Solar PV Inverter Errors – Solis

Solis PV inverter displaying a fault code?

Sometimes a problem indicated can be resolved without the need to call anyone out or replace hardware. If not then it might give a clue as to what the root cause could be.

  • Check to see if your fault code is in the list below.
  • All fault codes shown are manufacturer supplied.
  • Follow any manufacturers advice indicated next to your error code.
  • Many inverters will show an error indicating an internal failure, this usually means a replacement is required, call us for advice or a quote.
  • If your inverter does not have a screen and is off-line you could try our home troubleshooting guide to try to get your solution working again.
  • If all else fails we would be happy to take your call on 0330 345 3400
Commercial inverter fitting service
maintenance-1
Domestic inverter fitting service without cloud connection

Repairs & Maintenance

Additional Services

These Solis fault codes are for most recent models/revisions, 4G, 5G, S6

Alarm Code or IssueBrief Explanation of AlarmBasic Troubleshooting Steps 
AFCI Check
FAULT
• AFCI module self
check fault
Reset Inverter
• DC switch OFF
• Wait until all lights/ LCD turn off
• DC switch ON
• Replace inverter
No Information – Blank Screen• DC input voltage low/missing
• DC string polarity reversed
• Internal DC short – RMA
Test – DC switch OFF
• Check string polarity to make sure it is not reversed
• Check DC string voltages >120V Single, >350V three
Test – DC Switch ON
• Check DC string voltages again >120V Single, >350V three
• If DC voltage is “0” replace inverter – internal DC short – RMA
If DC voltages are all normal but inverter won’t turn on – RMA
Initializing: Inverter stuck in this modeInverter is waiting for the
driving signal from the DSP
RMA – the inverter is not receiving a signal from the DSP board or it has a faulty internal power board
OV-G-V: Over-Grid-Voltage Alarm Inverter detects the grid
voltage as too high – has multiple iterations: V01, V02, V03, V04, and V05
Test – DC switch OFF
• Check AC at the inverter
• If AC measures high, adjust upper limit with
permission from utility
Test – DC Switch ON, full power
• Check AC at inverter test points
• Compare with LCD
• If AC measures high, cables between inverter
and interconnect are too small
• Check ampacity and voltage drop calculations
UN-G-V: Under-Grid-Voltage AlarmInverter detects the grid
voltage as too low
Test – DC switch OFF
• Check AC at the inverter test points
• If AC measures low, adjust lower limit with
permission from utility
• Check LCD voltage reading, may be a bad
measurement circuit
Test – DC Switch ON
• Check grid standard
• Replace inverter
OV-G-F: Over-Grid-Frequency AlarmInverter detects the grid
frequency as too high
Test – DC switch OFF
• Check frequency at the inverter test points
• If frequency measures high, adjust upper
limit with permission from utility
• Check LCD reading, may be a bad
measurement circuit
Test – DC Switch ON
• Check grid standard
• Replace inverter
UN-G-F: Under-Grid-Frequency Alarm

Inverter detects the grid
frequency as too low

Test – DC switch OFF
• Check frequency at the inverter test points
• If frequency measures low, adjust upper
limit with permission from utility
• Check LCD reading, may be a bad
measurement circuit
Test – DC Switch ON
• Check grid standard
• Replace inverter
NO-Grid AlarmInverter does not
detect any grid voltage
Potential Resolution: 
Turn the DC switch off and leave it off until the screen goes blank. Then turn on the AC switch followed by the DC switch. Wait to make sure the system begins generating after five minutes. If this does not work, proceed with the steps below.
Test – DC switch OFF
• Measure the AC voltage at the AC grid input terminals
• L1-L2, L1-L3, L2-L3, L1-GND, L2-GND, L3-GND
• Check the AC voltages found in the Information menu, if they do not match your multimeter – RMA (send a photo of this)
OV-DC: DC
voltage is too
high
• Inverter detects High DCVTest – DC switch OFF
• Check DC at the inverter test points
• If DCV is high, too many panels in the string
Test – DC Switch ON
• Check LCD reading, may be a bad
measurement circuit
• Replace inverter
OV-BUS: DC bus voltage is too highInverter detects high
DC voltage on the internal bus
Test
• Measure DC and AC voltages with a multimeter
• Compare with voltages found in the Information menu
• If multimeter and display voltages do not match – RMA
• If the values do match, ensure that they do not exceed the inverter specifications. If they do, reconfigure your PV strings to have lower voltage so that it is within spec
UN-BUS: DC bus voltage is too lowInverter detects low DC voltage on the internal busTest
• Measure DC and AC voltages with a multimeter
• Compare with voltages found in the Information menu
• If multimeter and display voltages do not match – RMA
• If the values do match, ensure that they do not exceed the inverter specifications. If they do, reconfigure your PV strings to have lower voltage so that it is within spec
ILeak-PRO 01/02/03/04: Current leakage to groundCurrent leakage on the AC or the DC circuitConsult the article because this one is  more complex
Fan-FailOne or more of the inverter fans is not operating

