Chashan Yaskawa frequency converter maintenance hotline

Chashan Yaskawa frequency converter maintenance hotline

Dongguan Changping Juyou ElectromechanicalEquipment Maintenance Department specializes in repairing Mitsubishi servo drives, Panasonic servo drives, Yaskawa servo drives, Dongrong servo drives, Sanyo servo drives, Fuji servo drives, Delta servo drives, Omron servo drives, Fanuc servo drives, etc; MitsubishiPLCPanasonicPLCSiemensPLCOmronPLCWait; Various touch screens, frequency converters, industrial circuit boards, etc.

Provide on-site service near the company,Bringing you convenience. We have the advantages of short maintenance cycle, high repair rate, reasonable price, and no need for circuit diagrams, We have also repaired different types of circuit boards for multiple companies. Customers from outside the province can send the servo to be repaired to our company, and we will conduct testing on the day of receiving the goods and arrange for repairs as soon as possible. If the customer's machine is severely damaged and cannot be repaired, our company will not charge any fees. Welcome to consult and cooperate!

Chashan Yaskawa frequency converter maintenance hotline

Analysis and Maintenance Methods of Common Malfunctions in Yaskawa Inverter

1、 Overcurrent fault (OC/OCc)‌

‌Case phenomenon‌：

• OC malfunction reported during acceleration or deceleration process (common in A500 series), possibly accompanied by explosion noise23.

• Instantly triggered module explosion (E500 series multiple)313.

‌Cause investigation‌：

1. ‌Load issueMotor winding short circuit (phase to phase/ground short circuit) or mechanical jamming23；

2. ‌Abnormal driving circuit‌：

• Drive optocoupler (such as A3120) breakdown causing output short circuit7；

• IGBT trigger end virtual soldering or loss of negative bias voltage (prone to occur after maintenance)413；

3. ‌Improper parameter settings: Acceleration time too short or torque compensation too high26.

‌Maintenance steps‌：

1. Disconnect the load test. If OC still reports, check the inverter module and drive circuit3；

2. Measure the static voltage of the driver IC, replace damaged optocouplers or voltage regulators47；

3. After maintenance, a low-voltage test drive waveform (24V simulation) is required, and a light bulb current limiting protection is connected in series13.

2、 Overvoltage/undervoltage fault (OV/UV)‌

‌Case phenomenon‌：

• Deceleration and shutdown report OV (regenerative braking voltage exceeds the limit)69；

• Telegram UVT (undervoltage), abnormal DC bus voltage3.

‌key reason‌：

• ‌OV malfunctionFailure of braking resistor or short deceleration time (emergency stop of high inertia load)913；

• ‌UV malfunction‌：

• Damaged rectifier bridge or main contactor failure (DC bus voltage loss)6；

• Abnormal voltage detection circuit (damaged optocoupler or sampling resistor)3.

‌solution‌：

• OV: Extend deceleration time, replace brake unit/resistor (mandatory for models above 75kW)13；

• UV: Detect rectifier bridge and thyristor circuit, replace damaged voltage regulator tube6.

‌3、 No display fault‌

‌Case phenomenon‌：

• After power on, there is no display on the panel and the fan does not turn (high incidence models with poor heat dissipation)1112.

‌Fault location‌：

1. ‌Switching power supply failure‌：

• Control chip UC3844 abnormal or rear stage short circuit whistling11；

• Interturn short circuit of pulse transformer3；

2. ‌Rectification circuit issueCurrent limiting resistor burned out or rectifier bridge breakdown12.

‌Repair Method‌：

1. Measure the DC bus voltage (normal 530V) and confirm the front-end power supply11；

2. Disconnect the+5V/24V load, investigate the short circuit point, and replace the damaged switch tube or diode12.

‌4、 Overheating fault (oH)‌

‌trigger conditionInternal temperature>85 ℃58.
‌root cause‌：

• Cooling fan stops running (dust clogging bearings)5；

• Aluminum heat sink dust accumulation (common in textile factories)5；

• Insufficient installation spacing (＜ 10cm) affects air duct circulation13.

‌process flow‌：

• Clean the dust from the heat sink and replace it with a fan of the same model;

• Adjust cabinet ventilation or install auxiliary heat dissipation devices5.

‌5、 Module explosion (IGBT damage)‌

‌Typical Case‌：

• A 75kW frequency converter is used for wind turbine loads, with a deceleration time of 30 seconds (due to excessive inertia). Repeated reporting of OV and forced reset resulted in module explosion13.

‌preventive measures‌：

• Large inertia loads must be connected to an external braking unit;

• Avoid skipping protection and forcing restarts13.

‌6、 Quick search for other fault codes‌

🔧 ‌Maintenance safety regulations‌

1. ‌Replace component specificationsThe driver IC should be selected with a voltage resistance of ≥ 250V4；

2. ‌Test requirementsMeasure the balance of three-phase output voltage after maintenance (implicit DC component should be less than 5V)4；

3. ‌Capacitor maintenanceLong term idle equipment requires step charging to activate electrolytic capacitors12.