12.05.2025 by Viktor Siebert

A defective servo amplifier in a CNC machine that only started when warm – it sounds like a myth, but it happened to one of our customers. Out of fear that the unit wouldn’t start again if it cooled down, the operator kept the CNC machine running non-stop for almost a year. Weekends, holidays, nights – it was always on. The manufacturer offered no solution. Eventually, the inevitable happened: the Servopack failed during operation, blowing the fuses and shutting down the machine completely.

Only then, after tallying up the high electricity costs and production downtime, did the customer finally seek expert help.

This story is a reminder of how people often treat their health – ignoring clear signs for too long until something breaks down. The same happens with machines. The takeaway here is simple: acting early is always cheaper than letting things spiral. And one more point: not every so-called “specialist” tests repaired units properly. Some simply replace parts but skip real-world testing. Our advice: always ask how the repaired unit is tested and whether it is tested under load with a matching motor.

Final Thoughts

The customer’s decision to leave the CNC running for nearly a year to avoid a cold-start issue is understandable – yet incredibly costly. The electricity consumption, risk of fire, and eventual failure could have been avoided with a proper diagnosis early on.

This real-world story reminds us: don’t ignore the signs – in machines or in life. More importantly, ask how repairs are tested. A reputable service provider will test your repaired Servopack under load with a matching motor and verify real-world conditions before release.

If you’re dealing with issues like this or want your servo system properly tested and repaired, we’re ready to support you.

Further information such as price and delivery time for:
Yaskawa Servopack CACR-IR15SEB-P00-B04

More details about our Yaskawa repair expertise can be found here: Yaskawa CACR-IR CACR-HR Drive Reparatur bei Industrypart

Similar models we regularly repair:
CACR-IR15SEB
CACR-IR15SEBY20

Device Overview

The Yaskawa CACR-IR15SEB-P00-B04 Servopack is an AC servo amplifier used for precise motion control in industrial applications. It is part of Yaskawa’s IR series and delivers up to 1.5 kW of output power (approximately 2.0 HP). It operates on a three-phase 200–230 V AC input at 50/60 Hz and supplies up to 11.7 A to the connected AC servo motor.

The unit is designed for single-axis configurations and is commonly used in CNC machines or robots. With compact dimensions and a weight of around 5.5 kg, it fits standard control cabinets. Since this model has been officially discontinued by the manufacturer, spare parts and service are only available through independent repair specialists.

Key technical specifications:

Parameter	Value
Input Voltage	3-phase 200–230 V AC (50/60 Hz)
Input Current	10.0 A (max)
Output Voltage	3-phase 0–230 V AC
Output Current	11.7 A
Output Power	1.5 kW (≈ 2.0 HP)
Weight	approx. 5.4 kg
Use Type	Single-axis Servo Amplifier
Manufacturer	Yaskawa Electric, Japan

Application Environment and Compatible Equipment

This Servopack is typically found in CNC machines (such as milling or turning centers) and industrial robotics systems. It drives Yaskawa AC servo motors, usually from the F-series, in the 1.5 kW range.

It operates as part of a motion system controlling one machine axis. It receives command signals from the CNC or robot controller and regulates the connected servo motor accordingly. In robots, it controls a joint axis; in CNC systems, it may control an X-, Y-, or Z-axis movement.

It works with feedback devices like incremental encoders, and communicates with controllers through analog voltage or digital pulse signals. Proper thermal management is required, as the unit dissipates significant heat during operation. The device is cooled using an integrated fan or cabinet ventilation.

Functional Description

The CACR-IR15SEB Servopack performs real-time control of the connected servo motor. It uses PWM (pulse-width modulation) to generate a three-phase AC signal that matches the motion command.

Commands can come via analog ±10 V signals or pulse/direction signals. The amplifier regulates motor torque via current control, adjusts speed, and interfaces with a feedback loop using encoder signals to maintain accuracy.

Key internal functions:

• PWM control at around 46.875 kHz
• Overcurrent protection
• Dynamic brake: Applies a braking resistor to quickly stop the motor in emergencies
• Overvoltage and undervoltage detection
• Error indication via LED and serial interface
• Motor feedback via encoder (U/V phases)

The unit stops the motor safely using the dynamic brake function in case of an emergency, such as loss of main power or system alarm. After such an event, it goes into a protected state and waits for reset.

Alarms and Troubleshooting

The CACR-IR15SEB monitors various operational parameters and can display error states. Alarms are categorized into operational issues (e.g., power or feedback faults) and hardware problems.

Operational alarms:

Alarm Description	Possible Cause	Recommended Action
Overcurrent Detection	Short-circuit or blocked motor	Check motor and cables, verify load
MCCB Trip Detection	Circuit breaker triggered by overcurrent	Inspect breaker and wiring
Regenerative Problem	Brake resistor or regenerative circuit faulty	Test braking resistor and chopper circuit
Overvoltage Detection	Excessive DC bus voltage (e.g., during deceleration)	Inspect power supply and braking timing
Undervoltage Detection	Low supply voltage or power outage	Check incoming power, transformer, wiring
Ground Fault Detection	Phase-to-ground short circuit	Measure insulation resistance, replace motor
Current Offset Problem	Sensor drift or calibration loss	Recalibrate or repair control board
Current Command Disconnected	Control signal not received	Inspect input wiring, signal source
CPU Error	Main control processor failure	Power cycle; if persists, send for repair

Internal hardware alarms:

Error Code	Meaning	Possible Cause	Action
H0	CPU ROM error	Corrupted or damaged ROM	Replace ROM or mainboard
H1	CPU RAM error	RAM failure	Replace RAM or mainboard
H2/H3	Serial communication error (test)	Bus fault or test mode error	Verify internal communication
H4	Gate array failure	Logic chip fault	Replace or repair
H5	EEPROM error	Parameter storage fault	Reset EEPROM or replace
H6	Microprocessor error	4-bit microcontroller failure	Replace internal processor
H7	Current sensor U phase	Sensor or feedback fault	Replace or repair
H8	Current sensor V phase	Sensor or feedback fault	Replace or repair

Each alarm disables the amplifier (SVRDY goes off), requiring reset and potentially service intervention.