Test – DC switch ON

  • Go to Advanced Settings > Fan Test > run the test
  • Watch the fans to ensure they all spin during the test
  • If one fan is not spinning then try to spin it with your fingers – if it spins with your fingers then remove the fan and swap it with a fan that was spinning 
  • Run the test again – if the fan still does not spin after the swap, then the fan is defective and needs to be replaced 
GRID-INTF: unstable grid or faulty power boardInverter detects grid
instability, internal fault
current high
Test – With DC Switch OFF
• Measure AC voltage
• Test AC line for THD
• Test – With DC Switch ON
Test AC line for THD
• Multiple inverters/turn one off
• Impedance matching adjustment or box
• Internal damage
• Wire came loose in shipping  
DC-INTF: DC Interference FaultDC interference – faulty internal component 

Test – With DC Switch OFF

  • Measure PV string voltage positive and negative to ground – if stable voltage then locate ground-fault
  • If using MLRSD with multiple strings, then run system with one string at a time only to isolate the source of the DC fault
  • If you only have one MLRSD string, disconnect all of the receivers and run the system with full Voc – if no fault is triggered then one of the receivers is defective
  • If there is no ground-fault or defective MLRSD receiver then the fault is likely internal – contact Solis Support
G-IMPHigh grid impedanceUse the User-Define grid standard so you can adjust the protection limit if it is allowed by the utility
INI-FAULT:
Initialization
Protection    
• Master and Slave DSP
have different values
Reset Inverter
• DC switch OFF
• Wait until all lights/LCD turn off
• DC switch ON
• Replace inverter
OV-TEM:
Temperature
Protection
• Inverter detects high
ambient temperature >60C
Inspect installation
• Check heatsink for obstructions/ventilation
• Is inverter in direct sunshine
• Measure ambient temperature near inverter
• If temp is in range replace inverter
PV ISO-PRO 01/02: Ground-fault detected on the DC sideInverter detects low DC
insulation resistance – ground fault on one of the PV strings
Inspect installation
• Reset inverter
• Note weather conditions when alarm occurs
• Measure insulation resistance
• If normal, measure in SAME weather as alarm
• Physically check cables
• Replace inverter
ARC-Fault: An arc fault has been detectedInverter detects an arc
in the DC circuit
Inspect installation
• Physically check cables
• Inspect panel junction boxes
• Inspect cable connections
• Reset inverter
• Replace inverter
IG-AD: Grid current sampling failure

Internal component failure

Fault caused by internal component failure – RMA
LimByVg: Power curtailed due to grid voltagePower is being curtailed because of the grid voltage being too high or too low • Inspect panel junction boxes
• Inspect cable connections
• Reset inverter
• Replace inverter
LimbyTemp    Temp Below 17C.  Inv Could limit power to 50%    1. Wait until internal temperature rises above 17C
Relay-FaultRelay check faultRestart inverter or contact installer.
DCinj-FaultHigh DC injection currentRestart inverter or contact installer.
Stuck in Soft Run Mode RMA
IGFOL-FGrid Current Tracking ErrorRestart the inverter – if the alarm persists, RMA

 

For the RHI-1P(5-10)K-HVES-5G series

Alarm Code or Issue

Failure Description

Solution

AC
Overcurrent

High current demand from the backup loads or a faulty outlet

There is too much draw on the backup loads panel > 25A reduce the
current draw or install a 25A supply breaker so there is an OCPD in place –
check to make sure no outlets are tripping

AC Transient over current

AC Transient Overcurrent

Check if the backup port is shorted, restart the inverter

LmtByPLmt

Output power reduced due to Export Power configuration

Output power is being limited because the system is currently set up
for minimum export. Please see Export
Power Set
 on how to change this if you want the system to be
exporting power. 

LimByVg

Limited by grid voltage

If Rule 21 is unnecessary, then set working mode to “NULL”
but if Rule 21 is required, know that this code is designed to protect the
inverter and is normal but if the code is given for long periods of time then
it could mean there is an issue with the inverter or grid. 

