Troubleshooting / Eaton VFD faults

Eaton VFD Fault Codes

The fault codes of Eaton AC drives: the PowerXL DC1 text codes and the numbered faults of SVX9000, SPX9000 and DG1. What each one means, which drive uses it, the likely causes, the first checks in order, and how to log it.

How faults show on an Eaton drive

When a DC1 trips, its 7-segment display shows a short text code such as O-I or E-trip, and in default settings the fault relay on terminals 10 and 11 opens. The DC1 keeps its last four trips in parameter P00-13 (P-13 on older units), newest first, with flashing dots marking the older entries, and this log survives a factory reset.

On an SVX9000 or SPX9000 the keypad shows the sequence indication F1, the fault code, a short name and the fault type letter, plus FAULT or ALARM, and the red keypad LED blinks for a real fault; the Active Faults menu M3 holds up to 10 live faults and the Fault History menu M4 keeps the last 30.

A type A alarm only warns and stays on screen for about 30 seconds while the drive keeps running, but an F fault stops the drive until someone resets it. Reset a DC1 with the STOP key, by switching the supply off and on, or with a fresh rising edge on the start input, and reset an SVX9000 or SPX9000 with the STOP or RESET key or a reset signal on the I/O terminals.

Automatic restart is set with P-30 on the DC1 (Auto-1 to Auto-5 tries up to five restarts at 25 second intervals) and through the AR fault type on the 9000X drives, so always remove start signals before you reset.

Safety first.
Eaton warns that the power section of a DC1 stays live for up to five minutes after the supply is switched off while the DC link capacitors discharge, so wait at least 5 minutes before you touch any power terminal.

For SVX9000, SPX9000 and DG1, disconnect all power, wait at least five minutes after every keypad light is off, then confirm with a multimeter set to DC volts that the DC bus capacitors are discharged before opening the drive.

Never make connections while the drive is on line power, and remember that relay outputs can carry outside voltage and an enabled automatic restart can start the motor by itself when power returns. Follow lockout/tagout and your site's safe-work procedures, and check the manual for your exact model before you act.

Quick lookup

Faults trip the drive and stop the motor, so in OEE they are availability losses; warnings let the drive keep running until you act.

Type a code or a word (overcurrent, overvoltage, earth fault, overtemperature) to filter the list. DC1 shows text codes, SVX9000, SPX9000 and DG1 show F numbers, and where DG1 treats a number differently it has its own row.

59 codes

CodeTypeName
OI-bFaultBrake channel overcurrent (error 01)
OL-brFaultBrake resistor thermal overload (error 02)
O-IFaultOutput overcurrent (error 03)
I.t-trPFaultMotor overload, I x t trip (error 04)
PS-trpFaultHardware overcurrent, power stage trip (error 05)
O.VoltFaultDC link overvoltage (error 06)
U.VoltFaultDC link undervoltage (error 07)
O-tFaultHeatsink overtemperature (error 08)
U-tFaultUnder temperature (error 09)
P-dEfFaultFactory defaults loaded (error 10)
E-tripFaultExternal trip (error 11)
SC-0bSFaultSerial communication lost (error 12)
P-LOssFaultInput phase loss (error 14)
hO-IFaultFast (instantaneous) output overcurrent (error 15)
th-FltFaultHeatsink thermistor fault (error 16)
dAtA-FFaultInternal memory error (error 17)
4-20 FFaultAnalog input current out of range (error 18)
F-PtcFaultMotor PTC thermistor trip (error 21)
FAn-FFaultCooling fan fault (error 22, IP66 only)
O-hEAtFaultDrive internal or ambient overtemperature (error 23)
AtF-01 to AtF-05FaultMotor identification failed (errors 40 to 44)
Out-PhFaultOutput (motor) phase loss (error 49)
SC-F01FaultModbus communication loss (error 50)
SC-trpFaultSerial communication lost
Out-FFaultDrive output fault, output stage trip
F1FaultOvercurrent
F2FaultOvervoltage
F3FaultEarth (ground) fault
F5FaultCharging switch
F6FaultEmergency stop
F7FaultSaturation trip
F8FaultSystem fault
F9FaultUndervoltage
F10FaultInput line supervision
F11FaultOutput phase supervision
F12FaultBrake chopper supervision
F13FaultDrive undertemperature
F13WarningDrive undertemperature (DG1)
F14FaultDrive overtemperature
F15FaultMotor stalled
F16FaultMotor overtemperature
F16WarningMotor overtemperature (DG1)
F17FaultMotor underload
F22FaultEEPROM checksum fault
F25FaultMicroprocessor watchdog fault
F26FaultStartup prevented
F29FaultThermistor fault
F32FaultFan cooling
F41FaultIGBT temperature
F42FaultBrake resistor overtemperature
F50FaultAnalog input below 4 mA
F51FaultExternal fault
F53FaultCommunication bus fault
F54FaultSlot fault
F57FaultMotor ID fault (DG1)
F63FaultCurrent unbalance (DG1)
F66FaultSafe Torque Off (DG1)
F67WarningCurrent limit control (DG1)
F68WarningOvervoltage control (DG1)

