ABB DCS800 Fault Codes

F502: ArmOverCur (Armature overcurrent)

What it means: Armature current went above the converter's own overcurrent level, ConvOvrCur (4.16), or above the level set in ArmOvrCurLev (30.09), so the drive tripped.^[1][2][3]

Also on: DCS550 (same code and name; its check list asks to confirm TypeCode (97.01))

Drive response: Trip level 3, monitored always: main contactor opens at once, fan keeps running, stop handled by SpeedFbFltMode (30.36)

Likely causes

• Armature current controller badly tuned (group 43)
• Current or torque limits in group 20 set too high
• Synchronizing voltage out of phase with the mains (sync transformer or separate 230 V / 115 V network)
• Failed thyristor or a fault in the armature cabling
• Rebuild kit: firing pulse or current transformer wiring wrong, or S ConvScaleCur (97.02) set wrong

First checks, in this order

1. Compare ArmOvrCurLev (30.09) with the converter level shown in ConvOvrCur (4.16).
2. Check the armature current controller settings in group 43 and repeat the armature current autotuning if needed.
3. Check the current and torque limits in group 20.
4. Check every connection in the armature circuit, especially the synchronizing voltage. If it does not come straight from the mains, confirm with an oscilloscope that it is in phase with the same mains phases.
5. Check the thyristors and the armature cabling.
6. Rebuild kit: check the firing pulse and current transformer connections, TypeCode (97.01) = None and S ConvScaleCur (97.02); ConvOvrCur (4.16) equals 2.3 x S ConvScaleCur (97.02).

F501: AuxUnderVolt (Auxiliary undervoltage)

What it means: The auxiliary (electronics) supply dropped too low while the drive was ready to run or running: below 185 VAC on a 230 VAC supply, or below 96 VAC on a 115 VAC supply.^[1][2][3]

Also on: DCS550 (same code and name, different trip levels: below 95 VAC on 230 VAC or 115 VAC supplies, below 140 VDC on a 230 VDC supply; boards SDCS-CON-F and SDCS-PIN-F)

Drive response: Trip level 1 (main, field and fan contactors open at once); active when RdyRun = 1

Likely causes

• Dip or loss of the 115 VAC or 230 VAC auxiliary supply
• Loose wiring or blown fuse in the auxiliary supply
• Faulty SDCS-CON-4 control board or SDCS-PIN-4 / SDCS-POW-4 power supply board

First checks, in this order

1. Measure the auxiliary supply voltage at the drive terminals while the drive is switched on.
2. Check the internal auxiliary voltages on the SDCS-CON-4 board.
3. If the fault returns, change the SDCS-CON-4 and/or the SDCS-PIN-4 or SDCS-POW-4 board.
4. Note: ABB lists F501 among the four faults that the normal Reset does not clear.

F503: ArmOverVolt (Armature overvoltage, DC)

What it means: The armature voltage went above the level set in ArmOvrVoltLev (30.08).^[1][2][3]

Also on: DCS550 (same code and name)

Drive response: Trip level 1 (main, field and fan contactors open at once); monitored always

Likely causes

• ArmOvrVoltLev (30.08) set too low for the system
• Field current too high, for example a field weakening problem
• Field current or EMF controller tuning or flux linearization wrong (group 44)
• Motor driven faster by the load, or overspeed
• Speed scaling wrong, or faulty armature voltage feedback

First checks, in this order

1. Check that ArmOvrVoltLev (30.08) suits the motor and system.
2. Check the field excitation settings in group 44.
3. Check whether the field current is too high and whether field weakening works.
4. Check whether the load accelerated the motor, and check for overspeed.
5. Check the speed scaling in SpeedScaleAct (2.29).
6. Check the armature voltage feedback: connectors X12 and X13 on SDCS-CON-4 and SDCS-PIN-4/51, and the cut voltage coding resistors on SDCS-PIN-51.

F504: ConvOverTemp (Converter overtemperature)

What it means: The thyristor bridge temperature reached the shutdown level in MaxBridgeTemp (4.17). Alarm A104 comes about 5 °C earlier. The drive also trips with F504 if the measured temperature reads below minus 10 °C.^[1][2][3]

Also on: DCS550 (same code and name; its list says converter cover missing instead of door open)

Drive response: Trip level 2 (main and field contactors open, fan keeps running while the fault is pending or FanDly (21.14) runs); monitored always

Likely causes

• Converter fan stopped, turning the wrong way or missing its supply
• Blocked air inlet filter or air outlet, or converter door left open
• High ambient temperature or a load cycle too heavy for the converter
• Temperature measurement connection fault (X12 on SDCS-CON-4, X12 and X22 on SDCS-PIN-4/51)
• Rebuild kit: S MaxBrdgTemp (97.04) set wrong

First checks, in this order

1. Let the converter cool down. Read BridgeTemp (1.24) and the shutdown level MaxBridgeTemp (4.17).
2. Check the converter fan supply voltage, direction of rotation and fan parts.
3. Check that the converter door is closed and the air inlet (filter) and outlet are clear.
4. Check the ambient temperature and the load cycle.
5. Check connector X12 on SDCS-CON-4 and X12 and X22 on SDCS-PIN-4/51.
6. If TypeCode (97.01) = None, check S MaxBrdgTemp (97.04); for D6 and D7 modules set manually, use 50 °C as the absolute maximum.

F508: I/OBoardLoss (I/O board not found or faulty)

What it means: An I/O board or option module that the parameters say is fitted was not found or reports a fault.^[1][2][3]

Also on: DCS550 (same code and name; checks 4.20, 9.11, SDCS-COM-8 and 98.02 to 98.06)

Drive response: Trip level 1 (main, field and fan contactors open at once); monitored always

Likely causes

• Loose or damaged flat cable between SDCS-CON-4 and SDCS-IOB-2 or SDCS-IOB-3
• SDCS-IOB flat cables plugged into X1 or X2 while IO BoardConfig (98.15) = NotUsed
• Option module (encoder, fieldbus, digital or analog extension) selected in group 98 but missing or faulty
• SDCS-COM-8 board problem or wrong DCSLink node ID

First checks, in this order

1. Read Diagnosis (9.11) and Ext IO Status (4.20) to see which board is missing.
2. Check the flat cables between SDCS-CON-4 and SDCS-IOB-2/3.
3. Check the SDCS-COM-8 board, if fitted.
4. Check the option settings: DCSLinkNodeID (94.01), Encoder2Module (98.01), CommModule (98.02), DIO ExtModule1 (98.03), DIO ExtModule2 (98.04), AIO ExtModule (98.06), AIO MotTempMeas (98.12) and IO BoardConfig (98.15).

F512: MainsLowVolt (Mains low (under-) voltage, AC)

What it means: The mains voltage fell below UNetMin1 (30.22) and did not recover within PowrDownTime (30.24), or fell below UNetMin2 (30.23) with PwrLossTrip (30.21) = Immediately. With the On command given, a mains voltage too low for 500 ms sets alarm A111 and after 10 s the drive trips with F512.^[1][2][3]

Also on: DCS550 (same code and name; fuses F100 to F102 on SDCS-PIN-F)

Drive response: Trip level 3 (main contactor opens at once, stop handled by SpeedFbFltMode (30.36)); active when RdyRun = 1

Likely causes

• Missing phase or blown supply fuse
• D1 to D4: blown fuses F100 to F102 on SDCS-PIN-4; D5 to D7: loose U1, V1, W1 connections on SDCS-PIN-51
• Main contactor not closing, or opening during operation
• Mains voltage outside the set tolerance, or NomMainsVolt (99.10) set wrong
• D1 to D4: short circuit or ground fault in the field circuit

First checks, in this order

1. Check PwrLossTrip (30.21), UNetMin1 (30.22), UNetMin2 (30.23) and PowrDownTime (30.24).
2. Check that all 3 phases are present. On D1 to D4 also measure fuses F100 to F102 on SDCS-PIN-4; on D5 to D7 check connections U1, V1 and W1 on SDCS-PIN-51.
3. Check that the mains voltage is within tolerance and the scaling NomMainsVolt (99.10) is right.
4. Check that the main contactor closes and stays closed.
5. Check connectors X12 and X13 on SDCS-CON-4 and SDCS-PIN-4/51 and the voltage coding resistors on SDCS-PIN-51.
6. D1 to D4: check the field circuit for a short circuit or ground fault.
7. Without a UPS for the auxiliary supply, ABB recommends PwrLossTrip (30.21) = Immediately.

F514: MainsNotSync (Mains not in synchronism, AC)

What it means: The firing unit lost synchronism with the mains frequency. Supervision starts once the main contactor is closed and the firing unit has synchronized, which normally takes about 300 ms.^[1][2][3]

Also on: DCS550 (same code and name)

Drive response: Trip level 3 (main contactor opens at once, stop handled by SpeedFbFltMode (30.36)); active when RdyRun = 1

Likely causes

• Loose connection in the mains supply
• Supply interruption or blown fuse
• Mains frequency outside 50 Hz or 60 Hz plus or minus 5 Hz, or unstable (ABB gives a stability figure of df/dt = 17 %/s)

First checks, in this order

1. Check the mains supply connections for a loose terminal.
2. Check the mains supply itself and the fuses.
3. Check the mains frequency and its stability in PLLIn (3.20): one period reads 20,000 at 50 Hz and 16,667 at 60 Hz.

