Troubleshooting / SINAMICS G120 codes

Siemens SINAMICS G120 Fault and Alarm Codes

The F fault and A alarm codes of Siemens SINAMICS G120 drives (CU240E-2 and PM240-2) and the G120C: what each one means, the likely causes, the first checks in order, how to acknowledge it, and how to log it so the same stop stops coming back.

How SINAMICS shows faults and alarms

An F code (Fxxxxx) is a fault: the drive runs its stop reaction, sets bit 3 of status word 1 (r0052) and the fault must be acknowledged, while an A code (Axxxxx) is an alarm that sets bit 7, leaves the motor running and clears itself once the cause is gone.

The BOP-2 or IOP-2 panel shows the code as Fxxxxx or Axxxxx, the RDY LED on the Control Unit turns red for an active fault and the BF LED flags fieldbus trouble.

The fault buffer holds up to 8 active faults with the fault code in r0945, the fault number in r0947 and the fault value in r0949, the fault history keeps up to 56 older ones, and alarm codes sit in r2122 with alarm values in r2124.

Remove the cause first, then acknowledge from the operator panel, from a digital input wired to p2103 (for example p2103 = 722.1 for DI 1), with bit 7 of PROFIdrive control word 1, or by switching the power off and on, and note that faults from the internal hardware and firmware monitoring clear only with a power cycle.

Each fault has a default reaction: OFF1 brakes along the ramp-down time p1121, OFF2 removes the pulses at once so the motor coasts, and OFF3 brakes along the quick stop ramp p1135.

Where the List Manual shows other reactions in brackets the reaction can be changed with p2100 and p2101, the acknowledge mode with p2126 and p2127, and up to 20 messages can be turned from fault to alarm or suppressed with p2118 and p2119.

Safety first.
Siemens warns that the capacitors keep a hazardous voltage for up to 5 minutes after the power supply is switched off, and touching live parts can cause death or serious injury. Wait 5 minutes, then measure to confirm the unit really is free of voltage before you start work, and only open plug connections when the equipment is voltage free.

Siemens leaves the choice of remedy for each fault to qualified service and maintenance personnel, case by case. Follow lockout/tagout and your site's safe-work procedures, and check the manual for your exact model before you act.

Quick lookup

Most F faults run the drive's stop reaction (OFF1, OFF2 or OFF3), so in OEE they are availability losses; A alarms leave the motor running until you act, and a few faults have their reaction set to NONE.

Type a code or a word (overcurrent, PROFINET, motor blocked, overtemperature) to filter the list. F codes are faults, A codes are alarms; click a code for its causes and first checks.

67 codes

CodeTypeName
F01600FaultSI P1 (CU): STOP A initiated
F01611FaultSI P1 (CU): Defect in a monitoring channel
F01910FaultFieldbus interface setpoint timeout
A01920AlarmPROFIBUS: Interruption cyclic connection
F01018FaultBooting has been interrupted several times
A01590AlarmDrive: Motor maintenance interval expired
F03505FaultAnalog input wire breakage
A05000AlarmPower unit: Overtemperature heat sink AC inverter
A05006AlarmPower unit: Overtemperature thermal model
F06310FaultSupply voltage (p0210) incorrectly parameterized
F07011FaultDrive: Motor overtemperature
A07012AlarmDrive: Motor temperature model 1/3 overtemperature
A07015AlarmDrive: Motor temperature sensor alarm
F07016FaultDrive: Motor temperature sensor fault
F07320FaultDrive: Automatic restart interrupted
A07321AlarmDrive: Automatic restart active
F07330FaultFlying restart: Measured search current too low
A07400AlarmDrive: DC link voltage maximum controller active
F07404FaultDrive: DC link voltage monitoring Vdc_max
A07409AlarmDrive: U/f control, current limiting controller active
F07426FaultTechnology controller actual value limited
F07801FaultDrive: Motor overcurrent
F07802FaultDrive: Infeed or power unit not ready
A07805AlarmDrive: Power unit overload I2t
F07806FaultDrive: Regenerative power limit exceeded (F3E)
F07807FaultDrive: Short-circuit/ground fault detected
A07850AlarmExternal alarm 1
F07860FaultExternal fault 1
F07861FaultExternal fault 2
F07862FaultExternal fault 3
F07900FaultDrive: Motor blocked
F07901FaultDrive: Motor overspeed
F07902FaultDrive: Motor stalled
A07903AlarmDrive: Motor speed deviation
A07910AlarmDrive: Motor overtemperature
F07923FaultDrive: Torque/speed too low
A07927AlarmDC braking active
A07929AlarmDrive: No motor detected
A07991AlarmDrive: Motor data identification activated
F08501FaultPROFINET: Setpoint timeout
F08502FaultPROFINET: Monitoring time sign-of-life expired
A08511AlarmPROFINET: Receive configuration data invalid
A08526AlarmPROFINET: No cyclic connection
F30001FaultPower unit: Overcurrent
F30002FaultPower unit: DC link voltage overvoltage
F30003FaultPower unit: DC link voltage undervoltage
F30004FaultPower unit: Overtemperature heat sink AC inverter
F30005FaultPower unit: Overload I2t
F30011FaultPower unit: Line phase failure in main circuit
F30015FaultPower unit: Phase failure motor cable
A30016AlarmPower unit: Load supply switched off
F30017FaultPower unit: Hardware current limit has responded too often
F30021FaultPower unit: Ground fault
F30022FaultPower unit: Monitoring U_ce
F30024FaultPower unit: Overtemperature thermal model
F30025FaultPower unit: Chip overtemperature
F30027FaultPower unit: Precharging DC link time monitoring
F30035FaultPower unit: Air intake overtemperature
F30036FaultPower unit: Internal overtemperature
F30037FaultPower unit: Rectifier overtemperature
A30049AlarmPower unit: Internal fan faulty
F30059FaultPower unit: Internal fan faulty
A30502AlarmPower unit: DC link overvoltage
F30074FaultCommunication error between the Control Unit and Power Module
F31100FaultEncoder 1: Zero mark distance error
F31110FaultEncoder 1: Serial communications error
F31150FaultEncoder 1: Initialization error

Each code: causes and first checks

F01600: SI P1 (CU): STOP A initiated

Hits OEE: Availability

What it means: The built-in Safety Integrated function found an error and cut motor torque at once (STOP A). The motor coasts to a stop and cannot restart until the fault is cleared.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120 (CU320-2). Default reaction OFF2, acknowledge IMMEDIATELY (POWER ON).

