EcoNet and Flash Codes Inverter Product

The error codes below will be displayed at the EcoNet Control Center under Service window / Current Faults or in the Fault History and will be time & date stamped. VSODU (Variable Speed Outdoor Unit Control – EcoNet control board) fault code is what will be displayed on the VSODU

EcoNet error code at Control VSODU Description Possible Resolution(s) EV2 Drive LED Code Center Fault Code  The inverter drive itself is not programmed and is not field A900_O Inverter Fault – LED’s unlikely to display serviceable.  Replace drive. Identity Fault  anything   This fault should not occur in the field.  Compressor Shorted to Ground – Check resistance of windings to Yellow 1 or 3 Flashes ground.

 Wiring to compressor or molded plug T901_O Inverter Fault –  Compressor is pulling more Or damaged – Inspect compressor wiring Compressor Overcurrent current than allowed  harness. Red 4 Flashes  Wire not secure on U, V, or W – Check

connections.  Defective Drive – Replace Drive  Will display 31 at VSODU at time of fault – Will return to operation after time delay  Compressor current outside of T902 Inverter Fault –  Must occur 15 times in a 24 hour predetermined envelope for Envelope Protection period to be displayed in control  RPM’s center fault history  Verify refrigerant charge, often related to overcharge  PFC (Power Factor Correction) T903_O Inverter Fault – module is detecting high current  Replace Drive PFC Overcurrent  internally

EcoNet and Flash Codes Inverter Product

 Verify line voltage to equipment/drive does not exceed T904_O Inverter Fault –  Correct incoming line voltage issue maximum allowable voltages Yellow 7 Flashes DC Bus Overvoltage  Replace Drive   Incoming - >285 VAC  DC Bus - >385 VDC  Fault will reset when voltage is returned. Early VSODU firmware (Before VSODU Rev 41) may not  DC Bus voltage has dropped properly reset this fault. Update T905_O Inverter Fault – below acceptable voltage VSODU firmware to later revision. Yellow 8 Flashes DC Bus Undervoltage  Incoming Voltage <187 VAC   Can occur with power flicker due to  DC Bus Voltage <175 VDC storms, will reset when voltage returns after delay.  Check Incoming Line Voltage to Drive

A906_O Inverter Fault –  Verify Incoming voltage to Drive by  Incoming Voltage >275 VAC Yellow 10 Flashes AC Input Overvoltage  measuring voltage at L1 to L2

A907_O Inverter Fault –  Verify Incoming voltage to Drive by  Incoming voltage <170 VAC Yellow 9 Flashes AC Input Undervoltage  measuring voltage at L1 to L2  Indicates the PIM (Power Inverter Module) on the drive is  Check Outdoor fan operation T908_O Inverter Fault – overheated.  Check Condenser coil for cleanliness Yellow 4 or 18 Flashes PIM Over-temp   May stop or fold back  Check Drive Heat Sink compressor RPM  Indicates the PFC (Power Factor  Check Outdoor fan operation T909_O Inverter Fault – Correction) is overheated.  Check Condenser coil for cleanliness Yellow 5 or 19 Flashes PFC Over-temp  May stop or fold back   Check Drive Heat Sink compressor RPM

EcoNet and Flash Codes Inverter Product

 Verify Compressor Connections at U,  Compressor rotor not matching V, W and Molded plug A910_O Inverter Fault – speed command  System Grossly Overcharged Yellow 2 Flashes Lost Rotor Position   Measured via Back EMF  Compressor Tight or Locked  Drive Defective – Solder Bridging  Verify Compressor Connections at U, T911_O Inverter Fault – V, W and Molded plug  Compressor Current Imbalance Red 14 Flashes Current Imbalance   Check Compressor Windings for significant differences in resistance.

A912_O Inverter Fault –  Hard Reset on Drive  Micro on Drive faulted Red 13 Flashes Micro Fault   If Hard Reset fails, replace Drive

A913_O Inverter Fault -  Power Inverter Module  Replace Drive Red 2 Flashes PIM Sensor Open  temperature sensor is open  Check Incoming Line Voltage at L1 to L2 T914_O Inverter Fault –  Voltage on DC Bus is generally 325 to  DC Bus Voltage is running low Yellow 17 Flashes DC Voltage Low  380VDC.  PIM on Drive Defective  Replace Drive  Verify Operating Superheat and  Compressor Discharge Charge Temperature has exceed 225°F  Check Reversing Valve for leakage T915_O Inverter Fault – degrees and compressor may from Discharge to Suction Yellow 6 Flashes Discharge Temp  fold back until temperature is  Check DLT Sensor Connection to below 200°F Drive  Verify DLT sensor resistance

EcoNet and Flash Codes Inverter Product

 Check Mod Bus Cable A919_O Inverter Fault –  Drive lost internal communication  Hard Reset of Drive Red 9 Flashes PFC/DSP Comm Fault between PFC and DSP   If fault persists - replace drive

