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Yaskawa CACR-120-PD1VDS01 Servopack Hauptansicht
22.01.2026 by Viktor Siebert
Repair of a Yaskawa CACR-120-PD1VDS01 Servopack with fan error

The servopack CACR-120-PD1VDS01 was received with Alarm A.7A0(fan error). According to the customer, the fault initially occurred sporadically and later led to a permanent axis shutdown. Externally, the unit showed no heavy contamination, which initially made the fault appear uncritical.

After opening the unit, the cooling fan was electrically tested. It was found that the fan itself was defective and no longer started properly. The defect was not mechanical but caused by an internal electrical failure of the fan.

During further analysis, it became apparent that the defective fan had caused a short circuit in the fan control circuit. This short circuit affected the electronics over an extended period of time. As a result of this continuous load, individual circuit sections on the power board were overloaded, particularly in the area responsible for fan supply and monitoring.

This type of failure progression is typical for unplanned fan failures. Initially, only the fan alarm is triggered. Cooling performance decreases without an immediate shutdown. During this phase, the servopack continues to operate with reduced thermal reserves. Components around the power stage and auxiliary power supply are continuously exposed to thermal and electrical stress. In this condition, gradual secondary damage occurs that is not immediately visible.

The faulty circuit was localized and repaired. The defective fan was replaced. Subsequently, the servopack was fully overhauled as a preventive measure. All components known to be affected by aging and thermal stress were inspected and replaced as a precaution. The objective was not only to eliminate the immediate fault but to restore long-term operational reliability.

After completion of the repair, the unit was tested on the test bench. Functional testing under load conditions was carried out, including temperature monitoring and continuous operation. The servopack then operated stably and within the specified limits.

This repair case clearly demonstrates that a fan alarm must not be treated as an isolated minor issue. A failed fan can lead to secondary damage to the power electronics within a short time. Regular cleaning, scheduled fan replacement, and timely overhaul reliably prevent such failure chains.

Information about the mentioned Servopack: Yaskawa Servopack CACR-120-PD1VDS01

Further details on our Yaskawa repairs can be found here: Yaskawa Sigma V Repair

📞 Feel free to contact us if you have any questions regarding your Yaskawa drive technology. Our team will be happy to assist you.


Technical Specifications

ParameterValue
ManufacturerYaskawa Electric Corporation
Device typeAC servopack
ModelCACR-120-PD1VDS01
Protection classIP10
AC inputSingle-phase 200–230 V AC
Line frequency50/60 Hz
Input current16 A
Motor outputThree-phase 0–230 V AC
Output current11.6 A
Output frequency0–400 Hz
Rated power1.5 kW
CoolingActive fan cooling
Ambient temperature0–55 °C
Country of manufactureJapan

Installation Environment and Typical Applications

AreaDescription
CNC machinesFeed axes, positioning axes
Machine toolsMilling machines, lathes
Automation systemsHandling and feeding axes
Special machineryAxis control with analog command signals

The CACR series is frequently used in older CNC machines where analog servo control is applied. The device is comparable to later Yaskawa servopacks and shows functional similarities to the SGDV Sigma V series, particularly regarding protection functions and alarm behavior.


Functional Description

The servopack controls an AC servomotor via a pulse-width-modulated power stage. Speed and torque regulation is handled by internal control loops. Protection functions monitor current, voltage, temperature, and correct fan operation.

The cooling fan is a safety-relevant component. It ensures adequate cooling of the power electronics. If a malfunction is detected, the corresponding alarm code is triggered to prevent thermal damage.