Likely causes

  • The forced test stop of the safe switch-off path failed
  • Follow-up to F01611, a mismatch between the two safety monitoring channels
  • Pulses enabled or blocked in a way that does not match the STO selection
  • STO terminals on the Power Module switched on while that function is not enabled

First checks, in this order

  1. Read the fault value in r0949; value 9999 means work on F01611 first
  2. Select Safe Torque Off and deselect it again
  3. Power cycle all components
  4. Check the STO terminal wiring and the discrepancy time p9650/p9850
  5. Replace the Power Module if the fault keeps returning

F01611: SI P1 (CU): Defect in a monitoring channel

Hits OEE: Availability

What it means: The two safety channels inside the drive disagree when they cross-check their safety data, so the drive starts a safety stop. F01600 follows as a result.[1][2][3][4][5]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Default reaction NONE (adjustable to OFF1, OFF2, OFF3), acknowledge IMMEDIATELY (POWER ON).

Likely causes

  • Safety parameters differ between the two monitoring channels
  • Fail-safe input signal changing faster than the discrepancy time
  • STO selection or STO terminal state different in the two channels
  • Control Unit temperature outside the permitted range

First checks, in this order

  1. Read the fault value in r0949 and the cross-check number in r9795
  2. Check the fail-safe input wiring for loose or chattering contacts
  3. Check the discrepancy time p9650/p9850 and raise it if needed
  4. Power cycle the drive
  5. Contact Siemens support or replace the Control Unit if a firmware fault value stays

F01910: Fieldbus interface setpoint timeout

Hits OEE: Availability

What it means: The drive stopped receiving setpoints over the fieldbus (PROFIBUS, USS or Modbus) and stops the motor.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120 (G110M and S120 text: Fieldbus: setpoint timeout). Default reaction OFF3, acknowledge IMMEDIATELY.

Likely causes

  • Bus cable or connector interrupted
  • Communication partner switched off
  • PROFIBUS master set to STOP
  • Fieldbus monitoring time p2040 set too short

First checks, in this order

  1. Check the bus cable, plugs and termination
  2. Make sure the master or PLC is powered and in RUN
  3. Adapt the monitoring time p2040 if needed
  4. If it repeats on PROFIBUS, check the response monitoring set in the bus configuration (HW Config)

A01920: PROFIBUS: Interruption cyclic connection

Warning: act before it becomes a stop

What it means: The cyclic data link to the PROFIBUS master is down. The alarm clears itself when the link comes back.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Reaction NONE, no acknowledge needed.

Likely causes

  • PROFIBUS master not in cyclic operation
  • PROFIBUS cable or connector problem
  • Drive set to PROFIBUS but no master is used

First checks, in this order

  1. Restore the PROFIBUS connection and put the master in cyclic mode
  2. Check the bus cable and plugs
  3. If no fieldbus is used, set p2030 = 0 to suppress the message

F01018: Booting has been interrupted several times

Hits OEE: Availability

What it means: Start-up of the drive was interrupted several times in a row, so it boots with the factory settings.[1][2][3][4][6]

Also on: Same number on G120C, G110M and CU250S-2. Default reaction NONE, acknowledge POWER ON.

Likely causes

  • Power supply interrupted during start-up
  • Processor crash
  • Invalid parameter settings

First checks, in this order

  1. Power cycle the drive so it reboots from the valid settings if they exist
  2. Restore a valid parameter backup, for example from the memory card, and save it
  3. Recommission the drive if no valid backup exists

A01590: Drive: Motor maintenance interval expired

Warning: act before it becomes a stop

What it means: The service interval set for the motor has run out. It is a reminder, the motor keeps running.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Reaction NONE.

Likely causes

  • Motor operating hours reached the maintenance interval in p0651
  • Interval not reset after the last service

First checks, in this order

  1. Carry out the planned motor service
  2. Reset the maintenance interval p0651

F03505: Analog input wire breakage

Hits OEE: Availability

What it means: The wire break monitoring on an analog input tripped because the signal dropped below its threshold.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Default reaction OFF1 (adjustable to NONE, OFF2), acknowledge IMMEDIATELY (POWER ON).

Likely causes

  • Broken or loose wire to the signal source
  • Signal source delivering too little current
  • Analog input type set with monitoring while the signal can go low

First checks, in this order

  1. Check the wiring to the signal source for breaks
  2. Measure the injected signal and read the input current in r0752
  3. Check the analog input type and the threshold p0761

A05000: Power unit: Overtemperature heat sink AC inverter

Warning: act before it becomes a stop

What it means: The inverter heat sink is getting too hot. If it keeps rising past the fault threshold, the drive trips with F30004.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Reaction NONE.

Likely causes

  • Ambient temperature too high
  • Load or duty cycle too heavy for the drive
  • Cooling failed

First checks, in this order

  1. Check the cabinet and ambient temperature
  2. Check that the fan runs and the cooling path is clear
  3. Check the load and duty cycle
  4. Check the overload response set in p0290

A05006: Power unit: Overtemperature thermal model

Warning: act before it becomes a stop

What it means: The drive's thermal model sees too large a temperature difference between the power chips and the heat sink. If it keeps rising, F30024 follows.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Reaction NONE.

Likely causes

  • Load too high for the power unit
  • High pulse frequency or long operation at high current

First checks, in this order

  1. Watch whether the alarm clears by itself once the load drops
  2. Check the power unit temperatures in r0037
  3. Check the overload response in p0290

F06310: Supply voltage (p0210) incorrectly parameterized

Hits OEE: Availability

What it means: After precharging, the measured DC link voltage does not fit the supply voltage set in p0210.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Default reaction NONE (adjustable to OFF1, OFF2), acknowledge IMMEDIATELY (POWER ON).

Likely causes

  • Supply voltage p0210 set wrong for the plant
  • Actual line voltage out of tolerance

First checks, in this order

  1. Check p0210 against the real supply voltage and correct it
  2. Measure the line voltage
  3. Acknowledge with the drive switched off

F07011: Drive: Motor overtemperature

Hits OEE: Availability

What it means: The motor temperature sensor or the motor thermal model went past the fault threshold, so the drive stops the motor.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Default reaction OFF2 (adjustable to NONE, OFF1, OFF3, STOP2), acknowledge IMMEDIATELY.