F523: ExtFanAck (External fan acknowledge missing)

What it means: The motor (external) fan acknowledge selected in MotFanAck (10.06) is missing. After the On command the drive closes the fan contactor and waits up to 10 seconds for this acknowledge.^[1][2][3]

Also on: DCS550 (same code and name)

Drive response: Trip level 4 (stop handled by FaultStopMode (30.30)); active when RdyRun = 1

Likely causes

• Motor fan contactor not pulling in
• Fan circuit protection tripped or fan supply voltage missing
• Acknowledge wiring fault or wrong digital input selected

First checks, in this order

1. Check MotFanAck (10.06) and the digital inputs and outputs used (group 14).
2. Check the external fan contactor and fan circuit.
3. Check the external fan supply voltage.

F527: ConvFanAck (Converter fan acknowledge missing)

What it means: The converter cooling fan acknowledge selected in ConvFanAck (10.20) is missing. After the On command the drive closes the fan contactor and waits up to 10 seconds for it.^[1][2]

Drive response: Trip level 4 (stop handled by FaultStopMode (30.30)); active when RdyRun = 1

Likely causes

• Converter fan contactor or fan circuit fault
• Fan thermal switch (klixon) tripped, or failing fan
• Fan supply voltage missing or wrong direction of rotation
• Converter door open or blocked air inlet or outlet
• D6 and D7: air pressure switch not closing

First checks, in this order

1. Check ConvFanAck (10.20), FanDly (21.14) and the digital inputs and outputs used (group 14).
2. Check the converter fan contactor, fan circuit and fan klixon.
3. Check the fan supply voltage, fan parts and direction of rotation.
4. Check that the converter door is closed and the air inlet (filter) and outlet are clear.
5. D6 and D7: check the pressure switch, which should be set to 2 mbar.

F505: ResCurDetect (Residual current detection)

What it means: The sum of the three AC phase currents is not zero, so current is leaking to earth. It is measured by a sum current transformer (ratio 400:1) on AI4 of SDCS-IOB-3 or by an external earth fault relay, as chosen in ResCurDetectSel (30.05).^[1][2]

Drive response: Trip level 1 (main, field and fan contactors open at once); monitored always

Likely causes

• Earth (ground) fault in the armature or field circuit, motor or cabling
• Trip level ResCurDetectLim (30.06) or delay ResCurDetectDel (30.07) set too sensitive
• Faulty sum current transformer or SDCS-IOB-3 board

First checks, in this order

1. Check ResCurDetectSel (30.05), ResCurDetectLim (30.06) and ResCurDetectDel (30.07).
2. Check the sum current transformer; change it or the SDCS-IOB-3 if needed.
3. Disconnect the mains, verify safe isolation in the armature and field circuits, then insulation-test the whole installation with the motor cables disconnected from the drive.

F506: M1OverTemp (Motor 1 measured overtemperature)

What it means: The measured motor 1 temperature (PT100, PTC or klixon) passed the fault limit M1FaultLimTemp (31.07). The motor fan keeps running until the motor is below the alarm level, and the fault cannot be reset while the motor is too hot.^[1][2][3]

Also on: DCS550 (same code and name, Motor measured overtemperature; sensor input on SDCS-CON-F)

Drive response: Trip level 2 (main and field contactors open, fan keeps running); monitored always

Likely causes

• Motor fan stopped, wrong direction or missing supply
• Blocked motor cooling air inlet (filter) or outlet
• High ambient temperature or a load cycle too heavy
• Faulty temperature sensor, sensor cabling or input
• Alarm or fault limit set wrong

First checks, in this order

1. Let the motor cool down.
2. Check M1FaultLimTemp (31.07), M1AlarmLimTemp (31.06), M1KlixonSel (31.08) and the reading in Mot1TempMeas (1.22).
3. Check the motor fan supply, direction of rotation and parts, and the cooling air inlet and outlet.
4. Check the ambient temperature and load cycle.
5. Check the temperature sensors, their cabling and the inputs on SDCS-CON-4 and SDCS-IOB-3.

F507: M1OverLoad (Motor 1 calculated overload)

What it means: The motor thermal model calculates that motor 1 is too hot: the calculated load passed M1FaultLimLoad (31.04). The fault cannot be reset until the model has cooled below the alarm level.^[1][2][3]

Also on: DCS550 (same code and name, Motor calculated overload)

Drive response: Trip level 2 (main and field contactors open, fan keeps running); monitored always

Likely causes

• Motor current above its rating for too long
• Thermal model settings not matched to the motor (31.01, 31.03, 31.04)

First checks, in this order

1. Wait until the motor (thermal model) has cooled down.
2. Check M1FaultLimLoad (31.04) and M1AlarmLimLoad (31.03).
3. Check M1ModelTime (31.01); setting it to zero blocks the thermal model.
4. Check the load and the duty cycle.

F515: M1FexOverCur (Motor 1 field exciter overcurrent)

What it means: The motor 1 field current went above the level set in M1FldOvrCurLev (30.13).^[1][2][3]

Also on: DCS550 (same code and name, Field exciter overcurrent)

Drive response: Trip level 1 (main, field and fan contactors open at once); active when RdyRun = 1

Likely causes

• Field current controller tuning wrong (group 44)
• Field exciter wiring fault
• Insulation fault in the field cables or field winding
• Field winding resistance too low
• Field exciter fault, or the supervision tripping during field autotuning

First checks, in this order

1. If it happens during field exciter autotuning, set M1FldOvrCurLev (30.13) = 135 to disable the supervision for the autotuning.
2. Check M1FldOvrCurLev (30.13) against the nominal field current M1NomFldCur (99.11).
3. Check the field current controller settings in group 44.
4. Check the field exciter connections, the insulation of cables and field winding, and the field winding resistance.
5. Read the fault message on the field exciter (seven-segment display or flashing LEDs).

F516: M1FexCom (Motor 1 field exciter communication loss)

What it means: The drive lost communication with the motor 1 field exciter for longer than FexTimeOut (94.07).^[1][2]

Drive response: Trip level 1 (main, field and fan contactors open at once); active when RdyRun = 1

Likely causes

• Wrong field exciter type selected in M1UsedFexType (99.12)
• Loose flat cable between SDCS-CON-4 and SDCS-PIN-4
• Auxiliary voltage missing on the integrated or external field exciter
• DCSLink cable, termination or node ID fault

First checks, in this order

1. Check M1UsedFexType (99.12) and FexTimeOut (94.07).
2. Check the flat cable between SDCS-CON-4 and SDCS-PIN-4.
3. Check the auxiliary voltage for the integrated and external field exciter.
4. Check the DCSLink cables and termination (DIP switch S1100:1 = ON on DCF803-0016, DCF803-0035 and FEX-425-Int).
5. Check the node IDs: DCSLinkNodeID (94.01), M1FexNode (94.08) or switches S800 and S801 on the exciter.
6. Read the fault message on the field exciter (seven-segment display or flashing LEDs).

F517: ArmCurRipple (Armature current ripple)

What it means: The current ripple monitor sees unequal current between the thyristor pairs, so one or more thyristors are not conducting. The level is set in CurRippleLim (30.19) and CurRippleSel (30.18) chooses fault F517 or alarm A117.^[1][2][3]

Also on: DCS550 (same code and name)

Drive response: Trip level 3 (main contactor opens at once, stop handled by SpeedFbFltMode (30.36)); active when RdyRef = 1

Likely causes

• Blown branch fuse
• Thyristor not firing: gate connection or gate-cathode resistance fault
• Current controller gain too high, M1KpArmCur (43.06)
• Broken current transformer T51 or T52
• Poor mains condition, for example contact problems in the main breaker

First checks, in this order

1. Check CurRippleSel (30.18) and CurRippleLim (30.19).
2. Check M1KpArmCur (43.06) for too high gain.
3. Look at the current feedback with an oscilloscope: 6 pulses should be visible in each mains cycle.
4. Check the branch fuses, the thyristor gate-cathode resistance and gate connections.
5. Check the current transformers T51 and T52 and the mains supply contacts.