Each code: causes and first checks

OI-b: Brake channel overcurrent (error 01)

Hits OEE: Availability

What it means: The braking transistor saw far too much current, so the drive tripped to protect itself. It almost always points at the brake resistor circuit.[1][2][4]

Also on: DC1 (DC1...E1, DC1...20, DC1...OE1 and older DC1)

Likely causes

  • Short circuit or ground fault in the brake resistor or its wiring
  • Brake resistor value lower than the minimum allowed for this drive

First checks, in this order

  1. Switch off, wait 5 minutes and inspect the brake resistor cables for damage, shorts and ground faults
  2. Measure the brake resistor and compare it with the minimum resistance in the DC1 manual
  3. Replace the resistor or wiring before you reset and run again

OL-br: Brake resistor thermal overload (error 02)

Hits OEE: Availability

What it means: The drive stopped to keep the brake resistor from burning up. It only appears when the internal brake chopper protection is active (P-34 = 1).[1][2]

Also on: DC1 (DC1...E1, DC1...20, DC1...OE1)

Likely causes

  • Deceleration ramps (P-04, P-24) so short that the drive brakes too often
  • High load inertia feeding a lot of energy back
  • Internal resistor protection not matched to the resistor actually fitted

First checks, in this order

  1. Make the P-04 and P-24 ramp times longer
  2. Reduce the load inertia if the machine allows it
  3. If the internal protection does not suit your resistor, fit external resistor protection and set P-34 to 2

O-I: Output overcurrent (error 03)

Hits OEE: Availability

What it means: Current at the drive output went too high and the drive tripped. When it happens (at power on, at start, at steady speed or on a ramp) tells you where to look.[1][2][3][4]

Also on: DC1 (DC1...E1, DC1...20, DC1...OE1 and older DC1)

Likely causes

  • Bad motor cable, shorted motor turns or a ground fault (trips right at enable)
  • Motor blocked, mechanical brake not releasing, wrong star/delta link or wrong motor current in P-08 (trips at start)
  • Motor overloaded (trips at constant speed)
  • Acceleration or deceleration ramps too short for the load

First checks, in this order

  1. Note exactly when the trip happens
  2. Check the motor cable and motor windings for shorts and ground faults
  3. Make sure the motor turns freely and the brake releases
  4. Check P-08 against the nameplate and the star/delta wiring
  5. Lengthen the ramp (P-03) and lower the voltage boost (P-11) if needed

I.t-trP: Motor overload, I x t trip (error 04)

Hits OEE: Availability

What it means: The drive's motor thermal model tripped because the motor ran above the rated current set in P-08 for too long. Flashing dots on the display while running are the early warning.[1][2][3][5]

Also on: DC1 (DC1...E1, DC1...20, DC1...OE1 and older DC1)

Likely causes

  • Motor rated current in P-08 entered wrong
  • Wrong star/delta connection
  • Machine jammed or carrying extra load
  • Acceleration ramp too short

First checks, in this order

  1. Compare P-08 with the motor nameplate
  2. Check the motor connection (star/delta)
  3. Check the machine turns freely with no jams or blockages
  4. Lengthen the acceleration ramp (P-03) or reduce the load

PS-trp: Hardware overcurrent, power stage trip (error 05)

Hits OEE: Availability

What it means: The power stage hardware protection tripped on a very fast current spike. If it comes back with the motor disconnected, the drive itself is damaged.[1][2][3][4]

Also on: DC1 (DC1...E1, DC1...20, DC1...OE1 and older DC1)

Likely causes

  • Short circuit or ground fault in the motor or motor cable
  • Failed drive power stage

First checks, in this order

  1. Check the motor and motor cable for shorts and ground faults
  2. Disconnect the motor cable and switch the drive back on
  3. If the trip remains, replace the drive, and find the short or ground fault that may have caused it before fitting the new one

O.Volt: DC link overvoltage (error 06)

Hits OEE: Availability

What it means: The DC link voltage went above its limit. Most often the motor pushes energy back into the drive while it slows a heavy load down.[1][2][4]

Also on: DC1 (DC1...E1, DC1...20, DC1...OE1 and older DC1)

Likely causes

  • Supply voltage above the range the drive is rated for
  • Deceleration ramp too short for the load
  • Brake resistor missing or braking chopper not enabled

First checks, in this order

  1. Measure the supply voltage and compare it with the drive rating
  2. Lengthen the deceleration ramp (P-04 / P-24)
  3. Fit a brake resistor and enable the braking chopper with P-34 (frame sizes FS2, FS3 and FS4 only)

U.Volt: DC link undervoltage (error 07)

Hits OEE: Availability

What it means: The DC link voltage fell below its limit. Seeing it right after switching the supply off is normal; it only matters when it appears while the drive is running.[1][2][5]

Also on: DC1 (DC1...E1, DC1...20, DC1...OE1 and older DC1)

Likely causes

  • Supply voltage too low
  • Loose or high resistance connection in the feeder (breaker, contactor, choke)