IGBT-OV-I

IGBT Overcurrent

Restart the inverter

OV-IgTr

Grid Transient Overcurrent

Restart the inverter

OV-Vbatt-H

Battery Hardware Overcurrent

Check if the battery is correctly connected or the battery contactor
is disconnected, restart the battery, restart the inverter

OV-ILLC

LLC Hardware Overcurrent

Restart the inverter

OV-Vbatt

Battery Overvoltage

Check if the battery overvoltage setting is reasonable, if the battery
reaches its end of life

UN-Vbatt

Battery Undervoltage

Check if the battery undervoltage setting is reasonable, if the
battery reaches its end of life

DSP-B-FAULT

Slave DSP Check Error

Restart the inverter

NO-Battery

Battery Not Connected

Check if the battery is correctly connected or the battery contactor
is disconnected, Restart the battery

OV-Vbackup

Inverting Overvoltage

Restart the inverter

Over-Load

Backup Overload

Check if the backup port is shorted or the load is larger than the
limitation

FailSafe

Inverter and meter communication failure -FailSafe is enabled

Troubleshoot communication between the inverter and meter. See the
article FailSafe on
how to disable this setting if you do not want it enabled.

MET_Comm-FAIL

Inverter and external (Acrel) meter are not communicating

Make sure the RS485 between the inverter and meter is installed
properly. If no meter is installed, change to “No Meter”

CAN_Comm_FAIL

Battery CAN Fail

Check if the CAN cable is correctly connected or the cables are
broken/loosen

DSP_Comm_FAIL

DSP COM Fail

Restart the inverter

Alarm-BMS

Battery BMS Alarm

Retart the battery, if fault still exists, please contact battery
manufacturer or installer 

BAT_Comm-FAIL

No communication between the inverter and battery OR the wrong battery
is selected

Check the RS485 or CAN wire between the inverter and battery. Verify
that the correct battery has been selected in the Battery Select submenu of
Advanced Settings

LG-DDC-OV

LG Battery overvoltage 

Turn both battery breaker off and then back on again after ten
minutes. 

LG-Comm-FAIL

LG Battery Com Fail

Check the RS485 cable of LG battery. Ensure it is correctly connected
without broken insulation

LG-BMS-Fault

LG BMS is having it’s own fault and the inverter is just relaying the
message

Restart the battery. If the fault still exists, contact LG for assistance

Alarm Code or Issue

Failure Description

Solution

AC Overcurrent

High current demand from the backup loads or a faulty outlet

There is too much draw on the backup loads panel > 25A reduce the
current draw or install a 25A supply breaker so there is an OCPD in place –
check to make sure no outlets are tripping

AC Transient over current

AC Transient Overcurrent

Check if the backup port is shorted, restart the inverter

LmtByPLmt

Output power reduced due to Export Power configuration

Output power is being limited because the system is currently set up
for minimum export. Please see Export Power Set on how to change this
if you want the system to be exporting power. 

LimByVg

Limited by grid voltage

If Rule 21 is unnecessary, then set working mode to “NULL”
but if Rule 21 is required, know that this code is designed to protect the
inverter and is normal but if the code is given for long periods of time then
it could mean there is an issue with the inverter or grid. 

IGBT-OV-I

IGBT Overcurrent

Restart the inverter

 

OV-IgTr

Grid Transient Overcurrent

Restart the inverter

OV-Vbatt-H

Battery Hardware Overcurrent

Check if the battery is correctly connected or the battery contactor
is disconnected, restart the battery, restart the inverter

OV-ILLC

LLC Hardware Overcurrent

Restart the inverter

OV-Vbatt

Battery Overvoltage

Check if the battery overvoltage setting is reasonable, if the battery
reaches its end of life

UN-Vbatt

Battery Undervoltage

Check if the battery undervoltage setting is reasonable, if the
battery reaches its end of life

DSP-B-FAULT

Slave DSP Check Error

Restart the inverter

NO-Battery

Battery Not Connected

Check if the battery is correctly connected or the battery contactor is
disconnected, Restart the battery

OV-Vbackup

Inverting Overvoltage

Restart the inverter

Over-Load

Backup Overload

Check if the backup port is shorted or the load is larger than the
limitation

FailSafe

Inverter and meter communication failure -FailSafe is enabled

Troubleshoot communication between the inverter and meter. See the
article FailSafe on how to disable this setting
if you do not want it enabled.

