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Fault codes › Solis › Solis S6-GC(25-60)K-US

Solis S6-GC UN-BUS

Code
UN-BUS
Shown as
DC BUS voltage is too low
Page
70
ID
fc:solis-s6-gc-us-unbus
IRI
https://solarlattice.org/kb/fc/solis-s6-gc-us-unbus
Status
active
Also known as
UN-BUS, unbus, Solis UN-BUS, DC BUS voltage is too low
Category
Inverters
Class fault drafted · lead
Production not stated
Clears not stated

Decoded

Reports DC bus undervoltage; look at inverter; confirm with DC voltage measurement; do: inverter restart, inverter replacement.

What can be behind DC bus undervoltage

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 E010, ABB / FIMER PVS-166-175-TL W011, ABB / FIMER PVS-60-TL E010, ABB / FIMER PVS-60-TL W011, ABB / FIMER TRIO-20.0-27.6-TL E010, ABB / FIMER TRIO-20.0-27.6-TL W011, ABB / FIMER UNO-DM-3.3-5.0-PLUS E010, ABB / FIMER UNO-DM-3.3-5.0-PLUS W011, ABB / FIMER UNO-DM-6.0-PLUS E010, ABB / FIMER UNO-DM-6.0-PLUS W011
CPS
CPS SCA50-100K-T Fault6080
Canadian Solar
Canadian Solar 125K-T600GL02 UN-BUS, Canadian Solar 125KTL-GS-E UN-BUS, Canadian Solar 185-255K UN-BUS01/02, Canadian Solar 25-40K-T480GL01 UN-BUS, Canadian Solar 25-40KTL-GS-FL UN-BUS, Canadian Solar 50-66K-T480GL01 UN-BUS, Canadian Solar 50-66KTL-GS-FL UN-BUS, Canadian Solar 75-100K-T480GL02 UN-BUS
Fronius
Fronius Primo 443, Fronius Symo 443
KACO new energy
KACO new energy blueplanet TL3 84
Solis
Solis 1P-4G-US UN-BUS, Solis 3P-5G-US UN-BUS01/02, Solis RHI-1P-HV UN-BUS01/02, Solis S5-GC UN-BUS, Solis S6-EH1P UN-BUS01/02, Solis S6-EH2P UN-BUS01, Solis S6-EH3P30-60K UN-BUS01, Solis S6-EH3P75-150K UN-BUS01, Solis S6-GU UN-BUS

Same code in other families

Claims

defined_in

c1 drafted · lead Solis_Manual_S6_GC(25-60)K-US_V1.1(20251013)

c2 drafted · lead Solis S6-GC30K-LV-US Manual V1.2

reports

c3 drafted · lead DC bus undervoltage

detected_by

c4 verified · fact DC voltage measurement

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

affects

c5 drafted · lead Inverter

Internal damage or wire loosened in shipping.

mitigated_by

c6 drafted · lead Inverter restart

c7 drafted · lead Inverter replacement

has_event_class

c8 drafted · lead Fault (device stops or needs intervention)

review note: support check: partial - Row says 'DC bus voltage too low for inverter to operate' and suggests restart or replace, implying a stop, but…

applies_to

c9 drafted · lead Solis S6-GC(25-60)K-US

Data