First checks, in this order

  1. Ask whether the power was just switched off; if so, ignore it
  2. Measure the supply voltage while the drive runs
  3. Check every breaker, contactor and choke in the feeder for good, tight connections

O-t: Heatsink overtemperature (error 08)

Hits OEE: Availability

What it means: The drive's heatsink got too hot and the drive tripped. The cabinet is too warm or the cooling air cannot flow.[1][2][4]

Also on: DC1 (DC1...E1, DC1...20, DC1...OE1 and older DC1)

Likely causes

  • Ambient above the limit (IP20 units 50 °C, IP66 units 40 °C)
  • Too little clearance above and below the drive
  • Vents blocked by dirt or by devices mounted too close
  • Drive fan stopped, switching frequency or load too high (older DC1 manual)

First checks, in this order

  1. Measure the air temperature around the drive
  2. Clean the vents and restore the clearances above and below
  3. Check the drive fan runs
  4. Improve cabinet ventilation, then lower the switching frequency or the load if it still trips

U-t: Under temperature (error 09)

Hits OEE: Availability

What it means: The ambient temperature is below -10 °C, so the drive refuses to start. It runs again once it warms above that.[1][2][4]

Also on: DC1 (DC1...E1, DC1...20, DC1...OE1 and older DC1)

Likely causes

  • Drive installed in an unheated or outdoor location
  • Cold start after a frosty night or weekend

First checks, in this order

  1. Measure the temperature at the drive
  2. Warm the cabinet above -10 °C before starting

P-dEf: Factory defaults loaded (error 10)

Hits OEE: Availability

What it means: All parameters were set back to factory defaults, and the drive logs this as a fault. Your motor data and settings are gone until you enter them again.[1][2][4]

Also on: DC1 (DC1...E1, DC1...20, DC1...OE1 and older DC1)

Likely causes

  • Someone loaded the default parameter set
  • An internal memory error (dAtA-F) reloaded the defaults

First checks, in this order

  1. Press STOP to clear the message
  2. Re-enter the motor data and application settings from your records
  3. Check P00-13 for a dAtA-F entry next to it

E-trip: External trip (error 11)

Hits OEE: Availability

What it means: The input set as External Fault went low, and the drive will only run with a high signal there. Often a motor thermistor or a safety device is wired to it.[1][2][4]

Also on: DC1 (DC1...E1, DC1...20, DC1...OE1 and older DC1)

Likely causes

  • External device or interlock opened the circuit
  • Motor thermistor on that input reports a hot motor
  • Broken wire on the external fault input

First checks, in this order

  1. Find what is wired to the input: DI3, terminal 4 on DC1...E1, ...20 and ...OE1 (the older 04/16 DC1 manual names DI5, terminal 10)
  2. If a thermistor is connected, check whether the motor is too hot
  3. Check the wiring and that the input sees a high signal

SC-0bS: Serial communication lost (error 12)

Hits OEE: Availability

What it means: The drive lost its serial link to other drives or external modules on the bus.[1][2]

Also on: DC1 (DC1...E1, DC1...20, DC1...OE1)

Likely causes

  • Bus connection to other drives or modules faulty
  • Two or more modules on the bus set to the same address

First checks, in this order

  1. Check the communication cable and plugs
  2. Make sure every drive and module on the bus has its own unique address

P-LOss: Input phase loss (error 14)

Hits OEE: Availability

What it means: One of the incoming supply phases failed. This only applies to DC1 units with a three phase supply.[1][2][6]

Also on: DC1 (DC1...E1, DC1...20, DC1...OE1 and older DC1)

Likely causes

  • One supply phase missing, for example a blown fuse
  • A supply phase low or badly connected

First checks, in this order

  1. Measure all three phase voltages at the drive input
  2. Check the fuses, breaker, cables and terminal connections on the supply side

hO-I: Fast (instantaneous) output overcurrent (error 15)

Hits OEE: Availability

What it means: An instant current spike at the output tripped the drive. Eaton treats it the same as O-I, and it also has a growing reset delay.[1][2][5]

Also on: DC1 (DC1...E1, DC1...20, DC1...OE1)

Likely causes

  • Short circuit or ground fault in motor or motor cable
  • Motor blocked or brake not released
  • Wrong motor current in P-08 or wrong star/delta link
  • Ramps too short

First checks, in this order

  1. Check the cable and motor windings for shorts and ground faults
  2. Make sure the motor turns freely and the brake releases
  3. Check P-08 and the star/delta wiring
  4. Lengthen P-03 and lower the boost in P-11

th-Flt: Heatsink thermistor fault (error 16)

Hits OEE: Availability

What it means: The drive's own heatsink temperature sensor is faulty, so it cannot protect itself. This is a hardware problem inside the drive.[1][2][4]

Also on: DC1 (DC1...E1, DC1...20, DC1...OE1 and older DC1)

Likely causes

  • Faulty heatsink thermistor
  • Internal drive hardware fault

First checks, in this order

  1. Write down the fault log (P00-13)
  2. Contact your Eaton sales branch or service partner for repair or replacement

dAtA-F: Internal memory error (error 17)