Alarm Messages and Troubleshooting Yaskawa CACR-120-PD1VDS01

AlarmDesignationMeaning / CauseAction
A.020Error 1 Parameter ChecksumParameter data in the SERVOPACK is incorrect, for example after a voltage drop or too many parameter changesCheck supply voltage, initialize parameters with Fn005, set them again, replace SERVOPACK if necessary
A.021Error 1 Parameter FormatParameter data is incompatible or faultyCheck software version and parameters, load matching parameter set, replace SERVOPACK if necessary
A.022Error 1 System ChecksumFaulty system data in the SERVOPACKCheck power supply, replace SERVOPACK if necessary
A.030Input Voltage Detection ErrorDetection data for mains input is incorrectCheck SERVOPACK, replace if necessary
A.040Parameter Setting Error 1Parameter is outside the valid setting rangeCheck parameters and set valid values
A.041Encoder Output Pulse Setting ErrorPn212 is outside the valid rangeCorrect Pn212
A.042Parameter Combination ErrorParameter combination exceeds permissible rangeCheck and adjust electronic gear, jog operation, or tuning parameters
A.044Parameter Setting Error with Disabled External Encoder / Direct Measurement System ControlOption module and parameter settings do not matchMatch Pn002.3 and option module setting
A.050Combination ErrorSERVOPACK and servomotor power ratings do not matchCheck device combination, select matching motor or SERVOPACK
A.051Unsupported Device AlarmUnsupported encoder, converter, or device connectedUse the correct system combination
A.0b0Alarm Servo ON Command WithdrawnServo ON was withdrawn incorrectly after auxiliary functionPower cycle and reset software
A.100Overcurrent or Heatsink OverheatOvercurrent through IGBT or heatsink overtemperatureCheck wiring, short circuit, ground fault, braking resistor, load, and cooling, replace SERVOPACK if necessary
A.300Regeneration FaultFault in braking circuit or braking resistorCheck braking resistor connection and parameters, check B2/B3 jumpers, replace SERVOPACK if necessary
A.320Regenerative OverloadRegenerative energy exceeds braking resistor capacityCheck supply, braking resistor, load, and operating conditions
A.330Power Supply Wiring FaultAC/DC input set incorrectly or mains wiring incorrectCheck supply type, wiring, and braking resistor
A.400OvervoltageDC bus voltage too highCheck mains voltage, surges, braking resistor, inertia, and deceleration
A.410UndervoltageDC bus voltage too lowCheck mains voltage, voltage dips, power interruption, and fuse
A.450Main Circuit Overvoltage CapacitorMain circuit capacitor impaired or defectiveReplace SERVOPACK
A.510OverspeedMotor speed exceeds maximum limitCheck motor wiring, command value, gain, and operating conditions
A.511Overspeed Encoder Output Pulse RateEncoder output frequency is too highReduce Pn212, reduce motor speed
A.520Vibration AlarmUnusual vibration detected at motor speedReduce speed, reduce gain, adjust inertia
A.521Autotuning AlarmVibration detected during tuningCheck and adjust load level and tuning settings
A.710Overload High LoadMotor was heavily overloaded for a short periodCheck wiring, load, motion profile, and mechanics
A.720Overload Low LoadMotor was continuously overloadedChange load and operating conditions, use larger motor if necessary
A.730 / A.731Dynamic Brake OverloadRotational energy exceeds dynamic brake capacityReduce speed, inertia, and number of braking operations
A.740Inrush Current Limiting Resistor OverloadMain power was switched on and off too frequentlyReduce switching frequency
A.7A0Heatsink OverheatSERVOPACK heatsink above 100 °CCheck ambient temperature, load, regenerative energy, mounting position, and cooling
A.7ABSERVOPACK Fan Not RunningInternal fan failed or blockedRemove foreign objects, replace SERVOPACK if necessary
A.810Encoder Backup ErrorEncoder position data was lostCheck battery and encoder power supply, reinitialize encoder
A.820Encoder Checksum ErrorEncoder memory checksum is incorrectReinitialize encoder, replace motor if necessary
A.830Absolute Encoder Battery ErrorBattery voltage too lowCheck battery connection, replace battery
A.840Encoder Data ErrorIncorrect data in encoderCheck wiring, EMC, and encoder
