FANUC Alarm SRVO-023 — SERVO Stop error excess

Description

A excessive servo positional error occurred when the motor stopped.

Remedy

1. Check whether the applied load exceeds the rating. If so, reduce the applied load. If an excessive load is applied, the torque required for acceleration, deceleration, and so forth exceeds the maximum available torque of the motor. Therefore, it might prove impossible to correctly respond to an issued command, resulting in the output of this alarm. 2. Check each interphase voltage of the three-phase voltage (200 VAC) applied to the servo amplifier. If the voltage is found to be 170 VAC or below, check the input power supply voltage. A sub-standard voltage, applied to a servo amplifier, results in a lower-than-normal torque. Therefore, it might prove impossible to correctly respond to an issued command, thus resulting in the output of this alarm. Check phase-to-phase voltage across the three pins of connector CRM38A or CRM38B of the servo amplifier. 3. If the input power supply voltage is found to be 170 VAC or higher, replace the servo amplifier. 4. Check the motor power cables (RM1, RM2, RM3) for damage, to cable or pins, and that the connector is securely connected. WARNING: By completing the next step you will be altering the positional reference for the robot since you are replacing hardware. You must slowly verify all positional data and touch-up any paths or points that have changed. Otherwise, you could injure personnel or damage equipment. 5. Replace the motor, and remaster the robot.

Field diagnosis

With the robot stopped, the servo position error exceeds the threshold: the axis is not holding its position. Brake not released, power or brake cable broken, overload, external force, low voltage or incorrectly set two-brake option.

What to check

• Listen for the brake click at startup; without a click, check the continuity of the brake line (robot connection cable and internal cable).
• Check the cycle rate and load, external force, the power and brake connectors, the supply voltage, and the two-brake option setting.
• Note: On J3 of an older robot, this code on the first motion of the morning is often a stuck brake.

Related codes

Same hardware involved