F522: SpeedFb (Selected motor, speed feedback)

What it means: The speed feedback check failed: the armature EMF is above EMF FbMonLev (30.15) while the measured speed from the encoder or tacho is below SpeedFbMonLev (30.14). With field weakening the drive trips at once unless two encoders are used.^[1][2][3]

Also on: DCS550 (same code and name, Speed feedback; jumpers on SDCS-CON-F)

Drive response: Trip level 3 (main contactor opens at once, stop handled by SpeedFbFltMode (30.36)); monitored always

Likely causes

• Pulse encoder fault, loose coupling, misalignment, cabling or encoder supply too low
• Analog tacho fault, wrong polarity or voltage, cabling or coupling
• Wrong jumper: S4 (encoder) or S1 (tacho) on SDCS-CON-4
• Armature circuit open, so the EMF measurement is wrong
• Faulty SDCS-CON-4, SDCS-IOB-3 or SDCS-POW-4 board

First checks, in this order

1. Check M1SpeedFbSel (50.03), SpeedFbFltSel (30.17), SpeedFbFltMode (30.36), EMF FbMonLev (30.15) and SpeedFbMonLev (30.14).
2. Encoder: check the encoder, alignment, cabling, coupling, power supply and jumper S4 on SDCS-CON-4.
3. Tacho: check the tacho, its polarity and voltage, alignment, cabling, coupling and jumper S1 on SDCS-CON-4.
4. Check that the circuit between converter and armature is closed.
5. Look for mechanical disturbances on the feedback device.

F521: FieldAck (Selected motor, field acknowledge missing)

What it means: The field exciter did not confirm it was running within 10 seconds of the On command. It is also the sum fault for the field faults F515, F516, F529, F537 and F541.^[1][2]

Drive response: Trip level 1 (main, field and fan contactors open at once); active when RdyRun = 1

Likely causes

• M1UsedFexType (99.12) does not match the fitted field exciter
• One of the field faults F515, F516, F529, F537 or F541
• Field exciter fault or missing field supply

First checks, in this order

1. Check that M1UsedFexType (99.12) matches the field exciter type.
2. Read Mot1FexStatus (6.12) and Mot2FexStatus (6.13).
3. Look in the fault logger for F515, F516, F529, F537 or F541.
4. Read the fault message on the field exciter (seven-segment display or flashing LEDs).

F524: MainContAck (Main contactor acknowledge missing)

What it means: The main contactor acknowledge selected in MainContAck (10.21) is missing. After the On command the drive waits up to 10 seconds for it.^[1][2][3]

Also on: DCS550 (same code and name)

Drive response: Trip level 3 (main contactor opens at once, stop handled by SpeedFbFltMode (30.36)); active when RdyRun = 1

Likely causes

• Main contactor not closing, or its auxiliary relay not switching
• Safety relay chain open
• Acknowledge wiring fault or wrong digital input selected
• MainContCtrlMode (21.16) not matched to the wiring

First checks, in this order

1. Check MainContAck (10.21) and MainContCtrlMode (21.16).
2. Check the switch on and off sequence and the auxiliary relay that switches the main contactor.
3. Check the safety relays.
4. Check the digital inputs and outputs used (group 14).

F526: ExternalDI (External fault via binary input)

What it means: An external device reported a fault through the input chosen in ExtFaultSel (30.31). The drive itself is fine; the cause is in the external equipment.^[1][2][3]

Also on: DCS550 (same code and name)

Drive response: Trip level 1 (main, field and fan contactors open at once); active always or when RdyRun = 1, per 30.33

Likely causes

• Fault in an external device wired to the external fault input
• Wrong input or wrong signal polarity selected

First checks, in this order

1. Find and fix the fault in the external device.
2. Check ExtFaultSel (30.31) and ExtFaultOnSel (30.33), which sets whether the fault is always valid or only after 6 s in RdyRun.
3. If the input must be inverted, invert the digital input.

F528: FieldBusCom (Fieldbus communication loss)

What it means: Cyclic communication with the fieldbus master was lost for longer than FB TimeOut (30.35). The fault only arms after the first data set has arrived; before that only alarm A128 shows.^[1][2][3]

Also on: DCS550 (same code and name)

Drive response: Trip level 5 (stop handled by ComLossCtrl (30.28)); active when FB TimeOut (30.35) is not 0

Likely causes

• Fieldbus master stopped or not sending
• Fieldbus cable, connector or termination fault
• Fieldbus adapter fault or wrong settings in group 51

First checks, in this order

1. Check CommandSel (10.01), ComLossCtrl (30.28), FB TimeOut (30.35) and CommModule (98.02).
2. Check the fieldbus settings in group 51.
3. Check the fieldbus cable and termination.
4. Check the fieldbus adapter.

F531: MotorStalled (Selected motor, motor stalled)

What it means: The motor torque stayed above StallTorq (30.03) for longer than StallTime (30.01) while the speed was below StallSpeed (30.02).^[1][2][3]

Also on: DCS550 (same code and name, Motor stalled)

Drive response: Trip level 3 (main contactor opens at once, stop handled by SpeedFbFltMode (30.36)); active when RdyRef = 1

Likely causes

• Motor mechanically blocked or coupling jammed
• Load too high
• Field current too low
• Current or torque limits wrong (group 20)

First checks, in this order

1. Check the motor and the mechanical couplings for a blockage.
2. Check the load conditions.
3. Check that the field current is correct.
4. Check the current and torque limits in group 20 and the stall settings 30.01 to 30.03.

F532: MotOverSpeed (Selected motor, motor overspeed)

What it means: The motor speed went above M1OvrSpeed (30.16), for example when the load drops in torque control.^[1][2][3]

Also on: DCS550 (same code and name, Motor overspeed)

Drive response: Trip level 3 (main contactor opens at once, stop handled by SpeedFbFltMode (30.36)); monitored always

Likely causes

• Speed controller tuning or speed scaling wrong
• Field current too low
• Speed feedback (encoder, tacho) or its connection faulty
• Motor driven faster by the load
• With EMF feedback: C1 and D1 voltage measurement swapped, or armature circuit open (DC fuses, DC breaker)

First checks, in this order

1. Check M1OvrSpeed (30.16) and the speed controller settings in group 24.
2. Check the speed scaling in SpeedScaleAct (2.29).
3. Compare MotSpeed (1.04) with the speed measured by a hand-held tacho.
4. Check the field current and the speed feedback device and wiring.
5. With EMF feedback, check the C1 and D1 measurement wiring and that the armature circuit is closed.

F537: M1FexRdyLost (Motor 1 field exciter ready lost)

What it means: The motor 1 field exciter dropped its ready signal while working, usually because its AC supply is missing or not in synchronism.^[1][2]

Drive response: Trip level 1 (main, field and fan contactors open at once); active when RdyRun = 1

Likely causes

• Missing phase on the field exciter supply
• Field supply voltage outside tolerance
• Field exciter internal fault

First checks, in this order

1. Check that all phases of the field supply are present.
2. Check that the mains voltage is within the set tolerance.
3. Read the fault message on the field exciter (seven-segment display or flashing LEDs).

F541: M1FexLowCur (Motor 1 field exciter low (under-) current)

What it means: The motor 1 field current fell below M1FldMinTrip (30.12) for longer than FldMinTripDly (45.18).^[1][2][3]

Also on: DCS550 (same code and name, Field exciter low (under-) current)

Drive response: Trip level 1 (main, field and fan contactors open at once); monitored always

Likely causes

• Blown field circuit fuse or field contactor not closed
• Field auxiliary supply voltage missing
• Field or EMF controller tuning wrong (group 44), or field current oscillating
• Minimum trip level set above the motor's minimum field current at full field weakening
• Uncompensated motor with high armature reaction

First checks, in this order

1. Check M1FldMinTrip (30.12) and FldMinTripDly (45.18).
2. Check the motor rating plate for the minimum field current at maximum field weakening (top speed).
3. Check the field circuit fuses, the field auxiliary supply and that the field contactor closes.
4. Check the field excitation settings in group 44 and whether the field current oscillates.
5. Read the fault message on the field exciter (seven-segment display or flashing LEDs).

F525: TypeCode (Type code mismatch)

What it means: The type code setting does not match the converter. On D1, D2, D3, D4 and D4+ modules the type code range is limited to 1190 A DC and 600 VAC.^[1][2][3]

Also on: DCS550 (same code and name; check TypeCode (97.01))

Drive response: Trip level 1 (main, field and fan contactors open at once); monitored always

Likely causes

• TypeCode (97.01) set to a converter that does not match the hardware
• Current or voltage scaling (97.02, 97.03) outside the allowed range

First checks, in this order

1. Check TypeCode (97.01), S ConvScaleCur (97.02) and S ConvScaleVolt (97.03) against the converter rating plate.
2. The type code is write protected; set it manually with ServiceMode (99.06) = SetTypeCode and TypeCode (97.01).
3. Note: ABB lists F525 among the four faults that the normal Reset does not clear.

