Fanuc AC Axis Unit Alarms and Error Codes

Fanuc AC Axis Unit Alarms. These alarm and error codes cover the A06B-6050 series.

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TypeIndicationsDescription of Alarm/Error
Overload.Contacts signal comes out at connector CN1.Should the temperature of the radiation fin of the unit exceds the set value to operate the thermostat. Or if the thermostat of power transformer operates. Or if the thermostat of motor operates, this overload alarm is generated.
Velocity feedback disconnection detection.Light-emitting diode (LED) TG lights. If the feedback cable is disconnected, TG lamp lights.  If a motor does not make a speedy start because of extremely large motor torque. The motor is stopped by dynamic braking with this alarm lamp lit.
No use breaker.On button of NFB is protruded.Should an abnormal current exceeding the operating current of no fuse breaker flows. NFB operates, causing the motor to be stopped by dynamic braking.
High voltage alarm.LED HV lights. If the DC voltage of the main power supply is abnormally high. The motor is stopped by dynamic braking with HV lamp lit.
 Low voltage alarm.LED LV lights.Should the control voltage be abnormally low, or if the fuse for +5V on the PCB has blown out. The motor is stopped by dynamic braking with LV lamp lit.
Circuit Fault detection.LED HC lights.

LED DC lights.

If abnormal current flows to the main circuit, the motor is stopped by dynamic braking with LV lamp lit.

Should the regenerative discharge circuit becomes defective, the motor is stopped by dynamic braking with DC lamp lit. If the acceleration/deceleration rate is too high, DC Lights.

Overcurrent alarm.LEC OVC lights. If current exceeding specified value is continuously applied longer than a certain time The motor is stopped by dynamic barking with OVC lamp lit.