Fuji FRENIC Mini inverter troubleshooting

2.3 Motor Reverse Rotation

Possible reasons:

The output phase sequence U, V, W does not correspond to the motor terminals.

If terminal operation is used, the wiring between FWD and REV will be reversed.

If running on the panel, F02 is set to 3 (reverse fixed direction).

handle:

Swap any two-phase output lines, or adjust parameter F02 to 2 (fixed forward rotation).

Check the default values (98 and 99) for E98 (FWD function) and E99 (REV function).

2.4 Motor speed fluctuation, vibration or abnormal noise

Possible reasons:

The carrier frequency (F26) is too low (≤ 2 kHz), resulting in high electromagnetic noise.

Mechanical resonance (the natural frequency of the load coincides with the output frequency).

Excessive torque boost (F09) leads to excessive excitation.

The PID control parameters are not appropriate.

handle:

Increase F26 (recommended 4-8 kHz) to reduce motor noise.

Use the jump frequency function (C01~C04) to avoid resonance points.

Gradually reduce F09 (default value reference parameter table) and observe whether the current decreases.

If PID (J01=1 or 2) is enabled, readjust the proportional gain J03 (usually 0.1-1.0) and integration time J04 (5-20 seconds).

Common alarm codes and countermeasures (must read on site)

FRENIC Mini uses 4-digit 7-segment LED to display alarm codes. The following are the most frequently occurring codes and their handling methods.

3.1 0c1/0c2/0c3- Instantaneous Overcurrent

Meaning: The output current exceeds the rated value of the frequency converter. 0c1 occurs during acceleration, 0c2 during deceleration, and 0c3 during constant speed operation.

Common reasons:

Output side short circuit or grounding (motor cable damage, water ingress into terminal box).

The acceleration time (F07) is too short, resulting in excessive starting current.

The torque boost (F09) is set too high.

Motor stalling or mechanical brake not open.

Processing procedure:

Disconnect the output line of the frequency converter and measure whether the resistance between U-V, V-W, and W-U is normal (motor winding resistance value). If the resistance is zero or extremely small, there is a short circuit.

Perform insulation testing on the output cable using a 500V megohmmeter. If the ground resistance is less than 5M Ω, the cable needs to be replaced.

Extend the acceleration time (increase F07 to 10-20 seconds).

Gradually reduce F09 (e.g. from 8% to 4%) and observe if there is any improvement.

If the mechanical brake is not released, check the brake control circuit.

3.2 0u1/0u2/0u3- Overvoltage

Meaning: The DC bus voltage exceeds the protection value (200V series>400V, 400V series>800V).

Common reasons:

The deceleration time (F08) is too short, and there is too much regenerative energy feedback from the motor.

The power supply voltage is too high (exceeding the rated value by 10%).

The braking resistor is not connected or the resistance is too high.

handle:

Extend the deceleration time (set F08 to 10-30 seconds).

Enable automatic deceleration (Anti regenerative control, H69=2 or 4).

For situations where quick parking is required, install brake resistors and correctly set F50 and F51 parameters.

Measure the input voltage. If it exceeds 264V (200V series) or 528V (400V series), adjust the tap of the power side transformer.

3.3 Lu - Undervoltage

Meaning: The DC bus voltage is lower than the detection level (200V series<200V, 400V series<400V).

Common reasons:

Instantaneous power outage or low power supply voltage.

The power capacity is insufficient, and the voltage drops when the large motor starts.

The main circuit contactor (MC) has poor contacts.

handle:

If occasionally caused by a momentary power outage, F14 can be set to 4 or 5 (instantaneous power outage restart) to automatically restart after the power is restored.

Measure the input voltage, and if it is lower than the rated voltage by more than 15%, improve the power supply.

Check whether the MCCB and MC wiring terminals are overheated or oxidized, and replace them if necessary.

3.4 0l1/0l2- Motor overload

Meaning: Electronic thermal relay action, motor overload for a long time.

handle:

Check if the load is too heavy (the ammeter monitors whether the output current exceeds the rated current of the motor).

Confirm that parameter F11 (overload detection level) is set to the motor nameplate current value (unit: A).

If the motor is a frequency conversion dedicated motor with an independent fan, set F10 to 2 (constant cooling effect).

Reduce load or install external heat dissipation.

3.5 0h1- Overheating of heat sink

Meaning: IGBT heat sink temperature exceeds 90 ° C.

Reason:

The ambient temperature is too high (>50 ° C).

Cooling fan malfunction or blockage.

The high carrier frequency F26 (>12kHz) results in significant losses.

handle:

Clean the dust from the fan and heat sink.

Check if the fan is rotating (FRN0010C2S and above models have fans). If it is not rotating, replace the fan (please consult Fuji for the model).

Reduce F26 to below 4kHz.

Improve cabinet ventilation and install exhaust fans if necessary.

3.6 ER2- Panel Communication Error

Meaning: Communication interruption between remote control panel and frequency converter.