Schneider Electric VFD fault codes

Common causes

• Acceleration too fast or heavy load
• Motor or cable fault
• Damaged power stage

What to check

• Disconnect the motor cable and run the drive without load: if the fault stays, the drive itself is faulty
• Megger the motor and cable for insulation or phase-to-phase faults
• Increase acceleration/deceleration time; check for mechanical jams

Common causes

• Short circuit or earth fault on the output
• Failed IGBT

What to check

• Megger the motor and cable to earth
• Check for water or dust in the motor terminal box
• If insulation is fine, the output IGBT or current sensor may be faulty

Common causes

• Deceleration too fast
• Regenerative load
• No braking resistor

What to check

• Increase the deceleration time or enable the stall/overvoltage prevention function
• Check the braking resistor and braking transistor (if fitted)
• Measure the supply voltage – it should be within the drive's rating

Common causes

• Low supply voltage
• Faulty pre-charge

What to check

• Measure all three input phases under load
• Check input fuses, contactor and loose terminals
• If the supply is fine, check the DC bus capacitors and pre-charge circuit

Common causes

• Fan failure
• High ambient temperature

What to check

• Clean the heatsink and check that the cooling fan runs
• Check the panel temperature and ventilation
• Reduce the load or carrier frequency

Common causes

• Motor overloaded
• Wrong thermal current setting

What to check

• Check the motor thermal current parameter and the load

Common causes

• Missing supply phase
• Blown fuse

What to check

• Measure all three input phases under load
• Check input fuses, contactor and loose terminals
• If the supply is fine, check the DC bus capacitors and pre-charge circuit

Common causes

• Broken motor cable
• Motor contactor open

What to check

• Check motor cable and contactor

Common causes

• Control or power board fault

What to check

• Power off and on; repeating INF codes need board repair