Likely causes

  • Motor overloaded
  • Motor ambient temperature too high or poor ventilation
  • Temperature sensor wire broken or sensor not connected
  • Thermal model (I2t) temperature too high

First checks, in this order

  1. Reduce the motor load
  2. Check the ambient temperature and the motor fan
  3. Check the wiring of the PTC, KTY84, PT1000 or thermal switch
  4. Check the thresholds p0604, p0605 and the timer p0606

A07012: Drive: Motor temperature model 1/3 overtemperature

Warning: act before it becomes a stop

What it means: The drive's motor temperature model says the motor is running hot and has passed the alarm threshold. The motor keeps running for now.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Reaction NONE.

Likely causes

  • Motor load too high
  • Motor ambient temperature too high
  • Thermal time constant or model settings wrong

First checks, in this order

  1. Check the motor load and reduce it if needed
  2. Check the motor ambient temperature
  3. Check the model activation p0612 and the thermal time constant p0611
  4. Read the thermal motor utilization in r0034

A07015: Drive: Motor temperature sensor alarm

Warning: act before it becomes a stop

What it means: The drive cannot read the motor temperature sensor correctly. If the problem lasts longer than the timer p0607, it becomes fault F07016.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Reaction NONE.

Likely causes

  • Sensor wire broken or sensor not connected
  • Measured resistance too low, for example a short in the sensor cable
  • Wrong sensor type set in p0601

First checks, in this order

  1. Check the sensor cable and terminals
  2. Check the sensor type in p0601
  3. Read the motor temperature in r0035

F07016: Drive: Motor temperature sensor fault

Hits OEE: Availability

What it means: The motor temperature sensor fault from A07015 lasted too long, so the drive stops the motor.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Default reaction OFF1 (adjustable to NONE, OFF2, OFF3, STOP2), acknowledge IMMEDIATELY.

Likely causes

  • Sensor wire broken or sensor not connected
  • Measured resistance too low
  • Wrong sensor type set in p0601

First checks, in this order

  1. Check the sensor connection
  2. Check the sensor type in p0601
  3. For induction motors without a sensor, the sensor fault can be turned off with p0607 = 0

F07320: Drive: Automatic restart interrupted

Hits OEE: Availability

What it means: The automatic restart function gave up because it used all its restart attempts or a monitoring time ran out.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Default reaction OFF2, acknowledge IMMEDIATELY.

Likely causes

  • All restart attempts p1211 used without the faults clearing within the monitoring time p1213
  • Power unit monitoring time p0857 expired
  • Drive not switched on again after commissioning or motor identification

First checks, in this order

  1. Find and fix the fault that started the restarts
  2. Switch the motor off (OFF1) and acknowledge the fault
  3. Check the restart attempts p1211 and the actual count in r1214
  4. Check the wait time p1212, the monitoring time p1213 and p0857

A07321: Drive: Automatic restart active

Warning: act before it becomes a stop

What it means: Automatic restart is armed. When the supply returns or the fault causes are gone, the drive restarts the motor by itself.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Reaction NONE.

Likely causes

  • Line supply returned after a power failure with automatic restart p1210 enabled
  • Fault causes removed while automatic restart is set to restart the drive

First checks, in this order

  1. Keep people clear of the machine, it can start on its own
  2. Withdraw the ON command (p0840) to stop the restart
  3. Turn automatic restart off with p1210 = 0 if it is not wanted

F07330: Flying restart: Measured search current too low

Hits OEE: Availability

What it means: During a flying restart onto a spinning motor, the search current stayed too low. The motor may not be connected.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120 (vector). Default reaction OFF2 (adjustable to NONE, OFF1), acknowledge IMMEDIATELY.

Likely causes

  • Motor cable disconnected or open
  • Search current set too low

First checks, in this order

  1. Check the motor cables and motor terminals
  2. Increase the search current p1202

A07400: Drive: DC link voltage maximum controller active

Warning: act before it becomes a stop

What it means: The DC link voltage climbed while braking, so the drive is stretching the ramp-down time on its own to avoid an overvoltage trip.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Reaction NONE.

Likely causes

  • Ramp-down time too short for the load inertia
  • Load driving the motor (regenerating) with no braking resistor or regenerative unit

First checks, in this order

  1. Increase the ramp-down time p1121
  2. Use a braking chopper or a regenerative unit if the ramp time must stay
  3. Only if the controller must not act: switch it off (p1240 = 0 vector, p1280 = 0 V/f)

F07404: Drive: DC link voltage monitoring Vdc_max

Hits OEE: Availability

What it means: In V/f control, the DC link voltage monitor p1284 tripped because the voltage went too high.[1][2][3][4][5]

Also on: Same number on G120C, G110M and CU250S-2. S120 uses F07404 with the text Upper DC link voltage threshold reached. Default reaction OFF2 (adjustable to NONE, OFF1, OFF3), acknowledge IMMEDIATELY.

Likely causes

  • Line voltage too high
  • Braking module problem
  • Supply voltage p0210 or monitoring threshold p1284 set wrong

First checks, in this order

  1. Measure the line voltage
  2. Check the braking module
  3. Check p0210 and the monitoring setting p1284

A07409: Drive: U/f control, current limiting controller active

Warning: act before it becomes a stop

What it means: In V/f mode the motor current hit the current limit, so the drive is holding back speed to keep the current down.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120 (vector). Reaction NONE.

Likely causes

  • Load too high
  • Ramp-up too fast
  • Current limit p0640 set too low

First checks, in this order

  1. Reduce the load or check for mechanical binding
  2. Make the ramp-up to the setpoint slower (p1120)
  3. Raise the current limit p0640 if the motor and drive allow it

F07426: Technology controller actual value limited

Hits OEE: Availability

What it means: The feedback signal of the built-in PID (technology) controller reached its upper or lower limit.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Default reaction OFF1 (adjustable), acknowledge IMMEDIATELY.

Likely causes

  • Feedback sensor signal out of range or failed
  • Limits p2267 or p2268 not matched to the sensor signal
  • Wrong scaling of the actual value

First checks, in this order

  1. Read the fault value: 1 upper limit, 2 lower limit
  2. Check the feedback sensor and its wiring
  3. Match the limits p2267 and p2268 to the signal level
  4. Check the scaling p0595 and p0596

F07801: Drive: Motor overcurrent

Hits OEE: Availability

What it means: The motor current went past the permitted motor limit current and the drive stopped the motor.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Default reaction OFF2 (adjustable to NONE, OFF1, OFF3), acknowledge IMMEDIATELY.