MET_Comm-FAIL

Inverter and external (Acrel) meter are not communicating

Make sure the RS485 between the inverter and meter is installed
properly. If no meter is installed, change to “No Meter”

CAN_Comm_FAIL

Battery CAN Fail

Check if the CAN cable is correctly connected or the cables are
broken/loosen

DSP_Comm_FAIL

DSP COM Fail

Restart the inverter

Alarm-BMS

Battery BMS Alarm

Retart the battery, if fault still exists, please contact battery
manufacturer or installer 

BAT_Comm-FAIL

No communication between the inverter and battery OR the wrong battery
is selected

Check the RS485 or CAN wire between the inverter and battery. Verify
that the correct battery has been selected in the Battery Select submenu of
Advanced Settings

LG-DDC-OV

LG Battery overvoltage 

Turn both battery breaker off and then back on again after ten
minutes. 

LG-Comm-FAIL

LG Battery Com Fail

Check the RS485 cable of LG battery. Ensure it is correctly connected
without broken insulation

LG-BMS-Fault

LG BMS is having it’s own fault and the inverter is just relaying the
message

Restart the battery. If the fault still exists, contact LG for assistance

Alarm Code or Issue

Failure Description

Solution

AC
Overcurrent

High current demand from the backup loads or a faulty outlet

There is too much draw on the backup loads panel > 25A reduce the
current draw or install a 25A supply breaker so there is an OCPD in place –
check to make sure no outlets are tripping

AC Transient over current

AC Transient Overcurrent

Check if the backup port is shorted, restart the inverter

LmtByPLmt

Output power reduced due to Export Power configuration

Output power is being limited because the system is currently set up
for minimum export. Please see Export
Power Set
 on how to change this if you want the system to be
exporting power. 

LimByVg

Limited by grid voltage

If Rule 21 is unnecessary, then set working mode to “NULL”
but if Rule 21 is required, know that this code is designed to protect the
inverter and is normal but if the code is given for long periods of time then
it could mean there is an issue with the inverter or grid. 

IGBT-OV-I

IGBT Overcurrent

Restart the inverter

OV-IgTr

Grid Transient Overcurrent

Restart the inverter

OV-Vbatt-H

Battery Hardware Overcurrent

Check if the battery is correctly connected or the battery contactor
is disconnected, restart the battery, restart the inverter

OV-ILLC

LLC Hardware Overcurrent

Restart the inverter

OV-Vbatt

Battery Overvoltage

Check if the battery overvoltage setting is reasonable, if the battery
reaches its end of life

UN-Vbatt

Battery Undervoltage

Check if the battery undervoltage setting is reasonable, if the
battery reaches its end of life

DSP-B-FAULT

Slave DSP Check Error

Restart the inverter

NO-Battery

Battery Not Connected

Check if the battery is correctly connected or the battery contactor
is disconnected, Restart the battery

OV-Vbackup

Inverting Overvoltage

Restart the inverter

Over-Load

Backup Overload

Check if the backup port is shorted or the load is larger than the
limitation

FailSafe

Inverter and meter communication failure -FailSafe is enabled

Troubleshoot communication between the inverter and meter. See the
article FailSafe on
how to disable this setting if you do not want it enabled.

MET_Comm-FAIL

Inverter and external (Acrel) meter are not communicating

Make sure the RS485 between the inverter and meter is installed
properly. If no meter is installed, change to “No Meter”

CAN_Comm_FAIL

Battery CAN Fail

Check if the CAN cable is correctly connected or the cables are
broken/loosen

DSP_Comm_FAIL

DSP COM Fail

Restart the inverter

Alarm-BMS

Battery BMS Alarm

Retart the battery, if fault still exists, please contact battery
manufacturer or installer 

BAT_Comm-FAIL

No communication between the inverter and battery OR the wrong battery
is selected

Check the RS485 or CAN wire between the inverter and battery. Verify
that the correct battery has been selected in the Battery Select submenu of
Advanced Settings

LG-DDC-OV

LG Battery overvoltage 

Turn both battery breaker off and then back on again after ten
minutes. 

LG-Comm-FAIL

LG Battery Com Fail

Check the RS485 cable of LG battery. Ensure it is correctly connected
without broken insulation

LG-BMS-Fault

LG BMS is having it’s own fault and the inverter is just relaying the
message

Restart the battery. If the fault still exists, contact LG for assistance

Alarm Code or Issue

Failure Description

Solution

AC Overcurrent

High current demand from the backup loads or a faulty outlet

There is too much draw on the backup loads panel > 25A reduce the
current draw or install a 25A supply breaker so there is an OCPD in place –
check to make sure no outlets are tripping

AC Transient over current

AC Transient Overcurrent

Check if the backup port is shorted, restart the inverter

LmtByPLmt

Output power reduced due to Export Power configuration

Output power is being limited because the system is currently set up
for minimum export. Please see Export Power Set on how to change this
if you want the system to be exporting power. 