Hits OEE: Availability

What it means: The drive could not save its parameters, so it loaded factory defaults. Your settings need to go back in.[1][2][3]

Also on: DC1 (DC1...E1, DC1...20, DC1...OE1 and older DC1)

Likely causes

  • Parameter save to internal memory failed
  • Internal memory fault if it keeps coming back

First checks, in this order

  1. Enter the parameter values again and save them
  2. If the message returns, contact your Eaton sales branch

4-20 F: Analog input current out of range (error 18)

Hits OEE: Availability

What it means: The current on an analog input is outside the range it is set for. On a 4-20 mA signal this usually means a broken wire.[1][2][3]

Also on: DC1 (DC1...E1, DC1...20, DC1...OE1 and older DC1)

Likely causes

  • Broken wire on the 4-20 mA setpoint signal
  • Input range setting (P-16 for AI1, P-47 for AI2) not matching the signal

First checks, in this order

  1. Measure the mA signal at the drive terminals
  2. Check the setpoint wiring for breaks
  3. Check P-16 and P-47 match the signal type

F-Ptc: Motor PTC thermistor trip (error 21)

Hits OEE: Availability

What it means: The motor thermistor reports an overheated motor. On DC1...E1 the drive trips above about 2.5 kOhm and can be reset below 1.9 kOhm.[1][2][8]

Also on: DC1 (DC1...E1, DC1...20, DC1...OE1)

Likely causes

  • Motor overheating from load or poor cooling
  • Thermistor wiring fault

First checks, in this order

  1. Let the motor cool and check its load and cooling
  2. Check the thermistor cable connections and the motor

FAn-F: Cooling fan fault (error 22, IP66 only)

Hits OEE: Availability

What it means: The internal cooling fan of an IP66 DC1 failed. Without it the drive will soon overheat.[1][2]

Also on: DC1 (DC1...E1, DC1...20, DC1...OE1, IP66 units)

Likely causes

  • Cooling fan failed or stopped
  • Fan worn out and due for replacement

First checks, in this order

  1. Check the fan turns when the drive runs
  2. Replace the cooling fan

O-hEAt: Drive internal or ambient overtemperature (error 23)

Hits OEE: Availability

What it means: The temperature inside the drive, or around it, is too high. It differs from O-t, which watches the heatsink.[1][2]

Also on: DC1 (DC1...E1, DC1...20, DC1...OE1)

Likely causes

  • Too little cooling air reaching the drive
  • Cabinet or ambient temperature too high

First checks, in this order

  1. Check the cooling air path and cabinet ventilation
  2. Measure the cabinet temperature and bring it down

AtF-01 to AtF-05: Motor identification failed (errors 40 to 44)

Hits OEE: Availability

What it means: The motor identification (autotune) run did not finish. AtF-02 means stator resistance measured too high, AtF-03 inductance too low, AtF-04 inductance too high and AtF-05 motor values that do not match.[1][2]

Also on: DC1 (DC1...E1, DC1...20, DC1...OE1)

Likely causes

  • Measured stator resistance too large (AtF-02)
  • Measured motor inductance too low or too high (AtF-03, AtF-04)
  • Measured motor values do not match the entered data (AtF-05)

First checks, in this order

  1. Check the motor data entered against the nameplate
  2. Check the motor cable connections at drive and motor
  3. Run the identification again with the motor cold and connected

Out-Ph: Output (motor) phase loss (error 49)

Hits OEE: Availability

What it means: One phase of the motor cable is not connected or is broken. The motor cannot run properly on two phases.[1][2]

Also on: DC1 (DC1...E1, DC1...20, DC1...OE1)

Likely causes

  • Loose or unconnected motor terminal at drive or motor
  • Broken conductor in the motor cable

First checks, in this order

  1. Switch off, wait 5 minutes, then check U, V and W terminals at the drive and the motor
  2. Check continuity of each motor cable core

SC-F01: Modbus communication loss (error 50)

Hits OEE: Availability

What it means: The drive tripped because Modbus RTU traffic stopped for longer than the timeout. SC-F02 (error 51) is the same trip for CANopen.[1][2]

Also on: DC1 (DC1...E1, DC1...20, DC1...OE1)

Likely causes

  • Faulty incoming Modbus RTU (or CAN) cable
  • Master not polling at least one register within the timeout set in P-36 index 3

First checks, in this order

  1. Check the incoming Modbus or CAN cable
  2. Check the PLC or master polls the drive cyclically within the P-36 index 3 timeout

SC-trp: Serial communication lost

Hits OEE: Availability

What it means: The drive lost communication with other drives or devices on its serial network. Eaton lists it with the same advice as SC-0bS.[2][3]

Also on: DC1 (DC1 parameter manual 11/16, DC1...E1 where it is spelled SC-trip)

Likely causes

  • Network connection to other drives or devices faulty
  • Two devices on the network with the same address

First checks, in this order

  1. Check the network cable and connections
  2. Give every device on the network its own unique address

Out-F: Drive output fault, output stage trip

Hits OEE: Availability

What it means: The drive's output stage protection tripped. Eaton groups it with the fast overcurrent trip, so treat it like an instant overcurrent at the output.[5]