Likely causes

  • Current limit set too low or current controller badly tuned
  • V/f mode: ramp-up too short or load too high
  • V/f mode: short circuit or ground fault in the motor cable
  • Motor current does not suit the power unit
  • Start onto a spinning motor without flying restart (p1200)

First checks, in this order

  1. Check the motor and motor cable for short circuits and ground faults
  2. Check the star or delta connection against the rating plate data entered
  3. Check the current limit p0640 and the ramp-up time p1120, or reduce the load
  4. Check the power unit and motor combination
  5. Enable flying restart p1200 if the motor can be spinning at start

F07802: Drive: Infeed or power unit not ready

Hits OEE: Availability

What it means: After the switch-on command, the power unit did not report ready in time.[1][2][3][4][5]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Default reaction OFF2 (adjustable to NONE), acknowledge IMMEDIATELY.

Likely causes

  • Power unit monitoring time too short
  • No DC link voltage
  • Power unit defective
  • Supply voltage set wrong

First checks, in this order

  1. Check that the line supply is on and the DC link has voltage
  2. Check the supply voltage setting p0210
  3. Increase the monitoring time p0857
  4. Replace the power unit if it still does not report ready

A07805: Drive: Power unit overload I2t

Warning: act before it becomes a stop

What it means: The power unit is overloaded and passed its I2t alarm threshold. The response set in p0290, such as cutting current, kicks in.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Reaction NONE.

Likely causes

  • Continuous load too high
  • Duty cycle too heavy
  • Motor and power unit rated currents do not match

First checks, in this order

  1. Reduce the continuous load
  2. Adapt the duty cycle
  3. Check the motor and power unit rated currents
  4. Check the overload response p0290

F07806: Drive: Regenerative power limit exceeded (F3E)

Hits OEE: Availability

What it means: On regenerative PM250 or PM260 power units, the power fed back to the line stayed above the rated regenerative power for too long.[1][3][6]

Also on: Same number on CU250S-2. Siemens describes it for PM250 and PM260 power units. Default reaction OFF2, acknowledge IMMEDIATELY.

Likely causes

  • Ramp-down too fast
  • Load driving the motor too hard
  • Power unit too small for the energy fed back

First checks, in this order

  1. Increase the ramp-down time
  2. Reduce the driving load
  3. In vector control, lower the regenerative power limit p1531
  4. Use a power unit with more regenerative capacity

F07807: Drive: Short-circuit/ground fault detected

Hits OEE: Availability

What it means: The drive found a phase to phase short circuit or a ground fault at its motor output terminals.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120 (vector). Default reaction OFF2 (adjustable to NONE), acknowledge IMMEDIATELY.

Likely causes

  • Short circuit between motor phases in the cable or motor
  • Ground fault in the motor or motor cable
  • Line and motor cables swapped at the drive
  • Switching onto a motor that is still turning or not fully de-energized

First checks, in this order

  1. Read r0949: 1 to 3 show the shorted phase pair, 4 a ground fault, 5 to 7 an open motor phase
  2. Check the motor cable and motor for shorts and ground faults
  3. Confirm line and motor cables are not swapped
  4. If starting onto a spinning motor, enable flying restart p1200 or increase p0347 and p1228

A07850: External alarm 1

Warning: act before it becomes a stop

What it means: A warning signal from outside the drive, wired to the drive and selected in p2112, is active. The motor keeps running.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Reaction NONE.

Likely causes

  • The external device or contact wired to p2112 signalled an alarm
  • Wire break on that input (the alarm reacts to a 1 to 0 change)

First checks, in this order

  1. Check which signal is assigned in p2112
  2. Check the external device and its wiring
  3. Fix the external cause, the alarm then clears itself

F07860: External fault 1

Hits OEE: Availability

What it means: A stop signal from outside the drive, wired to the input selected in p2106, has tripped the drive. The problem is in the external device, not in the drive.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Default reaction OFF2 (adjustable), acknowledge IMMEDIATELY (POWER ON).

Likely causes

  • External device (thermal switch, interlock, safety relay or PLC) signalled a fault
  • Wire break or loose terminal on the input set in p2106 (it reacts to a 1 to 0 change)

First checks, in this order

  1. Check which signal is assigned in p2106
  2. Check the external device that feeds that input
  3. Check the wiring and terminal for a break
  4. Fix the external cause, then acknowledge

F07861: External fault 2

Hits OEE: Availability

What it means: A second external stop signal, wired to the input selected in p2107, has tripped the drive.[1][3][4][5][6]

Also on: Same number on G110M, CU250S-2 and S120. Default reaction OFF2 (adjustable), acknowledge IMMEDIATELY (POWER ON).

Likely causes

  • External device wired to p2107 signalled a fault
  • Wire break on that input

First checks, in this order

  1. Check which signal is assigned in p2107
  2. Check the external device and wiring
  3. Fix the external cause, then acknowledge

F07862: External fault 3

Hits OEE: Availability

What it means: A third external stop signal has tripped the drive. It is built from p2108 combined with the enables p3111 and p3112 and the delay p3110.[1][3][4][5][6]

Also on: Same number on G110M, CU250S-2 and S120. Default reaction OFF2 (adjustable), acknowledge IMMEDIATELY (POWER ON).

Likely causes

  • External device wired to p2108 signalled a fault
  • Enable signal p3111 or p3112 in an unexpected state
  • Wire break on the input

First checks, in this order

  1. Check the signals in p2108, p3111 and p3112
  2. Check the external device and wiring
  3. Fix the external cause, then acknowledge

F07900: Drive: Motor blocked

Hits OEE: Availability

What it means: The motor sat at its torque limit at low speed for longer than allowed, so the drive decided it is blocked and stopped it.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120 (S120 servo text: Motor blocked/speed controller at its limit). Default reaction OFF2 (adjustable to NONE, OFF1, OFF3, STOP2), acknowledge IMMEDIATELY.

