Solar Lattice

Fault codes › Enphase › Enphase IQ9N Microinverters (IQ9N-A, IQ9N-HPB)

Enphase IQ9N DC Resistance Low - Power Off

Code
DC Resistance Low - Power Off
Page
17
ID
fc:enphase-iq9n-dcresistancelowpoweroff
IRI
https://solarlattice.org/kb/fc/enphase-iq9n-dcresistancelowpoweroff
Status
active
Also known as
DC Resistance Low - Power Off, dcresistancelowpoweroff, Enphase DC Resistance Low - Power Off
Category
Inverters
Class fault verified · fact
Production stops verified · fact
Clears after a manual reset verified · fact

Decoded

Reports low insulation resistance; may indicate loss of electrical insulation; look at PV array, DC cable, DC connector.

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 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

Same code in other families

Claims

defined_in

c1 drafted · lead Enphase IQ9N Microinverter installation and operation manual

c2 drafted · lead Enphase IQ9N-HPB Microinverter installation and operation manual

reports

c3 verified · fact Low insulation resistance

PV input to ground resistance below threshold; IQ9N states 7 kOhm

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

indicates

c4 verified · fact Loss of electrical insulation

One possible cause; moisture ingress or wiring and connector defects also named

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

affects

c5 verified · fact PV array

verified by: review-workflowverified on: 2026-10-23review note: support check: partial - Passages tie the condition to PV inputs and module insulation, but they never state that it affects the PV array…

c6 verified · fact DC cable

verified by: review-workflowverified on: 2026-10-23review note: support check: partial - Defective wiring is named as a possible cause, but DC cable is not explicitly identified as an affected component.

c7 verified · fact DC connector

verified by: review-workflowverified on: 2026-10-23review note: support check: partial - Defective connectors are named as a possible cause, but the DC connector is not explicitly identified as an affected component.

has_event_class

c8 verified · fact Fault (device stops or needs intervention)

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

has_production_effect

c9 verified · fact Trip (production stops)

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

has_recovery

c10 verified · fact Manual reset (operator restarts or acknowledges)

Operator sends clear command via gateway; if condition persists, contact installer or Enphase support

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

applies_to

c11 drafted · lead Enphase IQ9N Microinverters (IQ9N-A, IQ9N-HPB)

Data