Also on: DC1 (DC1...E1)

Likely causes

  • Instantaneous overcurrent at the drive output
  • Short circuit or ground fault in motor cable or windings
  • Motor blocked, brake not released or wrong motor current in P-08

First checks, in this order

  1. Check the cable between drive and motor
  2. Check the motor windings for shorts and ground faults
  3. Make sure the motor turns freely and the brake releases
  4. Lengthen P-03 and check P-08

F1: Overcurrent

Hits OEE: Availability

What it means: The drive measured output current above four times its rated current and tripped.[6][7]

Also on: SVX9000, SPX9000, DG1

Likely causes

  • Sudden heavy load increase
  • Short circuit in the motor
  • Short circuit in the motor cables
  • Unsuitable motor

First checks, in this order

  1. Check the load and the mechanics
  2. Check the motor
  3. Check the motor cables and connections
  4. On DG1 also check ramp times and run a motor identification

F2: Overvoltage

Hits OEE: Availability

What it means: The DC link voltage went above its high limit. Usually the motor feeds energy back while slowing down, or the supply has spikes.[6][7]

Also on: SVX9000, SPX9000, DG1

Likely causes

  • Deceleration time too short
  • High voltage or surges on the supply
  • Brake chopper disabled (DG1)
  • Start and stop sequence too fast (DG1)

First checks, in this order

  1. Make the deceleration time longer
  2. Use a brake chopper and brake resistor
  3. Check the supply voltage is not too high
  4. Add input impedance to limit surges, or activate the overvoltage controller on DG1

F3: Earth (ground) fault

Hits OEE: Availability

What it means: The drive found that the motor phase currents do not add up to zero, so current is leaking to earth. The response can be programmed in the application.[6][7]

Also on: SVX9000, SPX9000, DG1

Likely causes

  • Insulation failure in the motor
  • Insulation failure in the motor cables

First checks, in this order

  1. Disconnect the motor cable at the drive output (U, V, W) before any test
  2. Insulation test the motor and the motor cable
  3. Never megger the drive itself

F5: Charging switch

Hits OEE: Availability

What it means: The DC bus charging switch was still open when the start command came.[6][7]

Also on: SVX9000, SPX9000, DG1

Likely causes

  • Faulty operation
  • Component failure

First checks, in this order

  1. Reset the fault and restart
  2. If it comes back, contact your Eaton distributor

F6: Emergency stop

Hits OEE: Availability

What it means: An emergency stop signal arrived on a digital input. On DG1 an open STO terminal also gives this code.[6][7]

Also on: SVX9000, SPX9000, DG1

Likely causes

  • Emergency stop signal from a digital input
  • STO terminal open on the control board (DG1)

First checks, in this order

  1. Find out why the emergency stop was triggered and fix it
  2. Remove the signal from the input, or close the STO circuit on DG1
  3. Reset the fault

F7: Saturation trip

Hits OEE: Availability

What it means: The output transistors saturated, which points to a damaged power component or a hard short. It cannot be reset from the keypad.[6][7]

Also on: SVX9000, SPX9000, DG1

Likely causes

  • Defective component (IGBT module)
  • Short circuit in the motor or motor cable

First checks, in this order

  1. Switch off the power; the keypad cannot reset this
  2. Check the motor and motor cables, especially if F1 appeared at the same time
  3. If motor and cables are fine, do not reconnect power and contact your Eaton distributor
  4. On DG1 also check the EMC screw is installed

F8: System fault

Hits OEE: Availability

What it means: An internal system fault was detected. The fault time data record holds extra detail.[6]

Also on: SVX9000, SPX9000

Likely causes

  • Component failure
  • Faulty operation

First checks, in this order

  1. Read the fault time data record in the Active Faults menu
  2. Reset the fault and restart
  3. If it comes back, contact your Eaton distributor

F9: Undervoltage

Hits OEE: Availability

What it means: The DC link voltage fell below the minimum safe level. On DG1 this fault is only active while the drive is running.[6][7]

Also on: SVX9000, SPX9000, DG1

Likely causes

  • Supply voltage too low or a short supply dip
  • Drive internal fault
  • Defective input fuse or external charge switch not closed (DG1)

First checks, in this order

  1. If the supply dipped, reset the fault and restart
  2. Measure the supply voltage
  3. If the supply was within spec, an internal failure is likely: contact your Eaton distributor

F10: Input line supervision

Hits OEE: Availability

What it means: One input phase is low or missing.[6][7]

Also on: SVX9000, SPX9000, DG1

Likely causes

  • Missing supply phase, for example a blown fuse
  • Low supply phase or bad cable connection

First checks, in this order

  1. Measure the supply voltage on all phases
  2. Check fuses, cables and connections

F11: Output phase supervision

Hits OEE: Availability

What it means: Current is missing in one motor phase. A motor lead or winding is open.[6][7]

