Battery zero alarm

Battery Zero Alarm

Fanuc · A20B-2101-0390 αi series AC Servo Motor and Spindle

What does Battery zero alarm mean?

This alarm indicates that the absolute position data for the Pulsecoder may be lost or displaced, often occurring if the sensor head is moved after the initial power-on and conduction state, or if the battery is depleted/disconnected.

Repair Steps

  1. 1

    Detach cable K1 from connector OUT1 of the sensor circuit.

  2. 2

    Connect connector IN2 to connector OUT1 on the sensor circuit.

  3. 3

    Maintain this connection for 10 seconds.

  4. 4

    Connect all other sensor cables correctly.

  5. 5

    Reconnect cable K1 to OUT1.

  6. 6

    Perform reference position return operation after ensuring the alarm is issued.

Browse all codes in this manual (29)
Verified technical data. Last updated: March 2026
Source: Fanuc A20B-2101-0390 αi series AC Servo Motor and Spindle