Likely causes

  • Mechanical jam or load too heavy for the torque limit
  • Speed oscillating so the speed controller keeps hitting its limit
  • Power unit thermal protection lowering the current limit (p0290)
  • Motor blocked thresholds p2175 or p2177 set too tight

First checks, in this order

  1. Check that the motor and machine can turn freely
  2. Check the effective torque limits r1538 and r1539
  3. Check the motor blocked settings p2175 and p2177
  4. In V/f mode, check the current limit p0640 and ramp-up time p1120

F07901: Drive: Motor overspeed

Hits OEE: Availability

What it means: The motor ran faster than the maximum speed allowed in either direction.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Default reaction OFF2, acknowledge IMMEDIATELY.

Likely causes

  • Load pulling the motor faster than the setpoint
  • Maximum speed p1082 or hysteresis p2162 set too low

First checks, in this order

  1. Check the maximum speed p1082 against r1084 and r1087
  2. Raise the overspeed hysteresis p2162 if needed
  3. Activate the speed limiting controller precontrol (p1401.7 = 1)

F07902: Drive: Motor stalled

Hits OEE: Availability

What it means: The control decided the motor has stalled (lost control of the rotor) for longer than the time in p2178.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Default reaction OFF2 (adjustable), acknowledge IMMEDIATELY.

Likely causes

  • Motor data wrong or motor identification not done
  • Load too heavy at low speed or ramps too short
  • Current limits too low to magnetize the motor
  • Motor cable disconnected or a line phase missing

First checks, in this order

  1. Check the motor data and run the motor data identification (p1900)
  2. Increase the ramp times p1120 and p1121
  3. Check the current limits p0640, r0067 and r0289
  4. Check the motor cables and line phases
  5. Only if all is fine, raise the tolerance p1745 or the delay p2178

A07903: Drive: Motor speed deviation

Warning: act before it becomes a stop

What it means: The actual speed stayed away from the setpoint by more than the tolerance for too long.[1][3][4][5][6]

Also on: Same number on G110M, CU250S-2 and S120. Reaction NONE.

Likely causes

  • Load torque higher than the drive can deliver
  • Torque, current or power limit reached while accelerating
  • Drive sized too small

First checks, in this order

  1. Check the load and the torque, current and power limits
  2. Raise the tolerance p2163 or the time p2166 if the process allows
  3. Turn the alarm off with p2149.0 = 0 if it is not needed

A07910: Drive: Motor overtemperature

Warning: act before it becomes a stop

What it means: The measured motor temperature, or the motor thermal model, passed the alarm threshold p0604. The response set in p0610 applies, for example reducing output current.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Reaction NONE.

Likely causes

  • Motor overloaded
  • Motor ambient temperature too high
  • PTC tripped or thermal switch opened

First checks, in this order

  1. Check the motor load
  2. Check the motor ambient temperature and ventilation
  3. Check the KTY84 or PT1000 sensor
  4. Check the model limits p0626 to p0628

F07923: Drive: Torque/speed too low

Hits OEE: Availability

What it means: Load monitoring found the torque, or the external speed signal, below the expected envelope. It points to a lost connection to the load, such as a broken belt.[1][3][4][5][6]

Also on: Same number on G110M, CU250S-2 and S120. Default reaction OFF1 (adjustable to NONE, OFF2, OFF3), acknowledge IMMEDIATELY.

Likely causes

  • Broken belt or coupling between motor and load
  • Load missing or much lighter than expected
  • Load monitoring envelope set wrong

First checks, in this order

  1. Check the connection between motor and load (belt, coupling)
  2. Check the load monitoring mode p2193 and the envelope settings
  3. Adapt the settings to the real load

A07927: DC braking active

Warning: act before it becomes a stop

What it means: The motor is being braked with DC current. This is a status message, not a defect.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Reaction NONE.

Likely causes

  • A fault with reaction DC braking is active
  • DC braking selected on purpose via p1230

First checks, in this order

  1. No action needed, the alarm clears when DC braking ends
  2. If it was not expected, check the fault buffer for the fault that started it

A07929: Drive: No motor detected

Warning: act before it becomes a stop

What it means: After the output was switched on, the current was so small that the drive could not find a motor. In vector control with an induction motor, F07902 follows.[1][2][3][4]

Also on: Same number on G120C, G110M and CU250S-2. Reaction NONE.

Likely causes

  • Motor cable disconnected or open
  • V/f voltage boost too low

First checks, in this order

  1. Check the motor feeder cables
  2. Check the V/f voltage boost p1310
  3. Run a standstill measurement to set the stator resistance (p0350)

A07991: Drive: Motor data identification activated

Warning: act before it becomes a stop

What it means: Motor data identification is armed and runs at the next ON command. Parameters cannot be saved while a rotating measurement is pending.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Reaction NONE.

Likely causes

  • Motor identification selected during commissioning (p1900 or p1910)
  • No ON command given yet since the identification was selected

First checks, in this order

  1. Switch the motor on to run the identification
  2. Or cancel it with p1900 = 0 if it is not wanted

F08501: PROFINET: Setpoint timeout

Hits OEE: Availability

What it means: The drive stopped getting setpoints from the PLC over PROFINET, so it stops the motor.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120 (S120 text: PN/COMM BOARD: Setpoint timeout). Default reaction OFF3 (adjustable), acknowledge IMMEDIATELY.

Likely causes

  • PROFINET cable or switch interrupted
  • PLC switched off
  • PLC set to STOP

First checks, in this order

  1. Check the PROFINET cable, ports and switches
  2. Put the PLC back in RUN
  3. Acknowledge the fault once the link is back
  4. If it repeats, check the update and monitoring time in the bus configuration

F08502: PROFINET: Monitoring time sign-of-life expired

Hits OEE: Availability

What it means: The sign-of-life counter from the PLC stopped updating in time, so the drive treats the PROFINET link as lost.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Default reaction OFF1 (adjustable to OFF2, OFF3), acknowledge IMMEDIATELY.

Likely causes

  • PROFINET connection interrupted
  • PLC no longer sending the sign-of-life

First checks, in this order

  1. Check the PROFINET connection
  2. Power cycle the drive
  3. Contact Siemens Technical Support if it continues

A08511: PROFINET: Receive configuration data invalid

Warning: act before it becomes a stop

What it means: The drive rejected the configuration the PLC sent, so cyclic data exchange cannot start.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Reaction NONE.

Likely causes

  • Too many process data words in the configured telegram
  • Odd number of bytes for input or output
  • PROFIsafe address or telegram mismatch

First checks, in this order

  1. Read the alarm value in r2124
  2. Check the telegram and data word count in the PLC hardware configuration
  3. For PROFIsafe, check the address p9610

A08526: PROFINET: No cyclic connection

Warning: act before it becomes a stop

What it means: The drive has no cyclic link to a PROFINET controller. It clears itself once the PLC connects.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Reaction NONE.