F513: MainsOvrVolt (Mains overvoltage, AC)

What it means: The mains voltage stayed above 1.3 x NomMainsVolt (99.10) for more than 10 s while the drive was in RdyRun.^[1][2][3]

Also on: DCS550 (same code and name)

Drive response: Trip level 1 (main, field and fan contactors open at once); active when RdyRun = 1

Likely causes

• Supply voltage too high
• NomMainsVolt (99.10) set too low
• Voltage measurement connection or coding resistor fault

First checks, in this order

1. Check that the mains voltage is within the set tolerance.
2. Check the mains voltage scaling NomMainsVolt (99.10).
3. Check connectors X12 and X13 on SDCS-CON-4 and SDCS-PIN-4/51 and the voltage coding resistors on SDCS-PIN-51.

F511: ConvFanCur (Converter fan current)

What it means: The converter fan current is wrong. This check only works with ConvTempDly (97.05) not 0 and a PW-1002/3 fan monitoring board connected to SDCS-PIN-4/51.^[1][2]

Drive response: Trip level 4 (stop handled by FaultStopMode (30.30)); active when RdyRun = 1

Likely causes

• Fan supply voltage missing or wrong direction of rotation
• Worn or blocked fan
• Blocked air inlet or outlet
• Connector fault on X12 (SDCS-CON-4) or X12 and X22 (SDCS-PIN-4/51)

First checks, in this order

1. Check the converter fan supply voltage, direction of rotation and fan parts.
2. Check the cooling air inlet (filter) and outlet.
3. Check connector X12 on SDCS-CON-4 and X12 and X22 on SDCS-PIN-4/51.

F529: M1FexNotOK (Motor 1 field exciter not okay)

What it means: The motor 1 field exciter found a fault in its self-diagnosis, or lost power.^[1][2]

Drive response: Trip level 1 (main, field and fan contactors open at once); monitored always

Likely causes

• Field contactor, or the main contactor with an OnBoard field exciter, not closed or closing too late
• Field exciter power failure
• Faulty field exciter

First checks, in this order

1. Check that the field contactor (or the main contactor for an OnBoard field exciter) closes in time.
2. Read the fault message on the field exciter (seven-segment display or flashing LEDs).
3. Change the field exciter if it is faulty.

F546: LocalCmdLoss (Local command loss)

What it means: In local mode, communication with the DCS800 Control Panel, DriveWindow or DriveWindow Light was lost (fixed 5 s time out).^[1][2][3]

Also on: DCS550 (same code and name)

Drive response: Trip level 5 (stop handled by LocalLossCtrl (30.27)); active in local mode

Likely causes

• Control panel unplugged while it had control
• Faulty connection adapter or cable
• PC tool connection lost

First checks, in this order

1. Check LocalLossCtrl (30.27), which sets how the drive stops.
2. Check whether the control panel was disconnected.
3. Check the connection adapter and cables.

F547: HwFailure (Hardware failure)

What it means: The drive found a hardware failure. Diagnosis (9.11) tells which one.^[1][2][3]

Also on: DCS550 (same code and name)

Drive response: Trip level 1 (main, field and fan contactors open at once); monitored always

Likely causes

• Internal hardware fault on a drive board

First checks, in this order

1. Read Diagnosis (9.11) for details.
2. Note: ABB lists F547 among the four faults that the normal Reset does not clear; contact ABB service if it persists.

F548: FwFailure (Firmware failure)

What it means: The drive found a firmware failure. It can happen after a firmware download through a USB to COM port converter.^[1][2][3]

Also on: DCS550 (same code and name)

Drive response: Trip level 1 (main, field and fan contactors open at once); monitored always

Likely causes

• Corrupt or failed firmware download
• Firmware fault

First checks, in this order

1. Read Diagnosis (9.11) for details.
2. If a firmware download was just made through a USB to COM converter, repeat the download.
3. Note: ABB lists F548 among the four faults that the normal Reset does not clear.

F549: ParComp (Parameter compatibility)

What it means: While downloading a parameter set or at power-up, the firmware could not write one or more parameter values, so it set them to default.^[1][2][3]

Also on: DCS550 (same code and name)

Drive response: Trip level 1 (main, field and fan contactors open at once); monitored always

Likely causes

• Parameter set from a different firmware or drive
• Value outside the allowed range

First checks, in this order

1. Find the parameters that caused it in Diagnosis (9.11).
2. Check and correct those parameter settings.

F550: ParMemRead (Parameter or Memory Card read)

What it means: Reading the active parameter set or a user parameter set from the flash or the Memory Card failed (checksum fault).^[1][2][3]

Also on: DCS550 (same code and name, Parameter read; checks SDCS-CON-F)

Drive response: Trip level 1 (main, field and fan contactors open at once); monitored always

Likely causes

• User1 or User2 parameter set not saved properly
• Faulty Memory Card
• Faulty SDCS-CON-4 board

First checks, in this order

1. Check that the user parameter sets were saved properly, see ApplMacro (99.08).
2. Check the Memory Card.
3. Check the SDCS-CON-4 board.

F551: AIRange (Analog input range)

What it means: An analog input set to 4 to 20 mA or 2 to 10 V fell below 4 mA or 2 V, which points to a broken wire. AI Mon4mA (30.29) chooses this fault, or alarm A127 with the drive running on.^[1][2][3]

Also on: DCS550 (same code and name)

Drive response: Trip level 4 (stop handled by FaultStopMode (30.30)); monitored always

Likely causes

• Broken or loose analog signal wire
• Signal source failed
• Wrong polarity

First checks, in this order

1. Check AI Mon4mA (30.29).
2. Check the connections and cables of the analog inputs used.
3. Check the polarity of the connection.

F552: MechBrake (Selected motor, mechanical brake)

What it means: The brake open or brake closed acknowledge is missing, or during torque proving the actual torque did not reach StrtTorqRef (42.08).^[1][2]

Drive response: Trip level 3 (main contactor opens at once, stop handled by SpeedFbFltMode (30.36)); monitored always

Likely causes

• Brake not opening or closing
• Brake acknowledge wiring fault
• Brake settings in group 42 wrong

First checks, in this order

1. Check M1BrakeAckSel (42.02), M1BrakeFltTime (42.05), BrakeFaultFunc (42.06), M1StrtTorqRefSel (42.07) and M1BrakeLongTime (42.12).
2. Check the brake and its cabling.
3. Check the digital inputs and outputs used (group 14).

F553: TachPolarity (Selected motor, tacho polarity)

What it means: The polarity of the analog tacho or pulse encoder, chosen in M1SpeedFbSel (50.03), does not agree with the armature EMF.^[1][2][3]

Also on: DCS550 (same code and name, Tacho polarity)

Drive response: Trip level 3 (main contactor opens at once, stop handled by SpeedFbFltMode (30.36)); monitored always

Likely causes

• Tacho cable polarity reversed
• Encoder channels swapped
• Armature or field cables reversed, so the motor turns the other way

First checks, in this order

1. Check EMF FbMonLev (30.15) and SpeedFbMonLev (30.14).
2. Check the polarity of the tacho cable.
3. Check the encoder cable polarity (for example swap channels A and A not).
4. Check the polarity of the armature and field cables and the motor direction of rotation.

F554: TachoRange (Selected motor, tacho range)

What it means: The analog tacho input (AITacho) is about to overflow, so the tacho voltage is too high for the terminal used.^[1][2][3]

Also on: DCS550 (same code and name, Tacho range; terminals X1:1 to X1:4 on SDCS-CON-F)

Drive response: Trip level 3 (main contactor opens at once, stop handled by SpeedFbFltMode (30.36)); monitored always

Likely causes

• Tacho wired to the wrong voltage range terminal
• Tacho voltage higher than expected at top speed

First checks, in this order

1. Check the tacho connections on X3:1 to X3:4 of SDCS-CON-4.
2. If M1OvrSpeed (30.16) was changed, repeat the tacho fine tuning with ServiceMode (99.06) = TachFineTune.

F557: ReversalTime (Reversal time)

What it means: After a command to reverse the current, the opposite current was not reached before ZeroCurTimeOut (97.19) elapsed.^[1][2][3]

Also on: DCS550 (same code and name)

Drive response: Trip level 3 (main contactor opens at once, stop handled by SpeedFbFltMode (30.36)); active when RdyRef = 1

Likely causes

• Highly inductive motor or load
• Motor voltage too high compared with the mains voltage
• Reversal delay RevDly (43.14) too long for the time out

First checks, in this order

1. Check for a highly inductive motor.
2. Check whether the motor voltage is too high compared with the mains voltage.
3. Lower RevDly (43.14) if possible.
4. Increase ZeroCurTimeOut (97.19).

F539: FastCurRise (Fast current rise)

What it means: The armature current rose too fast (di/dt) while generating, above ArmCurRiseMax (30.10). If fitted, the DC breaker trips and the main contactor opens.^[1][2]

Drive response: Trip level 1 (main, field and fan contactors open at once); active when RdyRef = 1 and generating

Likely causes

• Very fast current rise while regenerating, for example after a commutation failure
• ArmCurRiseMax (30.10) set too low

First checks, in this order

1. Check ArmCurRiseMax (30.10).
2. Check the mains supply for dips while the drive was regenerating.
3. Check the DC breaker, if fitted.