Also on: SVX9000, SPX9000, DG1

Likely causes

  • Broken or loose motor cable or terminal
  • Fault in the motor

First checks, in this order

  1. Check the motor cables and connections at both ends
  2. Check the motor windings

F12: Brake chopper supervision

Hits OEE: Availability

What it means: The brake chopper circuit is not working as expected.[6][7]

Also on: SVX9000, SPX9000, DG1

Likely causes

  • Brake resistor not installed
  • Brake resistor open or broken
  • Brake chopper failure

First checks, in this order

  1. Check the brake resistor and its cabling
  2. If the resistor is fine, the chopper is faulty: contact your Eaton distributor

F13: Drive undertemperature

Hits OEE: Availability

What it means: The heatsink is colder than -10 °C (14 °F), so the drive trips.[6]

Also on: SVX9000, SPX9000

Likely causes

  • Drive installed in a cold, unheated location
  • Cold start after a frosty night

First checks, in this order

  1. Read the unit temperature
  2. Add heating or move the drive to a warmer place

F13: Drive undertemperature (DG1)

Warning: act before it becomes a stop

What it means: On the DG1, code 13 means the heatsink or board is colder than -10 °C, and by default it only warns. The response is configurable (No Action, Warning, Fault or Fault coast).[7]

Also on: DG1

Likely causes

  • Heatsink temperature under -10 °C
  • Drive in a cold cabinet or outdoor location

First checks, in this order

  1. Read the unit temperature on the keypad
  2. Warm the cabinet or start in cold weather mode
  3. Check the fault response setting if you want it to stop the drive

F14: Drive overtemperature

Hits OEE: Availability

What it means: The heatsink went above 90 °C (194 °F) and the drive tripped. On SVX9000 and SPX9000 a warning comes first at 85 °C (185 °F).[6][7]

Also on: SVX9000, SPX9000, DG1

Likely causes

  • Too little or blocked cooling air
  • Dust or dirt on the heatsink
  • High ambient temperature
  • Switching frequency too high for the ambient and motor load

First checks, in this order

  1. Check the amount and flow of cooling air
  2. Clean the heatsink
  3. Check the highest ambient temperature
  4. Lower the switching frequency

F15: Motor stalled

Hits OEE: Availability

What it means: The stall protection detected a motor that is not turning as it should. The response can be programmed in the application.[6][7]

Also on: SVX9000, SPX9000 (DG1 uses code 15 for the same thing, but its default response is No Action)

Likely causes

  • Motor or load mechanical failure
  • Load too high
  • Stall protection settings wrong

First checks, in this order

  1. Check the motor, the mechanics and the load
  2. Confirm the stall parameter settings

F16: Motor overtemperature

Hits OEE: Availability

What it means: The drive's motor temperature model calculated that the motor is overheating. The response can be programmed in the application.[6]

Also on: SVX9000, SPX9000

Likely causes

  • Motor overloaded
  • Motor temperature model parameters set wrong

First checks, in this order

  1. Reduce the motor load
  2. If the motor is not overloaded, check the temperature model parameters

F16: Motor overtemperature (DG1)

Warning: act before it becomes a stop

What it means: On the DG1, code 16 means the motor is too hot, based on the drive's estimate or on temperature feedback. Its default response is No Action, so it only shows when someone set it to Warning or Fault.[7]

Also on: DG1

Likely causes

  • Motor overloaded
  • Temperature model parameters set wrong

First checks, in this order

  1. Reduce the motor load
  2. Check the temperature model parameters
  3. Check the configured response for this fault

F17: Motor underload

Hits OEE: Availability

What it means: The motor is carrying much less load than expected, which often means a broken drive train. The response can be programmed in the application.[6][7]

Also on: SVX9000, SPX9000 (DG1 uses code 17 for the same thing, but its default response is No Action)

Likely causes

  • Mechanical or load problem such as a loose belt or broken coupling
  • Underload parameter settings wrong

First checks, in this order

  1. Check for a loose belt, broken coupling or load problem
  2. Confirm the underload parameter settings

F22: EEPROM checksum fault

Hits OEE: Availability

What it means: The drive could not save its parameters correctly. After reset it reloads factory defaults.[6]

Also on: SVX9000, SPX9000

Likely causes

  • Faulty operation
  • Component failure

First checks, in this order

  1. Reset the fault; the drive reloads default settings
  2. Check and re-enter all parameter settings
  3. If it comes back, contact your Eaton distributor

F25: Microprocessor watchdog fault

Hits OEE: Availability

What it means: The processor watchdog timed out, so the control electronics stopped the drive.[6][7]

Also on: SVX9000, SPX9000, DG1

Likely causes

  • Faulty operation
  • Component failure

First checks, in this order

  1. Reset the fault and restart, or cycle power on DG1
  2. Update the drive software on DG1
  3. If it comes back, contact your Eaton distributor

F26: Startup prevented

Hits OEE: Availability

What it means: The drive was blocked from starting by its start enable or interlock logic.[6][7]

Also on: SVX9000, SPX9000, DG1

Likely causes

  • Start enable or interlock signal missing
  • Interlock signal took longer than the set time (DG1)