Likely causes

  • PLC not running cyclic operation
  • Device name or IP address does not match the PLC project
  • Cable or network problem

First checks, in this order

  1. Check that the PLC is in RUN with cyclic operation
  2. Check the station name and IP address in r61000 and r61001 against the PLC project
  3. Check the PROFINET cable and switch ports

F30001: Power unit: Overcurrent

Hits OEE: Availability

What it means: The power unit hardware measured an overcurrent and shut the output off at once to protect itself.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Default reaction OFF2, acknowledge IMMEDIATELY.

Likely causes

  • Short circuit or ground fault in the motor or motor cable
  • Control parameters wrong or V/f ramp-up too short
  • Motor rated current much larger than the power unit
  • Missing line reactor, power cables too long or badly connected
  • Line phase interrupted or power unit defective

First checks, in this order

  1. Read r0949: bits 0 to 2 show phase U, V or W, bit 3 the DC link
  2. Check the motor cable and motor for short circuits and ground faults
  3. Check the motor data and star or delta connection
  4. In V/f mode, increase the ramp-up time and reduce the load
  5. Check the power cable length and line reactor, then replace the power unit if the fault stays

F30002: Power unit: DC link voltage overvoltage

Hits OEE: Availability

What it means: The DC link voltage rose too high, usually because the motor fed energy back while braking.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Default reaction OFF2, acknowledge IMMEDIATELY.

Likely causes

  • Motor regenerating too much energy (fast stop or overhauling load)
  • Line voltage too high
  • DC link voltage controller off or badly tuned
  • Line phase interrupted

First checks, in this order

  1. Increase the ramp-down time p1121 and set rounding times p1130, p1136
  2. Activate the DC link voltage controller (p1240, p1280)
  3. Check the line voltage and p0210
  4. Check the line phases and the phase assignment at the power unit

F30003: Power unit: DC link voltage undervoltage

Hits OEE: Availability

What it means: The DC link voltage dropped too low, so the drive stops the motor.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Default reaction OFF2, acknowledge IMMEDIATELY.

Likely causes

  • Line supply failure or dip
  • Line voltage below the permitted value
  • Line phase interrupted

First checks, in this order

  1. Measure the line voltage at the drive input
  2. Check the line phases and input fuses
  3. Check the supply voltage setting p0210

F30004: Power unit: Overtemperature heat sink AC inverter

Hits OEE: Availability

What it means: The heat sink of the power unit went past its temperature limit and the drive tripped.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Default reaction OFF2, acknowledge IMMEDIATELY.

Likely causes

  • Fan failed or cooling blocked
  • Overload
  • Ambient temperature too high
  • Pulse frequency too high

First checks, in this order

  1. Check that the fan runs and check the fan elements
  2. Check the cabinet and ambient temperature
  3. Check the motor load
  4. Reduce the pulse frequency p1800 if it is above the rated value
  5. Let it cool, it can only be acknowledged once below the A05000 threshold

F30005: Power unit: Overload I2t

Hits OEE: Availability

What it means: The power unit carried more than its rated current for too long and its I2t overload model reached full scale.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Default reaction OFF2, acknowledge IMMEDIATELY.

Likely causes

  • Rated power unit current exceeded for too long
  • Duty cycle not respected

First checks, in this order

  1. Reduce the continuous load or adapt the duty cycle
  2. Check the motor and power unit rated currents
  3. Reduce the current limit p0640
  4. In V/f mode, reduce p1341

F30011: Power unit: Line phase failure in main circuit

Hits OEE: Availability

What it means: The ripple on the DC link got too large, which points to a missing or unbalanced line phase.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Default reaction OFF2 (adjustable to OFF1), acknowledge IMMEDIATELY.

Likely causes

  • Line phase lost or fuse blown
  • Line phases badly unbalanced
  • Resonance between DC link and line inductance
  • Motor phase failed

First checks, in this order

  1. Check the main circuit fuses
  2. Measure all three line phases
  3. Check for single phase loads distorting the line
  4. Check the motor cables

F30015: Power unit: Phase failure motor cable

Hits OEE: Availability

What it means: The drive detected a missing phase in the motor cable.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Default reaction OFF2 (adjustable), acknowledge IMMEDIATELY.

Likely causes

  • Open motor phase in the cable, terminal or motor
  • Motor stalled in V/f mode giving unbalanced currents
  • Unstable speed control causing torque oscillation

First checks, in this order

  1. Check the motor cable and terminals on all three phases
  2. In V/f mode, increase the ramp times if the motor stalls
  3. Check the speed controller settings

A30016: Power unit: Load supply switched off

Warning: act before it becomes a stop

What it means: The DC link voltage is too low because the main supply is not on.[1][2][3][4][5]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Reaction NONE.

Likely causes

  • AC line supply to the power unit not switched on
  • DC link voltage too low

First checks, in this order

  1. Check the line contactor or main switch
  2. Measure the line voltage at the power unit

F30017: Power unit: Hardware current limit has responded too often

Hits OEE: Availability

What it means: The fast hardware current limit in one or more phases kicked in too many times.[1][2][3][4][5]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Default reaction OFF2, acknowledge IMMEDIATELY.

Likely causes

  • Control parameters wrong
  • Fault in the motor or power cables
  • Power cables too long
  • Motor load too high or power unit defective

First checks, in this order

  1. Read r0949 to see phase U, V or W
  2. Check the motor data and star or delta connection
  3. Check the motor load and power cables for shorts or ground faults
  4. Check the power cable length

F30021: Power unit: Ground fault

Hits OEE: Availability

What it means: The power unit detected current flowing to ground (earth).[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Default reaction OFF2, acknowledge IMMEDIATELY.

Likely causes

  • Ground fault in the power cables
  • Ground fault in the motor
  • Current transformer defective
  • Brake connection wiring fault or braking resistor short

First checks, in this order

  1. Check the power cable connections
  2. Check the motor and motor cable for a ground fault
  3. Check the brake cable and contacts
  4. Check the braking resistor

F30022: Power unit: Monitoring U_ce

Hits OEE: Availability

What it means: The monitoring of the IGBT collector emitter voltage in the power unit tripped. Siemens treats it as a hardware fault that needs a power cycle.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Default reaction OFF2, acknowledge POWER ON.