F544: P2PandMFCom (Peer to peer and master-follower communication loss)

What it means: Communication over DCSLink between drives (peer to peer mailboxes or master-follower) was lost.^[1][2]

Drive response: Trip level 5 (stop handled by ComLossCtrl (30.28)); monitored always

Likely causes

• DCSLink cable, termination or node ID fault
• Mailbox settings in group 94 wrong
• Firmware 3.6 or lower mixed with firmware 3.7 or higher on the same link

First checks, in this order

1. Check FirmwareVer (4.01) on all drives; do not mix 3.6 and lower with 3.7 and higher.
2. Check ComLossCtrl (30.28), MailBox1 to MailBox4 (94.12, 94.18, 94.24, 94.30) and MailBoxCycle1 to MailBoxCycle4 (94.13, 94.19, 94.25, 94.31).
3. Check the DCSLink cables, termination and DCSLinkNodeID (94.01).

F543: COM8Com (SDCS-COM-8 communication loss)

What it means: The SDCS-COM-8 fiber optic communication to the overriding control (channel 0) or between master and followers (channel 2) was lost.^[1][2][3]

Also on: DCS550 (same code and name)

Drive response: Trip level 5 (stop handled by the channel loss control, 70.05 or 70.15); active when RdyOn = 1

Likely causes

• Damaged or unplugged fiber optic cable
• Overriding control adapter fault
• Time out or loss control settings wrong

First checks, in this order

1. Check CommandSel (10.01), Ch0 ComLossCtrl (70.05), Ch0 TimeOut (70.04), Ch2 ComLossCtrl (70.15), Ch2 TimeOut (70.14) and Ch0 DriveBus (71.01).
2. Check the fiber optic cables to the overriding control (channel 0) and between master and followers (channel 2).
3. Check the overriding control adapters.

F540: COM8Faulty (SDCS-COM-8 faulty)

What it means: The SDCS-COM-8 communication board is faulty.^[1][2][3]

Also on: DCS550 (same code and name; SDCS-CON-F)

Drive response: Trip level 1 (main, field and fan contactors open at once); active when RdyOn = 1

Likely causes

• Failed SDCS-COM-8 board
• Failed SDCS-CON-4 control board

First checks, in this order

1. Change the SDCS-COM-8 and/or the SDCS-CON-4 board.

F545: ApplLoadFail (Application load failure)

What it means: Loading the application program failed.^[1][2]

Drive response: Trip level 1 (main, field and fan contactors open at once); monitored always

Likely causes

• Application program could not be loaded; Diagnosis (9.11) gives the reason

First checks, in this order

1. Read Diagnosis (9.11) for details.

F556: TorqProving (Selected motor, torque proving)

What it means: The torque proving acknowledge did not arrive while M1TorqProvTime (42.10) was running.^[1][2]

Drive response: Trip level 3 (main contactor opens at once, stop handled by SpeedFbFltMode (30.36)); active while 42.10 runs

Likely causes

• Adaptive Program, application program or overriding control not sending TorqProvOK
• Torque proving time too short

First checks, in this order

1. Check M1TorqProvTime (42.10).
2. Check the source of the acknowledge TorqProvOK [AuxCtrlWord2 (7.03) bit 11].

F509: M2OverTemp (Motor 2 measured overtemperature)

What it means: The measured motor 2 temperature passed M2FaultLimTemp (49.37). The fault cannot be reset while the motor is too hot.^[1][2]

Drive response: Trip level 2 (main and field contactors open, fan keeps running); monitored always

Likely causes

• Motor 2 fan or cooling air problem
• High ambient temperature or heavy load cycle
• Sensor or cabling fault, or limits set wrong

First checks, in this order

1. Let the motor cool down.
2. Check M2FaultLimTemp (49.37), M2AlarmLimTemp (49.36) and M2KlixonSel (49.38).
3. Check the motor fan supply, rotation and parts, and the cooling air inlet and outlet.
4. Check the temperature sensors, cabling and inputs on SDCS-CON-4 and SDCS-IOB-3.

F510: M2OverLoad (Motor 2 calculated overload)

What it means: The thermal model calculates that motor 2 is too hot: above M2FaultLimLoad (49.34). The fault cannot be reset until the model cools.^[1][2]

Drive response: Trip level 2 (main and field contactors open, fan keeps running); monitored always

Likely causes

• Motor 2 current above its rating for too long
• Thermal model settings not matched to motor 2

First checks, in this order

1. Wait until the motor (thermal model) has cooled down.
2. Check M2FaultLimLoad (49.34) and M2AlarmLimLoad (49.33).

F518: M2FexOverCur (Motor 2 field exciter overcurrent)

What it means: The motor 2 field current went above M2FldOvrCurLev (49.09).^[1][2]

Drive response: Trip level 1 (main, field and fan contactors open at once); active when RdyRun = 1

Likely causes

• Field current controller tuning wrong (group 49)
• Field wiring, cable or winding insulation fault
• Field winding resistance too low, or field exciter fault

First checks, in this order

1. Check M2FldOvrCurLev (49.09) and the field settings in group 49.
2. Check the field exciter connections, cable and winding insulation, and winding resistance.
3. Read the fault message on the field exciter (seven-segment display or flashing LEDs).

F519: M2FexCom (Motor 2 field exciter communication loss)

What it means: The drive lost communication with the motor 2 field exciter for longer than FexTimeOut (94.07).^[1][2]

Drive response: Trip level 1 (main, field and fan contactors open at once); active when RdyRun = 1

Likely causes

• Wrong field exciter type in M2UsedFexType (49.07)
• Flat cable, auxiliary voltage or DCSLink fault

First checks, in this order

1. Check M2UsedFexType (49.07) and FexTimeOut (94.07).
2. Check the flat cable between SDCS-CON-4 and SDCS-PIN-4 and the auxiliary voltage for the field exciter.
3. Check the DCSLink cables, termination (S1100:1 = ON) and node IDs: DCSLinkNodeID (94.01), M2FexNode (94.09) or switches S800 and S801.

F530: M2FexNotOK (Motor 2 field exciter not okay)

What it means: The motor 2 field exciter found a fault in its self-diagnosis, or lost power.^[1][2]

Drive response: Trip level 1 (main, field and fan contactors open at once); monitored always

Likely causes

• Field or main contactor not closed or closing too late
• Field exciter power failure or faulty exciter

First checks, in this order

1. Check that the field contactor (or the main contactor for an OnBoard field exciter) closes in time.
2. Read the fault message on the field exciter and change the exciter if it is faulty.

F538: M2FexRdyLost (Motor 2 field exciter ready lost)

What it means: The motor 2 field exciter dropped its ready signal while working, usually because its AC supply is missing or not in synchronism.^[1][2]

Drive response: Trip level 1 (main, field and fan contactors open at once); active when RdyRun = 1

Likely causes

• Missing phase or field supply outside tolerance
• Field exciter internal fault

First checks, in this order

1. Check that all phases are present and the mains voltage is within tolerance.
2. Read the fault message on the field exciter (seven-segment display or flashing LEDs).

F542: M2FexLowCur (Motor 2 field exciter low (under-) current)

What it means: The motor 2 field current fell below M2FldMinTrip (49.08) for longer than FldMinTripDly (45.18).^[1][2]

Drive response: Trip level 1 (main, field and fan contactors open at once); monitored always

Likely causes

• Blown field fuse, field contactor open or field supply missing
• Field tuning wrong or field current oscillating
• Trip level above the motor's minimum field current

First checks, in this order

1. Check M2FldMinTrip (49.08) and FldMinTripDly (45.18) against the motor rating plate.
2. Check the field circuit fuses, field auxiliary supply and field contactor.
3. Read the fault message on the field exciter.

F533: 12PRevTime (12-pulse reversal timeout)

What it means: In a 12-pulse system the current direction did not change before 12P RevTimeOut (47.05) elapsed.^[1][2]

Drive response: Trip level 3 (main contactor opens at once, stop handled by SpeedFbFltMode (30.36)); active when RdyRef = 1

Likely causes

• Highly inductive motor
• Motor voltage too high compared with the mains voltage

First checks, in this order

1. Check for a highly inductive motor and increase 12P RevTimeOut (47.05) if needed.
2. Check the motor voltage against the mains voltage.

F534: 12PCurDiff (12-pulse current difference)

What it means: In 12-pulse parallel operation, the current difference between the two converters is too large.^[1][2]

Drive response: Trip level 3 (main contactor opens at once, stop handled by SpeedFbFltMode (30.36)); monitored always

Likely causes

• Difference limit or delay set too tight
• Armature current controller settings unequal or wrong

First checks, in this order

1. Check DiffCurLim (47.02) and DiffCurDly (47.03).
2. Check the armature current controller settings in group 43.

F535: 12PulseCom (12-pulse communication)

What it means: Communication between the 12-pulse master and slave over DCSLink was lost.^[1][2]

Drive response: Trip level 3 (main contactor opens at once, stop handled by SpeedFbFltMode (30.36)); active when RdyOn = 1

Likely causes

• DCSLink cable, termination or node ID fault
• Time out set too short

First checks, in this order

1. Check 12P TimeOut (94.03).
2. Check the DCSLink cables and termination.
3. Check DCSLinkNodeID (94.01) and 12P SlaNode (94.04).