First checks, in this order

  1. Check the start enable and interlock settings and signals
  2. Stop the drive and give the start command again

F29: Thermistor fault

Hits OEE: Availability

What it means: The thermistor input on an option board detected a hot motor. On DG1 it trips when the thermistor resistance goes above 4.7 kOhm.[6][7]

Also on: SVX9000, SPX9000, DG1

Likely causes

  • Motor overheating from load or poor cooling
  • Thermistor wiring open or shorted
  • Unused thermistor input left open

First checks, in this order

  1. Check the motor cooling and motor load
  2. Check the thermistor connection
  3. If the thermistor input is not used, short-circuit it

F32: Fan cooling

Hits OEE: Availability

What it means: The drive's cooling fan did not start when it was commanded.[6][7]

Also on: SVX9000, SPX9000, DG1

Likely causes

  • Fan damaged or stalled
  • Fan supply (24 V DC) or fan wiring fault (DG1)

First checks, in this order

  1. Check the fan and its wires
  2. On DG1 verify 24 V DC reaches the fan
  3. Contact your Eaton distributor for a replacement fan

F41: IGBT temperature

Hits OEE: Availability

What it means: The output transistor bridge protection detected a high short-term overload and tripped. F31 is the hardware version of the same protection.[6][7]

Also on: SVX9000, SPX9000, DG1

Likely causes

  • Output overload
  • Motor too large for the drive
  • Switching frequency too high (DG1)

First checks, in this order

  1. Check the loading
  2. Check the motor size against the drive
  3. Decrease the switching frequency

F42: Brake resistor overtemperature

Hits OEE: Availability

What it means: The brake resistor protection detected too much braking and tripped the drive.[6]

Also on: SVX9000, SPX9000

Likely causes

  • Excessive braking duty
  • Deceleration time too short for the brake resistor

First checks, in this order

  1. Set a longer deceleration time
  2. Use an external brake resistor

F50: Analog input below 4 mA

Hits OEE: Availability

What it means: Current on an analog input set for 4 to 20 mA dropped below 4 mA, so the signal is lost. The response can be programmed in the application.[6][7]

Also on: SVX9000, SPX9000 (DG1 uses code 50 for the same thing, but its default response is No Action)

Likely causes

  • Control cable broken or loose
  • Signal source failed

First checks, in this order

  1. Check the current loop with a meter
  2. Check the signal source
  3. Check the wiring

F51: External fault

Hits OEE: Availability

What it means: A digital input set as an external fault input was triggered. DG1 also has codes 92 and 93 for external fault 2 and 3.[6][7]

Also on: SVX9000, SPX9000, DG1

Likely causes

  • External device triggered the fault input
  • Digital input setting or signal level wrong

First checks, in this order

  1. Find the source of the trigger
  2. Check the digital input settings and the input level

F53: Communication bus fault

Hits OEE: Availability

What it means: The link between the fieldbus master and the drive's communication board failed.[6]

Also on: SVX9000, SPX9000

Likely causes

  • Fieldbus installation fault
  • Communication board or master problem

First checks, in this order

  1. Check the fieldbus installation
  2. If the installation is correct, contact your Eaton distributor

F54: Slot fault

Hits OEE: Availability

What it means: An option board or its slot is defective.[6][7]

Also on: SVX9000, SPX9000, DG1

Likely causes

  • Defective option board
  • Defective slot
  • Board not properly seated

First checks, in this order

  1. Check the board is properly installed and seated
  2. On DG1 check Board Status on the keypad
  3. If the installation is correct, contact your Eaton distributor

F57: Motor ID fault (DG1)

Hits OEE: Availability

What it means: The motor identification run did not complete successfully.[7]

Also on: DG1

Likely causes

  • Motor size not suited to the drive
  • Input or output wiring not connected properly

First checks, in this order

  1. Check the motor size against the drive
  2. Verify the input and output wiring
  3. Run the identification again

F63: Current unbalance (DG1)

Hits OEE: Availability

What it means: The output current is unbalanced between the motor phases.[7]

Also on: DG1

Likely causes

  • Motor wiring fault
  • Uneven output voltage from the drive

First checks, in this order

  1. Check the motor wiring
  2. Check the drive output voltage on all three phases
  3. If it continues, contact your distributor

F66: Safe Torque Off (DG1)

Hits OEE: Availability

What it means: The STO safety input opened, so the drive blocked its output.[7]

Also on: DG1

Likely causes

  • STO safety circuit triggered
  • STO wiring fault

First checks, in this order

  1. Reset the STO trigger (safety device)
  2. Verify the STO wiring
  3. Reset the fault once the input is enabled again

F67: Current limit control (DG1)

Warning: act before it becomes a stop

What it means: The output current reached the current limit, so the drive holds back while it keeps running. A line that runs slow with this warning is being limited, not faulted.[7]

Also on: DG1

Likely causes

  • Load too heavy
  • Acceleration time too short

First checks, in this order

  1. Check the load
  2. Set a longer acceleration time

F68: Overvoltage control (DG1)

Warning: act before it becomes a stop

What it means: The DC link voltage reached its limit and the overvoltage controller is acting while the drive keeps running.[7]

Also on: DG1

Likely causes

  • Input voltage high
  • Acceleration or deceleration time too short

First checks, in this order

  1. Check the input voltage
  2. Set longer acceleration and deceleration times

Log it, or the same alarm comes back

A drive fault stops the motor and with it the conveyor, pump or fan the line depends on, so in OEE terms it is a breakdown. Log the code, the drive and the minutes lost.