Likely causes

  • Short circuit at the power unit output
  • Defective semiconductor in the power unit
  • Gate drive supply or signal fault

First checks, in this order

  1. Check the power cable connections and motor cable for shorts
  2. Power cycle the drive
  3. Check or replace the Power Module if it returns

F30024: Power unit: Overtemperature thermal model

Hits OEE: Availability

What it means: The thermal model says the temperature difference between the power chips and the heat sink is too large, so the drive trips. A05006 usually comes first.[1][2][3][4][5]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Default reaction OFF2, acknowledge IMMEDIATELY.

Likely causes

  • Duty cycle not respected
  • Fan failed or cooling poor
  • Overload or high ambient temperature
  • Pulse frequency too high

First checks, in this order

  1. Adapt the load duty cycle
  2. Check that the fan runs and check the fan elements
  3. Check the ambient temperature and motor load
  4. Reduce the pulse frequency, and if DC braking is used, reduce the braking current p1232

F30025: Power unit: Chip overtemperature

Hits OEE: Availability

What it means: The semiconductor chip temperature in the power unit went past its limit.[1][2][3][4][5]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Default reaction OFF2, acknowledge IMMEDIATELY.

Likely causes

  • Duty cycle not respected
  • Fan failed or cooling poor
  • Overload or high ambient temperature
  • Pulse frequency too high

First checks, in this order

  1. Adapt the load duty cycle
  2. Check the fan and cooling path
  3. Check the ambient temperature and motor load
  4. Reduce the pulse frequency if above rated, then acknowledge once below the A05001 threshold

F30027: Power unit: Precharging DC link time monitoring

Hits OEE: Availability

What it means: The DC link could not charge up within the expected time after power was applied.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Default reaction OFF2, acknowledge IMMEDIATELY.

Likely causes

  • No line voltage or line contactor not closed
  • Line voltage too low or p0210 set wrong
  • Precharge resistors overheated from too many power-ups
  • Ground fault or short circuit on the DC link

First checks, in this order

  1. Measure the line voltage at the input terminals
  2. Check the supply voltage setting p0210
  3. Wait for the precharge resistors to cool and limit frequent power cycling
  4. Check the DC link for a ground fault or short

F30035: Power unit: Air intake overtemperature

Hits OEE: Availability

What it means: The cooling air entering the power unit is too hot.[1][2][4][5][6]

Also on: Same number on G120C, G110M and S120. Default reaction OFF1 (adjustable to OFF2), acknowledge IMMEDIATELY.

Likely causes

  • Ambient or cabinet temperature too high
  • Fan failed or cooling blocked

First checks, in this order

  1. Check that the fan runs
  2. Check the fan elements and filters
  3. Check the cabinet and ambient temperature
  4. Acknowledge once below the A05002 alarm threshold

F30036: Power unit: Internal overtemperature

Hits OEE: Availability

What it means: The temperature inside the drive went past its limit.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Default reaction OFF2, acknowledge IMMEDIATELY.

Likely causes

  • Fan failed or cooling poor
  • Overload
  • Ambient temperature too high

First checks, in this order

  1. Check that the fan runs
  2. Check the fan elements
  3. Check the ambient temperature, then let the drive cool before acknowledging

F30037: Power unit: Rectifier overtemperature

Hits OEE: Availability

What it means: The rectifier (input stage) of the power unit is too hot.[1][2][4][5][6]

Also on: Same number on G120C, G110M and S120. Default reaction OFF2, acknowledge IMMEDIATELY.

Likely causes

  • Fan failed or cooling poor
  • Overload
  • Ambient temperature too high
  • Line phase failure

First checks, in this order

  1. Check that the fan runs and the fan elements are clean
  2. Check the ambient temperature and motor load
  3. Check the line phases
  4. Acknowledge once below the A05004 alarm threshold

A30049: Power unit: Internal fan faulty

Warning: act before it becomes a stop

What it means: The internal fan of the power unit has failed. The drive keeps running for now but cooling is reduced.[1][2][4][5][6]

Also on: Same number on G120C, G110M and S120. Reaction NONE.

Likely causes

  • Internal fan has failed
  • Fan possibly defective and due for replacement

First checks, in this order

  1. Check the internal fan
  2. Replace the fan if needed

F30059: Power unit: Internal fan faulty

Hits OEE: Availability

What it means: The internal fan of the power unit has failed and may be defective, so the drive trips.[1][2][4][5][6]

Also on: Same number on G120C, G110M and S120. Default reaction OFF2, acknowledge IMMEDIATELY.

Likely causes

  • Internal power unit fan has failed
  • Fan possibly defective

First checks, in this order

  1. Check the internal fan
  2. Replace the fan if needed

A30502: Power unit: DC link overvoltage

Warning: act before it becomes a stop

What it means: With the output off, the power unit sees too high a DC link voltage.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Reaction NONE.

Likely causes

  • Supply voltage too high
  • Line reactor sized wrong

First checks, in this order

  1. Check the supply voltage and p0210
  2. Check the line reactor sizing
  3. Read the DC link voltage in r0070

F30074: Communication error between the Control Unit and Power Module

Hits OEE: Availability

What it means: The Control Unit lost contact with the Power Module it plugs onto.[1][2][3][4][5][6]

Also on: Same number on G120C, G110M, CU250S-2 and S120. Default reaction NONE, acknowledge IMMEDIATELY.

Likely causes

  • Control Unit pulled off or badly seated on the Power Module
  • External 24 V to the Control Unit interrupted while the Power Module was off
  • Control Unit fitted to a different Power Module

First checks, in this order

  1. Read the fault value in r0949
  2. Seat the Control Unit firmly on the right Power Module
  3. Power cycle the Control Unit

F31100: Encoder 1: Zero mark distance error

Hits OEE: Availability

What it means: On a CU250S-2 with an encoder, the measured distance between zero marks does not match the set value.[3][5]

Also on: CU250S-2 (encoder operation) and S120 use the same number. Default reaction ENCODER (adjustable), acknowledge PULSE INHIBIT.

Likely causes

  • Electrical noise on the encoder cable
  • Loose encoder plug
  • Wrong encoder type or zero mark distance setting
  • Encoder or encoder cable defective

First checks, in this order

  1. Check the encoder cable routing and shield for EMC
  2. Check the plug connections
  3. Check the encoder type and the zero mark distance p0424 or p0425
  4. Replace the encoder or cable if it continues

F31110: Encoder 1: Serial communications error

Hits OEE: Availability

What it means: The serial data link between an absolute encoder and the drive has errors.[3][5]

Also on: CU250S-2 and S120 use the same number. Default reaction ENCODER (adjustable to NONE), acknowledge PULSE INHIBIT.