 Check Mod Bus Cable A920_O Inverter Fault –  Drive lost internal communication  Hard Reset of Drive Red 8 Flashes COM/DSP Comm Fault between PFC and DSP   If fault persists - replace drive  Verify proper airflow over the heatsink of the drive. Remove any obstructions.. A921_O Inverter Fault –  Sensor to PFC Is either low or  Check the compressor is operating Red 1 Flash PFC Temp Sensor Open open  with in specified limits.  3. If the problem still persists, replace the drive.  Verify proper airflow over the heatsink of the drive. Remove any obstructions.. T922_O Inverter Fault –  Drive has folded back as a result  Check the compressor is operating Yellow 21 Flashes PIM Temp Foldback of PFC temperature  with in specified limits.  3. If the problem still persists, replace the drive.  Incorrect Memory Card has been A925_O Inverter Fault –  Drive size and model data card installed Yellow 22 Flashes Compressor Model Unkown  do not match  Incorrect Inverter Drive has been installed

EcoNet and Flash Codes Inverter Product

A927_O Inverter Fault –  Discharge Line Temperature  Check DLT sensor connection to drive Red 3 Flashes DLT sensor Open  Sensor is open  Check DLT sensor resistance to temp

 This is an indication that the  Check fault history for cause of A928_O Locked system is locked out and needs to lockout condition at control center  be reset  Address fault as indicated in history  Verify Line voltage to unit is on and is measured by reading line voltage into  Drive is either not powered or drive at L1-L2 A929_O 240VAC Missing or Comm there is a problem with the mod  Check Modbus cable between VSODU Failure Red 11 Flashes bus cable between VSODU and and Drive. Closely Examine pins in (Formerly Comm Failure)  Drive connectors  Hard Reset of Drive  Replace Drive

A950_O Configuration Data Restore  Firmware in VSODU is corrupt  Replace Firmware in VSODU Failure

 Possible Damage to solder joints on back of memory card socket on A951_O Memory Card Data Write  VSODU is unable to write data to VSODU

Failure  memory card  Replace VSODU  Replace Memory Card also if VSODU does not resolve

EcoNet and Flash Codes Inverter Product

 Check connection at VSODU T952_O Outside Temperature  Outdoor Temperature Thermistor  Verify leads to sensor are not

Thermistor Failure  is either Open, Shorted or Low pinched, or damaged  Check sensor resistance/temp

A953_O Coil Temperature  Coil Temperature Thermistor is  Check connection at VSODU Thermistor Failure either Open, Shorted or Low  Verify leads to sensor are not

(Formerly called Evap Temperature   Unit will run in cooling mode, but pinched, or damaged Thermistor) will not run in heating mode  Check sensor resistance/temp  Suction Thermistor is either  Check connection at VSODU A954_O Suction Temperature Open, Shorted, or Low  Verify leads to sensor are not

Thermistor Failure   Unit will run in cooling mode but pinched, or damaged will not run in heating mode  Check sensor resistance/temp

 Check connection at VSODU  Suction Thermistor is either T955_O Compressor Temperature  Verify leads to sensor are not Open, Shorted, or Low Thermistor Failure pinched, or damaged   Stator heat will not operate  Check sensor resistance/temp  Check Transducer using formula  Suction Transducer is either,  PSIA= 375*(DCVout/DCVin)-22.8 A956_O Suction Pressure Sensor shorted, grounded or open or  PSIG=PSIA-14.7 Failure  outside of acceptable range  Verify Connections at VSODU and Transucer  Pressure at Transducer has fallen  Check Refrigerant Charge below settings. T957_O Low Refrigerant Pressure  Check for Restrictions in liquid or  50 PSIG for Cooling and 15 PSIG  suction lines, drier, strainers etc. for Heating modes

EcoNet and Flash Codes Inverter Product

 System has tripped the low pressure threshold 3 times in one  Check Refrigerant Charge A957_O Low Refrigerant Pressure call.  Check for Restrictions in liquid or  Unit will be locked out for one suction lines, drier, strainers etc. hour

 System High pressure switch has  Check Refrigerant Charge T958_O High Refrigerant Pressure Yellow 20 Flashes  opened.  Check connection of HPS to Drive

 System High pressure switch has  Check Refrigerant Charge A958_O High Refrigerant Pressure opened 3 times and is locked out Yellow 20 Flashes  Check connection of HPS to Drive  for one hour

 Often times this is a result of short cycling due to envelope protection or pressure switch trips. Flashing  Usually related to overcharge T959_O Compressor Heater On  Indicated only at control center conditions (Normal Operation)   Compressor Sensor not in correct location or not making good surface contact with compressor.  Service Firmware  Compressor Temperature fell  Check refrigerant charge T960_O Compressor Lube below saturated refrigerant  Can happen in extreme cold

Protection pressure indicating liquid is temperatures when compressor slows returning to compressor down from overdrive

EcoNet and Flash Codes Inverter Product

 When Discharge temperature exceeds 225°F, Compressor will slow down to bring discharge temperature down T961_O Compressor Discharge  Folding back due to high below 200°F. Yellow 6 Flashes Temperature High discharge temperature  Check system superheat and charge  Verify reversing valve is not leaking from discharge to suction.

Troubleshooting Notes:

If blower will not run but the thermostat / control center, control board and outdoor equipment is otherwise showing to be powered, check low voltage fuse on air handler control board.

If reversing valve will not shift to heating mode, check fuse on VSODU in addition to solenoid and wiring to reversing valve.

If compressor RPM’s are not as expected, check LED on drive to see if it is folding back as a result of an issue.