  • Reason code: the code plus the drive, for example DC1 O.Volt, pump 2, so an overvoltage that trips on every fast stop stands out.
  • Loss bucket: a stop that needs a reset, a part or a technician is an availability loss (breakdown). Stops shorter than your micro-stop threshold go to performance (minor stops). The six big losses page shows where each one belongs.
  • What to count: how often each code fires per week and the minutes it costs. Two numbers a week turn "that alarm comes up sometimes" into a ranked list. The MTBF and MTTR calculator and the downtime cost calculator do the math.

The free OEE tracker logs each stop with its reason and turns the week into a downtime Pareto, so the code that costs the most rises to the top.

For drive faults across brands, fabrico.io has a VFD fault codes guide. A fault code tells you what the drive measured, not what happened at the machine in the seconds before. Fabrico's camera-based OEE software syncs line camera video with machine data, so you can replay the moment the line stopped next to the trip.

Frequently asked questions

How do I reset a fault on an Eaton DC1 drive?

Fix the cause first, then press the STOP key, switch the supply off and on, or give a fresh rising edge on the start input (DI1 or DI2). Over Modbus or CANopen you can set the reset bit in the control word. After O-I, hO-I or I.t-trP the drive makes you wait before a reset works, starting at 2 seconds and getting longer with each repeat trip.

Why does my DC1 show U-Volt every time I switch it off?

U-Volt means the DC link voltage dropped below its limit, which is exactly what happens when the supply is switched off and the capacitors drain. Eaton says this is normal in that case. It only points to a problem if it appears while the drive is running; then check the supply voltage and the breaker, contactor and choke connections.

Where do I find the fault history on an SVX9000 or SPX9000?

Open the Fault History menu M4 on the keypad and scroll with the browser buttons; it keeps up to 30 faults and drops the oldest first. Each entry has a fault time data record (T.1 to T.13) with output frequency, motor current, DC bus voltage, unit temperature and more from the moment of the trip. Holding ENTER for three seconds clears the whole history, so write it down first.

What is the difference between A, F, AR and FT faults on the 9000X drives?

A is an alarm: the drive keeps running and the message stays for about 30 seconds. F stops the drive until someone resets it. AR stops the drive, resets itself and tries to restart, and if that restart fails the drive goes to FT, which stays stopped like an F fault.

Can I make an Eaton DC1 restart by itself after a trip?

Yes, set P-30 Start Mode to Auto-1 up to Auto-5 and the drive tries up to five restarts at 25 second intervals before it locks out and needs a manual reset. It only works when the drive is controlled from the terminals. Eaton warns that the motor can then start on its own, so make sure that is safe for the machine and the people near it.

Sources

Codes and meanings follow the manufacturer documentation below. Wording is ours, simplified for the shop floor; the manual for your exact model and software version wins if it differs.

  1. Eaton PowerXL DC1...20... and DC1...OE1 Variable Frequency Drives Installation Manual, MN040059EN (02/20)
  2. Eaton PowerXL DC1...E1 Variable Frequency Drives Parameter Manual, MN040022EN (05/22)
  3. Eaton PowerXL DC1 Variable Frequency Drives Parameter Manual, MN04020004Z-EN (11/16)
  4. Eaton PowerXL DC1 Variable Frequency Drives Installation Manual, MN04020003Z-EN (04/16)
  5. Eaton Application Note AP040054EN, PowerXL DC1...E1 Variable Frequency Drives: Starting, Stopping and Operation (07/2018)
  6. Eaton 9000X AF Drives User Manual (SVX9000 / SPX9000), MN04001004E (May 2011)
  7. Eaton PowerXL DG1 Series Adjustable Frequency Drives Application Manual, MN040004EN (October 2016)
  8. Eaton Application Note AP040057EN, PowerXL DC1...E1 Variable Frequency Drives: I/O Configuration (01/2017)

See the moment the drive tripped

Fabrico, a light MES with computer vision, syncs camera footage with machine and timeline data, so you can replay the exact moment the line stopped and review the cause next to the drive's fault. Cameras also catch short stops and a line that is switched on but not producing, the losses nobody writes down. Machines connect through a PLC, a Fabrico IoT device or an AI camera.

Book a Fabrico demo
The lookup stays free.

Related: VFD drive troubleshooting · electric motor · Delta VFD fault codes · Yaskawa V1000 codes

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Related tools: full troubleshooting directory · OEE calculator · downtime cost · MTBF / MTTR · glossary

OEE essentials: OEE calculator · What is OEE · How to improve OEE · Six big losses · Availability · TEEP · Cost of downtime · OEE benchmark · Free OEE tracker · Free OEE software · How to track downtime · How to implement OEE · Light MES vs full MES