A.850Encoder OverspeedEncoder was rotating too fast during power onReduce motor speed during power on, check encoder
A.860Encoder OverheatEncoder internal temperature too highCheck ambient conditions, load, and encoder condition
A.8A0External Encoder ErrorExternal encoder faultyCheck or replace external encoder
A.8A1External Encoder Module ErrorSerial converter faultyReplace serial converter
A.8A2External Encoder Sensor ErrorFault in external encoderReplace encoder
A.8A3External Encoder Position ErrorPosition data from external encoder faultyCheck external encoder
A.b10Speed Reference A/D ErrorA/D converter for speed reference faultyClear alarm, restart, replace SERVOPACK if necessary
A.b11Speed Reference A/D Data ErrorA/D converter data for speed reference faultyClear alarm, restart, replace SERVOPACK if necessary
A.b20Torque Reference Input Read ErrorA/D converter for torque reference faultyClear alarm, restart, replace SERVOPACK if necessary
A.b31Current Detection Error 1Current detection circuit phase U defectiveCheck or replace SERVOPACK
A.b32Current Detection Error 2Current detection circuit phase V defectiveCheck or replace SERVOPACK
A.b33Current Detection Error 3Current detection circuit defectiveCheck servomotor wiring, replace SERVOPACK if necessary
A.bF0 to A.bF4System Alarm 0 to 4Internal program or system fault in SERVOPACKPower cycle, replace SERVOPACK if necessary
A.C10Loss of Servomotor Phase DetectedMotor out of control, U/V/W incorrect or encoder faultCheck motor wiring and encoder
A.C80Absolute Encoder Clear Error / Multiturn Limit Setting ErrorFault in absolute encoder or multiturn settingCheck encoder and settings
A.C90Encoder Connection ErrorCommunication between SERVOPACK and encoder not possibleCheck connector, cable, impedance, ambient conditions, and EMC
A.C91Encoder Connection Position Data ErrorError while calculating encoder position dataCheck cable, routing, shielding, and grounding
A.C92Encoder Connection Timer ErrorCommunication timer between encoder and SERVOPACK faultyCheck EMC, vibration, encoder, and SERVOPACK
A.CA0Encoder Parameter ErrorEncoder parameters faultyCheck motor, encoder, or SERVOPACK
A.Cb0Encoder Feedback ErrorCommunication content with encoder faultyCheck cable, shielding, length, grounding, vibration, and encoder
A.CC0Multiturn Limit MismatchEncoder and SERVOPACK have different multiturn limitsMatch Pn205 and encoder data
A.d00Position Error OverflowPosition error exceeds Pn520 thresholdCheck U/V/W, command pulse frequency, acceleration, and parameters
A.d01Position Error Overflow Alarm at Servo ONPosition error too large at switching onClear position error, check Pn526
A.d02Position Error Overflow Alarm Due to Speed Limit at Servo ONResidual position error plus command pulses cause overflowClear position error, check Pn520/Pn529
A.Eb1Safety Function Input Signal Timing ErrorTime interval between /HWBB1 and /HWBB2 too largeCheck input signals, wiring, and safety circuit
A.F10Open Phase in Power LineOne phase R/S/T too low for longer than 1 secondCheck mains wiring, phase balance, and input supply
CPF00Digital Operator Communication Error 1Communication between digital operator and SERVOPACK faultyCheck connector, cable, and EMC
CPF01Digital Operator Communication Error 2Fault in digital operator or SERVOPACKReconnect digital operator, replace if necessary

Main Components

AssemblyFunctionInspection notes
Power boardMotor controlCheck for thermal damage
Fan assemblyCoolingReplace at regular intervals
Control boardRegulation and monitoringMeasure supply voltages
Heat sinkHeat dissipationCheck for contamination
ConnectorsSignal and power pathsCheck contact condition

Preventive Measures for Operation

MeasureRecommendation
CleaningRegularly, depending on environment
Fan replacementPreventive, before failure
Visual inspectionHeat sinks, connectors, cables
OverhaulTime-based instead of damage-based
Temperature monitoringUse as early warning

Conclusion

A fan failure is not a minor alarm. This repair case shows that a defective fan can lead to gradual overload of the power electronics. Preventive maintenance and timely overhaul reliably avoid unplanned downtime and secondary damage.


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