F536: 12PSlaveFail (12-pulse slave failure)

What it means: The 12-pulse master tripped because the 12-pulse slave has a fault.^[1][2]

Drive response: Trip level 4 (stop handled by FaultStopMode (30.30)); active when RdyOn = 1

Likely causes

• Any fault on the 12-pulse slave drive

First checks, in this order

1. Read the fault logger of the 12-pulse slave and fix that fault.

A101: Off2ViaDI (Off2, Emergency Off / Coast stop, pending via digital input)

What it means: The Off2 (coast stop) input is active, so the drive is inhibited from starting. The drive itself is fine.^[1][2][3]

Also on: DCS550 (same code and name)

Drive response: Alarm level 1: indication; after a stop the main contactor cannot close again until it clears; active when RdyRun = 1

Likely causes

• Off2 circuit open (emergency off or coast stop chain)
• Off2 input not inverted although the signal is low active

First checks, in this order

1. Check the Off2 circuit and the input chosen in Off2 (10.08).
2. If needed, invert the signal (group 10); the signal should be low active.

A102: Off3ViaDI (Off3, E-stop, pending via digital input)

What it means: The emergency stop (Off3) input is active. The drive itself is fine; it will not start until the E-stop is released. The panel and DriveWindow show it as 102 Off3ViaDI.^[1][2][3]

Also on: DCS550 (same code and name)

Drive response: Alarm level 1: indication; after a stop the main contactor cannot close again until it clears; active when RdyRun = 1

Likely causes

• E-stop button pressed or E-stop chain open
• E-stop input not inverted although the signal is low active

First checks, in this order

1. Release the E-stop and check the E-stop circuit.
2. Check E Stop (10.09); invert the signal in group 10 if needed (the signal should be low active).

A104: ConvOverTemp (Converter overtemperature)

What it means: The converter bridge is about 5 °C below its shutdown temperature MaxBridgeTemp (4.17). If it keeps rising the drive trips with F504.^[1][2][3]

Also on: DCS550 (same code and name)

Drive response: Alarm level 2: drive runs on, fan stays on while pending; monitored always

Likely causes

• Converter fan or fan acknowledge problem
• Blocked air inlet or outlet, or door open
• High ambient temperature or heavy load cycle

First checks, in this order

1. Check ConvFanAck (10.20) and FanDly (21.14).
2. Check the converter fan supply, direction of rotation and parts.
3. Check that the door is closed and the air inlet (filter) and outlet are clear.
4. Check the ambient temperature and the load cycle.

A106: M1OverTemp (Motor 1 measured overtemperature)

What it means: The measured motor 1 temperature passed the alarm limit M1AlarmLimTemp (31.06). At the fault limit (31.07) the drive trips with F506.^[1][2][3]

Also on: DCS550 (same code and name)

Drive response: Alarm level 2: drive runs on, fan stays on while pending; monitored always

Likely causes

• Motor fan or cooling air problem
• High ambient temperature or heavy load cycle
• Sensor or cabling fault

First checks, in this order

1. Check M1AlarmLimTemp (31.06) and the reading in Mot1TempMeas (1.22).
2. Check the motor fan and cooling air path.
3. Check the temperature sensors and their inputs on SDCS-CON-4 and SDCS-IOB-3.

A107: M1OverLoad (Motor 1 calculated overload)

What it means: The motor thermal model has passed the alarm limit M1AlarmLimLoad (31.03). At the fault limit (31.04) the drive trips with F507.^[1][2][3]

Also on: DCS550 (same code and name)

Drive response: Alarm level 2: drive runs on, fan stays on while pending; monitored always

Likely causes

• Motor current above its rating for a long time
• Thermal model settings not matched to the motor

First checks, in this order

1. Check M1AlarmLimLoad (31.03).
2. Check M1ModelTime (31.01); zero blocks the thermal model.
3. Reduce the load or check the duty cycle.

A109: M2OverTemp (Motor 2 measured overtemperature)

What it means: The measured temperature of motor 2 has passed the alarm limit M2AlarmLimTemp (49.36). At the fault limit M2FaultLimTemp (49.37) the drive trips with F509.^[1]

Drive response: Alarm level 2: drive runs on, fan stays on while pending; monitored always

Likely causes

• Motor 2 fan without supply, turning the wrong way or faulty
• Cooling air inlet (filter) or outlet blocked, or ambient temperature too high
• Load cycle too heavy for the motor
• Temperature sensor or its cabling faulty

First checks, in this order

1. Check M2AlarmLimTemp (49.36).
2. Check the motor 2 temperature, the fan supply voltage, its direction of rotation and its components.
3. Check the cooling air inlet (for example the filter), the outlet and the ambient temperature.
4. Check the load cycle.
5. Check the motor temperature sensors and cabling, and the sensor inputs on SDCS-CON-4 and SDCS-IOB-3.

A110: M2OverLoad (Motor 2 calculated overload)

What it means: The motor 2 thermal model has passed the alarm limit M2AlarmLimLoad (49.33), in percent of M2NomCur (49.02). At the fault limit M2FaultLimLoad (49.34) the drive trips with F510.^[1]

Drive response: Alarm level 2: drive runs on, fan stays on while pending; monitored always

Likely causes

• Motor 2 current above its rating for a long time
• Thermal model settings not matched to the motor

First checks, in this order

1. Check M2AlarmLimLoad (49.33).
2. Check M2ModelTime (49.32); zero blocks the thermal model.
3. Reduce the load or check the duty cycle.

A111: MainsLowVolt (Mains low (under-) voltage, AC)

What it means: The mains voltage dropped below UNetMin1 (30.22). The drive holds firing at 150 degrees with single pulses and restarts by itself if the voltage returns within PowrDownTime (30.24); otherwise it trips with F512.^[1][2][3]

Also on: DCS550 (same code and name)

Drive response: Alarm level 3: auto-reclosing, firing angle set to 150 degrees, drive restarts when the condition clears; active when RdyRun = 1

Likely causes

• Short mains dip or missing phase
• Main contactor opening
• Mains voltage scaling NomMainsVolt (99.10) wrong

First checks, in this order

1. Check PwrLossTrip (30.21), UNetMin1 (30.22) and UNetMin2 (30.23).
2. Check that all 3 phases are present and within tolerance.
3. Check that the main contactor closes and stays closed.
4. Check NomMainsVolt (99.10) and connectors X12 and X13 on SDCS-CON-4 and SDCS-PIN-4/51.

A114: ArmCurDev (Armature current deviation)

What it means: The armature current has differed from its reference by more than 20 % of nominal motor current for over 5 s, so the current controller cannot follow. Usually the incoming voltage is too low for the motor EMF.^[1][2][3]

Also on: DCS550 (same code and name)

Drive response: Alarm level 4: indication only; active when RdyRef = 1

Likely causes

• Blown DC fuses
• Mains voltage too low, or motor armature voltage too high for the mains
• ArmAlphaMin (20.15) set too high

First checks, in this order

1. Check the DC fuses.
2. Check the ratio between mains voltage and armature voltage.
3. Check ArmAlphaMin (20.15).
4. For non-motor loads the alarm can be blocked with AuxCtrlWord2 (7.03) bit 6.

A117: ArmCurRipple (Armature current ripple)

What it means: Same check as F517, set to alarm by CurRippleSel (30.18): one or more thyristors are not conducting.^[1][2][3]

Also on: DCS550 (same code and name)

Drive response: Alarm level 4: indication only; active when RdyRef = 1

Likely causes

• Blown branch fuse or thyristor not firing
• Current controller gain too high, M1KpArmCur (43.06)
• Broken current transformer T51 or T52, or poor mains condition

First checks, in this order

1. Check CurRippleSel (30.18), CurRippleLim (30.19) and M1KpArmCur (43.06).
2. Look at the current feedback with an oscilloscope for 6 pulses per cycle.
3. Check branch fuses, thyristor gates and current transformers T51 and T52.

