430

Navigate to DIAGNOSIS > SERVO screen and monitor parameter 300 (Servo Load Meter) for the affected axis during typical machine operation. Values consistently above 80% indicate excessive loading.

Check parameter 2020-2023 (Load Inertia Ratio) to verify motor sizing is adequate. If ratio exceeds 1:30 for standard motors or 1:50 for high inertia motors, mechanical load may be too high.

Inspect mechanical components on the affected axis for binding, excessive friction, ballscrew damage, or worn way surfaces. Manually move the axis with servo OFF to feel for resistance or rough spots.

Always enable EMERGENCY STOP before manually moving axes with servos disabled

Review cycle time and reduce rapid feed rates (parameters 1420-1423) or optimize toolpath to reduce continuous high-speed operation if mechanical issues are not found.

Verify motor cooling fan operation by listening for fan noise during servo-on condition. For motors with separate fan power supply, check fan voltage at amplifier connector (typically 24VDC or 200VAC depending on motor model).

Inspect motor cooling fins and ventilation ports for debris accumulation. Clean using compressed air (maximum 30 PSI) with machine powered off, ensuring coolant, chips, and oil residue are removed.

Wear appropriate PPE including safety glasses when using compressed air

Check ambient temperature in electrical cabinet and around motor. Navigate to DIAGNOSIS > SERVO and check parameter 401-404 (Amplifier Temperature Monitor). Cabinet temperature should not exceed 40-45°C.

Verify cabinet cooling fans and heat exchangers are functioning. Replace motor cooling fan if not operational. For αi-series motors, fan part number is typically found on motor nameplate.

Navigate to DIAGNOSIS > SERVO screen and check parameter 411-414 (Motor Temperature Monitor). Compare reading with actual motor temperature by feel after allowing adequate cool-down. Excessive reading (>90°C) when motor is cool indicates thermistor circuit fault.

Inspect motor feedback cable (encoder cable) for physical damage, tight bend radius, or wear at cable gland entry points. Check connector pins at both motor and amplifier ends for corrosion or bent pins.

Disconnect amplifier power before removing or inspecting feedback cable connectors

Measure thermistor resistance at motor connector with cable disconnected from amplifier. At room temperature (25°C), resistance should be approximately 300-500Ω for most Fanuc motors. Refer to motor parameter manual for specific values.

If thermistor readings are erratic or out of specification, replace motor feedback cable. If problem persists, motor thermistor may be faulty requiring motor repair or replacement.