in

c1 drafted · lead CSI 23-28KTL-CT Inverter Installation Manual

has_event_class

c2 drafted · lead Fault (device stops or needs intervention)

from the Type column

reports

c3 verified · fact Low insulation resistance

verified by: review-workflowverified on: 2026-10-23

affects

c4 drafted · lead PV array

detected_by

c5 drafted · lead Insulation resistance testing

review note: support check: partial - The row concerns insulation impedance and says to check PV system insulation, but does not name insulation resistance testing as…

has_production_effect

c6 drafted · lead Trip (production stops)

review note: support check: partial - The general text says the inverter shuts down on faults, but the row does not state production stops.

has_recovery

c7 drafted · lead Auto-reset (clears by itself)

May clear by itself within 10 minutes, e.g. humidity related; then insulation check, then service.

applies_to

c8 drafted · lead CSI 23/28KTL-CT/US-480

Data