A118: FoundNewAppl (Found new application on Memory Card)

What it means: The drive found an application on the Memory Card that is not active yet.^[1]

Drive response: Alarm level 1: indication; after a stop the main contactor cannot close again until it clears; active directly after the auxiliary supply is switched on

Likely causes

• A Memory Card with a new application was plugged in

First checks, in this order

1. Activate the application on the Memory Card with ParApplSave (16.06) = EableAppl.

A119: ApplDiff (Application on drive and Memory Card are different)

What it means: The application in the drive and the application on the Memory Card are different.^[1]

Drive response: Alarm level 1: indication; after a stop the main contactor cannot close again until it clears; active directly after the auxiliary supply is switched on

Likely causes

• A Memory Card holding a different application from the one in the drive

First checks, in this order

1. Activate the application on the Memory Card with ParApplSave (16.06) = EableAppl.

A121: AutotuneFail (Autotuning failed)

What it means: An autotuning run did not finish successfully.^[1][2][3]

Also on: DCS550 (same code and name)

Drive response: Alarm level 4: indication only; monitored always

Likely causes

• Autotuning interrupted or conditions not met (see Diagnosis)

First checks, in this order

1. Read Diagnosis (9.11) for the reason.
2. Clear the alarm by setting ServiceMode (99.06) = NormalMode, then repeat the autotuning.

A123: FaultSuppres (Fault suppressed)

What it means: At least one fault message is active and suppressed.^[1]

Drive response: Alarm level 4: indication only; monitored always

Likely causes

• An active fault that the drive is suppressing

First checks, in this order

1. Read FaultWord1 to FaultWord4 (9.01 to 9.04) and UserFaultWord (9.05) to see which fault is active.
2. Look that fault up in this table and work through its checks.

A125: SpeedFb (Selected motor, speed feedback)

What it means: Same check as F522, set to alarm by SpeedFbFltSel (30.17): the speed feedback failed, so the drive switched to EMF feedback, or to the second encoder when two are fitted.^[1][2][3]

Also on: DCS550 (same code and name)

Drive response: Alarm level 4: indication only; monitored always

Likely causes

• Encoder or tacho fault, coupling, alignment or cabling
• Wrong jumper S4 or S1 on SDCS-CON-4
• Armature circuit open

First checks, in this order

1. Check M1SpeedFbSel (50.03), SpeedFbFltSel (30.17), SpeedFbFltMode (30.36), EMF FbMonLev (30.15) and SpeedFbMonLev (30.14).
2. Check the encoder or tacho, its supply, cabling and coupling.

A126: ExternalDI (External alarm via binary input)

What it means: An external device reported an alarm through the input chosen in ExtAlarmSel (30.32). The drive itself is fine.^[1][2][3]

Also on: DCS550 (same code and name)

Drive response: Alarm level 4: indication only; monitored always

Likely causes

• Alarm in external equipment wired to the input

First checks, in this order

1. Check the external device.
2. Check ExtAlarmSel (30.32) (alarm when the input is 0) and ExtAlarmOnSel (30.34).

A127: AIRange (Analog input range)

What it means: An analog input set to 4 to 20 mA or 2 to 10 V fell below 4 mA or 2 V. AI Mon4mA (30.29) lets the drive run on at the last speed or at FixedSpeed1 (23.02) with this alarm.^[1][2][3]

Also on: DCS550 (same code and name)

Drive response: Alarm level 4: indication only; monitored always

Likely causes

• Broken or loose analog signal wire
• Signal source failed or wrong polarity

First checks, in this order

1. Check AI Mon4mA (30.29).
2. Check the analog input connections, cables and polarity.

A128: FieldBusCom (Fieldbus communication loss)

What it means: Fieldbus communication is missing. Before the first data set from the overriding control arrives only this alarm shows; after that a loss gives F528 or this alarm, per ComLossCtrl (30.28).^[1][2][3]

Also on: DCS550 (same code and name)

Drive response: Alarm level 4: indication only; active when FB TimeOut (30.35) is not 0

Likely causes

• Overriding control not yet started or not sending
• Fieldbus cable, termination or adapter fault
• Wrong settings in group 51

First checks, in this order

1. Check ComLossCtrl (30.28), FB TimeOut (30.35) and CommModule (98.02).
2. Check the group 51 settings, the fieldbus cable, termination and adapter.

A130: LocalCmdLoss (Local command loss)

What it means: The connection to the DCS800 Control Panel, DriveWindow or DriveWindow Light was lost in local mode, and LocalLossCtrl (30.27) is set to alarm.^[1][2][3]

Also on: DCS550 (same code and name)

Drive response: Alarm level 4: indication only; active in local mode

Likely causes

• Panel unplugged, faulty cable or connection adapter
• PC tool connection lost

First checks, in this order

1. Check LocalLossCtrl (30.27).
2. Check whether the panel was disconnected, and check the adapter and cables.

A133: RetainInv (Retain data invalid)

What it means: At power-up the retain data in the flash were invalid, so the drive used the backup data, which show the state at the previous power-up. Retain data include the fault logger, Data1 to Data4 (19.01 to 19.04), the I/O options (group 98) and parameters marked RETAIN in DCS800 ControlBuilder.^[1]

Drive response: Alarm level 4: indication only; active directly after the electronics are switched on, for at most 10 s

Likely causes

• Auxiliary voltage switched off about 2 seconds after power-up, while the retain data sector was being rearranged
• Defective flash on the SDCS-CON-4
• Problem with the auxiliary power supply

First checks, in this order

1. Check the auxiliary power supply.
2. Check whether the flash of the SDCS-CON-4 is defective.

A134: ParComp (Parameter compatibility)

What it means: When a parameter set was downloaded, or at power-up, a parameter could not be written or was not compatible, so the drive set it to its default. Diagnosis (9.11) shows which parameters caused it.^[1]

Drive response: Alarm level 4: indication only; active after a parameter set download, for at most 10 s

Likely causes

• A parameter value that is not possible or not compatible with this drive

First checks, in this order

1. Read Diagnosis (9.11) to find the parameters.
2. Check those parameter settings; they are now at their defaults.

A135: ParUpDwnLoad (Parameter up- or download failed)

What it means: The checksum check failed during a parameter up- or download, or two or more parameter set actions were requested at the same time.^[1]

Drive response: Alarm level 4: indication only; active after a parameter up- or download, for at most 10 s

Likely causes

• Checksum failure during the transfer
• Two or more parameter set actions requested at the same time

First checks, in this order

1. Try the up- or download again.
2. Request one parameter set action at a time.

A136: NoAPTaskTime (Adaptive Program task time not set)

What it means: The Adaptive Program was started, but its task time is not set.^[1]

Drive response: Alarm level 4: indication only; monitored always

Likely causes

• TimeLevSel (83.04) not set while AdapProgCmd (83.01) is Start, SingleCycle or SingleStep

First checks, in this order

1. Set TimeLevSel (83.04) to 5 ms, 20 ms, 100 ms or 500 ms when AdapProgCmd (83.01) is Start, SingleCycle or SingleStep.

A137: SpeedNotZero (Speed not zero)

What it means: A restart is blocked because the motor has not reached zero speed, M1ZeroSpeedLim (20.03), after a normal stop with FlyStart (21.10) = StartFrom0, a coast stop, an E-stop, or a power off and on.^[1][2][3]

Also on: DCS550 (same code and name)

Drive response: Alarm level 1: after a stop the main contactor cannot close again until it clears; not active when RdyRef = 1

Likely causes

• Motor still turning when the restart was given
• Zero speed limit set too low
• Speed feedback device faulty, so zero speed is never seen

First checks, in this order

1. Set On and Run to 0 and check that the actual speed is within the zero speed limit.
2. Check M1ZeroSpeedLim (20.03), FlyStart (21.10) and M1SpeedFbSel (50.03).
3. Check that the tacho or encoder works properly.

A138: Off2FieldBus (Off2, Emergency Off / Coast Stop, pending via MainCtrlWord / fieldbus)

What it means: The overriding control or fieldbus is sending Off2 (coast stop) in MainCtrlWord (7.01) bit 1, so the drive is inhibited from starting. The drive itself is fine.^[1][2][3]

Also on: DCS550 (same code and name)

Drive response: Alarm level 1: after a stop the main contactor cannot close again until it clears; active when RdyRun = 1

Likely causes

• Overriding control holding Off2N low
• Fieldbus control word not yet sent or wrongly mapped

First checks, in this order

1. Check MainCtrlWord (7.01) bit 1 Off2N from the overriding control.

A139: Off3FieldBus (Off3, E-stop, pending via MainCtrlWord / fieldbus)

What it means: The overriding control or fieldbus is sending Off3 (E-stop) in MainCtrlWord (7.01) bit 2. The drive itself is fine.^[1][2][3]

Also on: DCS550 (same code and name)

Drive response: Alarm level 1: after a stop the main contactor cannot close again until it clears; active when RdyRun = 1

Likely causes

• Overriding control holding Off3N low
• Fieldbus control word not yet sent or wrongly mapped

First checks, in this order

1. Check MainCtrlWord (7.01) bit 2 Off3N from the overriding control.

A103: DC BreakAck (Selected motor, DC-Breaker acknowledge missing)

What it means: The DC breaker acknowledge is missing. Firing is held at 150 degrees with single pulses, so the drive cannot start or restart.^[1][2][3]

Also on: DCS550 (same code and name)

Drive response: Alarm level 3: firing angle set to 150 degrees, single firing pulses, drive restarts when the condition clears; active when RdyRun = 1

