Liaobu Schneider frequency converter maintenance hotline

Liaobu Schneider 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!

Liaobu Schneider frequency converter maintenance hotline

Analysis of Common Fault Cases and Maintenance Methods for Schneider Inverter

1、 Undervoltage fault (UV/LU alarm)

‌Case performance‌：

• When the DC bus voltage is lower than the rated threshold (triggered when the input voltage of the ATV310 series is less than 325V), the panel displays the "Under Voltage" or "--11" code13.
  ‌Cause investigation‌：

1. ‌Power side issuesCheck if the three-phase input voltage fluctuates beyond 380V ± 15%, and inspect for poor circuit breaker contact or broken power supply cables14；

2. ‌Capacitor agingLong term undervoltage leads to capacity degradation of electrolytic capacitors, which can be measured by a multimeter for capacitor charging and discharging performance19；

3. ‌Motherboard detection abnormalityIf the DC bus voltage does not match the displayed value on the panel, the motherboard detection circuit needs to be replaced4.
   ‌Repair Method‌：

• Reset parameters (such as H03 set to 1 initialization parameter) and increase carrier frequency (F26 adjustment)4Replace damaged capacitors or repair poor contact points in the power supply19.

2、 INF malfunction (button failure)

‌Case performance‌：

• The ATV31H series panel displays an "INF" alarm, and the membrane buttons are malfunctioning, often due to moisture or long-term use causing circuit breaks2.
  ‌Maintenance steps‌：

1. Pull out the thin film plug of the display board and confirm the position of the circuit breaker (such as the disconnection of pins 2 and 7);

2. Short circuit the 2 and 7 pins of the CN11 socket directly through the PCB surface without the need to replace the film panel2.

3、 OLF overload fault

‌Case performance‌：

• ATV31 series reports "OLF" during operation, which may be accompanied by fan stoppage or abnormal heat dissipation711.
  ‌Reasons and Handling‌：

1. ‌Fan failureCheck the 24V fan power supply, replace the damaged Q81 (can be replaced with 9012) or repair the drive circuit7；

2. ‌Parameter SettingsAdjust the parameters of "Cold Stator Resistance" (rSC) and "Motor Thermal Current" (ItH) to match the actual load11；

3. ‌Environmental optimizationClean the dust in the heat dissipation channel to ensure that the ventilation conditions meet the standards711.

4、 OCF overcurrent fault

‌Case performance‌：

• During acceleration or operation, an "OC" code may be reported, possibly due to output short circuit, IGBT module damage, or cable length46.
  ‌solution‌：

1. ‌Hardware inspectionTest the diode characteristics of IGBT modules and investigate whether the motor cable joints are loose or the insulation is damaged9；

2. ‌parameter adjustmentExtend acceleration and deceleration time, reduce torque increase value; If the small capacity frequency converter reports OC3, the short-circuit point of the 24V fan needs to be repaired46.

5、 No output fault

‌Case Analysis‌：

• ATV71HD75N4Z has no output voltage during operation, and the front stage circuit breaker trips8.
  ‌troubleshooting direction‌：

1. ‌electrolytic capacitorCheck if there is any leakage or capacity decrease in the busbar capacitor;

2. ‌driver moduleCheck if the inverter module and drive card signals are normal, and replace damaged drive components8；

3. ‌Contactor statusConfirm the suction status of the internal contactor and the reliability of the auxiliary contact contact9.

6、 Other common faults

1. ‌U1 overvoltage alarmCheck the insulation and DC capacitance status of the cable, and adjust the self-tuning parameters of the high inertia load if necessary46；

2. ‌Er7 self-tuning abnormalityCheck the resistance of the charging resistor and the engagement of the contactor, and replace damaged components4；

3. ‌SC short circuit alarmTroubleshooting motor winding short circuit or internal circuit grounding fault of frequency converter6.

Maintenance precautions

• ‌Parameter BackupRecord the original machine parameters before maintenance to avoid configuration loss after initialization;

• ‌Environmental protectionRegularly clean internal dust, improve equipment ventilation and moisture resistance conditions27；

• ‌Professional SupportFor complex faults (such as motherboard damage), it is recommended to contact an authorized service center for handling

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