LimByVg

Limited by grid voltage

If Rule 21 is unnecessary, then set working mode to “NULL”
but if Rule 21 is required, know that this code is designed to protect the
inverter and is normal but if the code is given for long periods of time then
it could mean there is an issue with the inverter or grid. 

IGBT-OV-I

IGBT Overcurrent

Restart the inverter

 

OV-IgTr

Grid Transient Overcurrent

Restart the inverter

OV-Vbatt-H

Battery Hardware Overcurrent

Check if the battery is correctly connected or the battery contactor
is disconnected, restart the battery, restart the inverter

OV-ILLC

LLC Hardware Overcurrent

Restart the inverter

OV-Vbatt

Battery Overvoltage

Check if the battery overvoltage setting is reasonable, if the battery
reaches its end of life

UN-Vbatt

Battery Undervoltage

Check if the battery undervoltage setting is reasonable, if the
battery reaches its end of life

DSP-B-FAULT

Slave DSP Check Error

Restart the inverter

NO-Battery

Battery Not Connected

Check if the battery is correctly connected or the battery contactor is
disconnected, Restart the battery

OV-Vbackup

Inverting Overvoltage

Restart the inverter

Over-Load

Backup Overload

Check if the backup port is shorted or the load is larger than the
limitation

FailSafe

Inverter and meter communication failure -FailSafe is enabled

Troubleshoot communication between the inverter and meter. See the
article FailSafe on how to disable this setting
if you do not want it enabled.

MET_Comm-FAIL

Inverter and external (Acrel) meter are not communicating

Make sure the RS485 between the inverter and meter is installed
properly. If no meter is installed, change to “No Meter”

CAN_Comm_FAIL

Battery CAN Fail

Check if the CAN cable is correctly connected or the cables are
broken/loosen

DSP_Comm_FAIL

DSP COM Fail

Restart the inverter

Alarm-BMS

Battery BMS Alarm

Retart the battery, if fault still exists, please contact battery
manufacturer or installer 

BAT_Comm-FAIL

No communication between the inverter and battery OR the wrong battery
is selected

Check the RS485 or CAN wire between the inverter and battery. Verify
that the correct battery has been selected in the Battery Select submenu of
Advanced Settings

LG-DDC-OV

LG Battery overvoltage 

Turn both battery breaker off and then back on again after ten
minutes. 

LG-Comm-FAIL

LG Battery Com Fail

Check the RS485 cable of LG battery. Ensure it is correctly connected
without broken insulation

LG-BMS-Fault

LG BMS is having it’s own fault and the inverter is just relaying the
message

Restart the battery. If the fault still exists, contact LG for assistance

Remember, our engineering staff are never more than an hour away and can have you back up and running in no time

Give us a call, we will take your details, arrange an engineer, and aim to resolve your solar problem as soon as possible.

Photos are always an effective way to show us your problem too.

 

Call Bolido Solar on 0330 345 3400 or use the inquiry form and we will call you back

Tim Foreman
Tim Foreman
4 weeks ago
Read More
Scott designed and carried out a PV cell installation recently. The quote was competitive and the correspondence quick and concise. The fitting was arranged within a week, once the specification was agreed. On site, assisted by Mike, they were helpful and friendly and despite a difficult routing for the cable they came up with a successful solution. The end result is a very tidy, externally & internally, solar fit for the property. Great job and communication throughout, overall I'm very satisfied with their service and would recommend them.
Elspeth Robinson
Elspeth Robinson
3 weeks ago
Read More
Thank you for your outstanding service we received with regards to our solar panels which needed a new inverter. In next to no time, the problem was identified, a replacement ordered, delivered and fitted and the solar panels immediately started to record our readings. I have 100% confidence in recommending Bolido!
Greg Bertrum
Greg Bertrum
2 weeks ago
Read More
Very refreshing to get such a thorough and decent service. My company, a solar installations company needed technical assistance on-site for two projects. We also needed help with some of our own IT systems particularly with providing secure internet and network access between us and our clients, primarily for sharing power generation data but also increasingly alongside power usage data. Scott and his team were great with our clients and we just left to it. They were also quick to understand exactly what we wanted to achieve. They carried out all of the work, quickly, cleanly and with the minimum of fuss. We are now in a great position network and IT wise, moving forward we are confident in being able to service bigger clients with however sophisticated a network solution they might require. Highly recommend this company.
Little Miss Psycho
Little Miss Psycho
1 week ago
Read More
Fantastic and thorough service from these guys following birds nesting and ruining the connections on our solar installation. Great communications throughout, and friendly professional service.