Likely causes

• DC breaker open or tripped
• Acknowledge wiring fault or wrong signal polarity

First checks, in this order

1. Check the DC breaker.
2. Check DC BreakAck (10.23) and invert the signal in group 10 if needed.

A105: DynBrakeAck (Selected motor, dynamic braking is still pending)

What it means: Dynamic braking is still active, so the drive cannot start or restart (unless FlyStart (21.10) = FlyStartDyn).^[1][2][3]

Also on: DCS550 (same code and name)

Drive response: Alarm level 3: firing angle set to 150 degrees, single firing pulses, drive restarts when the condition clears; active when RdyRun = 1

Likely causes

• Dynamic braking contactor still closed
• Acknowledge wiring fault

First checks, in this order

1. Check DynBrakeAck (10.22) and the dynamic braking circuit.
2. Check FlyStart (21.10).

A113: COM8Com (SDCS-COM-8 communication loss)

What it means: Communication through the SDCS-COM-8 board is missing. ABB notes that with A113 the drive is still waiting for the very first data set from the overriding control or master.^[1][2][3]

Also on: DCS550 (same code and name)

Drive response: Alarm level 4: indication only; monitored always

Likely causes

• Fiber optic cable to the overriding control (channel 0) or between master and followers (channel 2) not connected
• Overriding control or its settings not ready

First checks, in this order

1. Check CommandSel (10.01), Ch0 ComLossCtrl (70.05), Ch0 TimeOut (70.04), Ch2 ComLossCtrl (70.15), Ch2 TimeOut (70.14) and Ch0 DriveBus (71.01).
2. Check the fiber optic cables, the overriding control adapters and the overriding control settings.

A112: P2PandMFCom (Peer to peer and master-follower communication loss)

What it means: DCSLink communication between drives was lost and ComLossCtrl (30.28) is set to alarm.^[1][2]

Drive response: Alarm level 4: indication only; monitored always

Likely causes

• DCSLink cable, termination or node ID fault
• Mixed firmware versions (3.6 and lower with 3.7 and higher)

First checks, in this order

1. Check FirmwareVer (4.01) on all drives.
2. Check ComLossCtrl (30.28) and the mailbox settings in group 94.
3. Check the DCSLink cables, termination and DCSLinkNodeID (94.01).

A115: TachoRange (Selected motor, tacho range)

What it means: If it stays longer than 10 s, the analog tacho input is overflowing. If it shows for 10 s and clears, M1OvrSpeed (30.16) or M2OvrSpeed (49.21) was changed and a new tacho fine tuning is needed.^[1][2][3]

Also on: DCS550 (same code and name)

Drive response: Alarm level 4: indication only; monitored always

Likely causes

• Tacho wired to the wrong voltage range terminal
• Overspeed level changed after tacho fine tuning

First checks, in this order

1. Check the tacho connections on X3:1 to X3:4 of SDCS-CON-4.
2. Repeat the tacho fine tuning with ServiceMode (99.06) = TachFineTune.

A116: BrakeLongFalling (Selected motor, mechanical brake)

What it means: The acknowledge that the mechanical brake has closed (applied) is missing.^[1][2]

Drive response: Alarm level 4: indication only; monitored always

Likely causes

• Brake slow to close or not closing
• Brake acknowledge wiring fault

First checks, in this order

1. Check M1BrakeAckSel (42.02), BrakeFaultFunc (42.06) and M1BrakeLongTime (42.12).
2. Check the brake, its cabling and the digital inputs and outputs used (group 14).

A120: OverVoltProt (Overvoltage protection active)

What it means: The DCF806 overvoltage protection unit is active and the converter is blocked, with firing held at 150 degrees and single pulses.^[1][2]

Drive response: Alarm level 3: firing angle set to 150 degrees, single firing pulses, drive restarts when the condition clears; monitored always

Likely causes

• Overvoltage in the field circuit triggered the DCF806
• Field converter cable or connection fault
• Signal polarity wrong

First checks, in this order

1. Check OvrVoltProt (10.13) and invert the signal in group 10 if needed.
2. Check the field converter cables and connections.

A122: MechBrake (Selected motor, mechanical brake)

What it means: The brake applied (closed) acknowledge is missing, or during torque proving the actual torque did not reach StrtTorqRef (42.08); BrakeFaultFunc (42.06) set this to alarm.^[1][2]

Drive response: Alarm level 4: indication only; monitored always

Likely causes

• Brake or brake acknowledge wiring fault
• Torque proving reference too high or motor unable to reach it

First checks, in this order

1. Check BrakeFaultFunc (42.06), M1StrtTorqRefSel (42.07) and M2StrtTorqRefSel (49.44).
2. Check the brake, its cabling and the digital inputs and outputs used (group 14).

A124: SpeedScale (Speed scaling out of range)

What it means: The speed scaling parameters give a value out of range. Firing is held at 150 degrees with single pulses until it is corrected.^[1][2][3]

Also on: DCS550 (same code and name)

Drive response: Alarm level 3: firing angle set to 150 degrees, single firing pulses, drive restarts when the condition clears; monitored always

Likely causes

• Minimum, maximum, base speed or speed scaling set inconsistently

First checks, in this order

1. Find the parameters that caused it in Diagnosis (9.11).
2. Check M1SpeedMin (20.01), M1SpeedMax (20.02), M1SpeedScale (50.01) and M1BaseSpeed (99.04), and for motor 2 the values 49.03, 49.19, 49.20 and 49.22.

A129: ParRestored (Parameter restored)

What it means: At power-up the parameters in the flash were invalid (checksum fault), so all parameters were restored from the parameter backup.^[1][2][3]

Also on: DCS550 (same code and name)

Drive response: Alarm level 4: indication only; monitored always

Likely causes

• Parameter data in the flash invalid at power-up (checksum fault)
• Problem with the SDCS-CON-4 flash or the auxiliary supply at power-up

First checks, in this order

1. Check that the restored parameter values are the ones you need.
2. If it repeats, check the auxiliary power supply and the SDCS-CON-4 board.

A131: ParAdded (Parameter added)

What it means: New firmware with a different number of parameters was downloaded, and the new parameters were set to their defaults.^[1][2][3]

Also on: DCS550 (same code and name)

Drive response: Alarm level 4: indication only; shows for up to 10 s after a firmware download

Likely causes

• Firmware update

First checks, in this order

1. Find the new parameters in Diagnosis (9.11) and set them to the values you need.

A132: ParConflict (Parameter setting conflict)

What it means: A parameter setting conflicts with other parameters.^[1][2][3]

Also on: DCS550 (same code and name)

Drive response: Alarm level 4: indication only; monitored always

Likely causes

• Two or more parameters set in a combination the firmware does not allow

First checks, in this order

1. Find the parameters that caused it in Diagnosis (9.11) and correct them.

A140: IllgFieldBus (Illegal fieldbus settings)

What it means: The fieldbus parameters in group 51 do not match the fieldbus adapter, or the adapter has not been selected.^[1][2][3]

Also on: DCS550 (same code and name)

Drive response: Alarm level 4: indication only; monitored always

Likely causes

• Group 51 settings wrong for the fitted adapter
• Fieldbus adapter not selected or not configured

First checks, in this order

1. Check the settings in group 51.
2. Check the configuration of the fieldbus adapter and CommModule (98.02).

A141: COM8FwVer (SDCS-COM-8 firmware version conflict)

What it means: The SDCS-CON-4 firmware and the SDCS-COM-8 firmware are not a valid combination.^[1]

Drive response: Alarm level 4: indication only; monitored always

Likely causes

• SDCS-CON-4 and SDCS-COM-8 firmware versions that do not belong together

First checks, in this order

1. Compare FirmwareVer (4.01) and Com8SwVersion (4.11) with the valid combinations in the release notes.

A142: MemCardMiss (Memory Card missing)

What it means: An application is loaded in the drive, but the Memory Card that belongs to it is not found.^[1]

Drive response: Alarm level 1: indication; after a stop the main contactor cannot close again until it clears; active directly after the electronics are switched on

Likely causes

• Memory Card missing or not properly plugged into X20 on the SDCS-CON-4
• ParApplSave (16.06) still expects a Memory Card although none is used

First checks, in this order

1. Check that the Memory Card is properly plugged into the SDCS-CON-4 (X20).
2. Switch the electronics off, insert the proper Memory Card and switch them on again.
3. Check ParApplSave (16.06).
4. If no Memory Card is used, set ParApplSave (16.06) = DisableAppl.

A143: MemCardFail (Memory Card failure)

What it means: Checksum failure, or the wrong Memory Card.^[1]

Drive response: Alarm level 1: indication; after a stop the main contactor cannot close again until it clears; active directly after the electronics are switched on

Likely causes

• Faulty Memory Card
• A Memory Card that is not a proper ABB Memory Card

First checks, in this order

1. Check the Memory Card.
2. Check that a proper ABB Memory Card is used.
3. Check ParApplSave (16.06).