Likely causes

  • Wrong encoder type set
  • Electrical noise or missing cable shield
  • Encoder or encoder cable defective
  • Parameter setting for the protocol wrong

First checks, in this order

  1. Read the fault value bits in r0949
  2. Check the cable shield connection and routing
  3. Check the encoder type settings
  4. Replace the encoder or encoder cable

F31150: Encoder 1: Initialization error

Hits OEE: Availability

What it means: The encoder functions selected in the drive do not work as set up.[3][5]

Also on: CU250S-2 and S120 use the same number. Default reaction ENCODER (adjustable), acknowledge PULSE INHIBIT.

Likely causes

  • Encoder configuration p0404 set wrong
  • Wrong encoder type (incremental or absolute)
  • Encoder cable problem

First checks, in this order

  1. Check that p0404 is set correctly
  2. Check the encoder type and the encoder cable
  3. Look for other encoder faults that give more detail

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, and count the alarms that repeat before they become faults.

  • Reason code: the code plus the drive, for example G120 F08501, filler infeed drive, so a PROFINET timeout that trips at every shift start 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 F30001 to F30004 and the other common SINAMICS power faults, fabrico.io has the SINAMICS drive 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 read the fault history on a SINAMICS G120?

Open r0945 for the fault codes and r0949 for the fault values; index 0 to 7 hold the current faults and higher indexes hold older, acknowledged ones. The fault times are in r0948 and r2130, and p0952 counts the fault cases. Alarm codes are in r2122 and alarm values in r2124, and setting p0952 = 0 clears the fault history.

What is the difference between an F code and an A code on a G120?

An F code is a fault: the drive runs its stop reaction, usually OFF1, OFF2 or OFF3, and you must fix the cause and acknowledge it. An A code is an alarm: the motor keeps running and the message clears itself when the cause goes away. Some alarms warn that a fault is close, for example A05000 before F30004.

How do I acknowledge F08501 after the PLC comes back?

First restore the PROFINET link and put the PLC in RUN, because the acknowledge has no effect while the cause is still there. Then acknowledge with a 0 to 1 edge on bit 7 of control word 1 from the PLC, from the operator panel, or from a digital input wired to p2103. If F08501 keeps coming back, Siemens says to check the update time set in the bus configuration.

Why does a fault come straight back after I acknowledge it?

Siemens states that the fault stays displayed if the cause has not been removed. Some faults also have limits: faults marked POWER ON need a power cycle, and heat faults like F30004 can only be acknowledged once the temperature drops below the matching alarm threshold. Check the cause in the List Manual entry and the fault value in r0949 before trying again.

What is the difference between F07801 and F30001?

F07801 Motor overcurrent comes from the drive control and compares the motor current with the motor limit current, and its reaction can be changed. F30001 Power unit overcurrent is detected by the power unit hardware itself and always uses OFF2. For F30001 the bits in r0949 show which phase, U, V or W, or the DC link saw the overcurrent.

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. SINAMICS G120 Control Units CU240B-2/CU240E-2 List Manual, Edition 09/2020, A5E33839529, firmware 4.7 SP13 (chapter 4 Faults and alarms)
  2. SINAMICS G120C List Manual, Edition 02/2023, A5E33840768, firmware 4.7 SP14 (chapter 4 Faults and alarms)
  3. SINAMICS G120 CU250S-2 Control Units List Manual, Edition 09/2020, A5E33842890, firmware 4.7 SP13 (chapter 4 Faults and alarms)
  4. SINAMICS G110M List Manual, Edition 09/2020, A5E33843470, firmware 4.7 SP13 (chapter 4 Faults and alarms)
  5. SINAMICS S120/S150 List Manual, Edition 07/2018, 6SL3097-5AP00-0BP0, firmware 5.1 SP1 (chapter 4 Faults and alarms)
  6. SINAMICS G120 Converter with the CU240B-2 and CU240E-2 Control Units, Operating Instructions, Edition 04/2018, firmware V4.7 SP10, A5E34259001B AF (chapter 8 Alarms, faults and system messages)

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: Siemens MICROMASTER 440 fault codes · Siemens MASTERDRIVES fault codes · VFD drive troubleshooting · electric motor

Other alarm code lookups: FANUC: servo amplifier · spindle amplifier · robot SRVO | Siemens: MICROMASTER 440 · MASTERDRIVES · SINAMICS V90 servo · SINAMICS V20 | ABB: ACS550 drive · ACS800 drive · robot IRC5 | Okuma: OSP alarms | Haas: alarm lookup | Mitsubishi: MELSERVO servo · FR-D700 and FR-E700 inverters · FX PLC | Allen-Bradley: Kinetix and Ultra3000 · MicroLogix · PowerFlex 753 and 755 · PowerFlex 70 and 700 · 1336 and 1305 | Yaskawa: V1000 drive · SERVOPACK servo · Motoman robot | Delta: VFD drives · ASDA servo | Eaton: DC1 and SVX9000 drives | Control Techniques: Commander SK and M200 | Kollmorgen: AKD servo | Lenze: SMVector, 8200, 8400, i500 | Magnetek: IMPULSE and DSD 412 | Omron: MX2 and RX inverters · G5 and 1S servo | WEG: CFW500, CFW300, CFW11, CFW08 | Hitachi: WJ200 inverter | Toshiba: E3, Q9, P9, S15, nC3, AS3 | AutomationDirect: GS10, GS20, GS4, GS1 to GS3 | SANYO DENKI: SANMOTION servo | Parker: SSD 590+, 690+, AC10 | KEB: COMBIVERT F5 | Epson: robot RC700, RC90 | B&R: ACOPOS servo | Schneider Electric: Lexium 32 servo | Bosch Rexroth: IndraDrive | Vacon: NX, VACON 100 and 20 | Fuji Electric: FRENIC-Mini, Multi, Ace, MEGA | LS Electric: S100, G100, iG5A | Panasonic: MINAS A6 and A5 servo | Invertek: Optidrive E3, P2, Eco | SEW-Eurodrive: MOVITRAC B and MOVIDRIVE B

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