FANUC Series 0i-F / 0i-F Plus alarm SP9001: MOTOR OVERHEAT
SP9001 (MOTOR OVERHEAT) on a FANUC 0i-F means the internal temperature of the spindle motor exceeded the specified level; the spindle amplifier shows alarm 01 with the red LED lit. FANUC says the motor is being used beyond its continuous rating or its cooling is not working.
Diagnose this with AI
Try Free CNC Alarm Diagnostic Upload a keypad photo, the fault history or a parameter export from your FANUC Series 0i-F / 0i-F Plus. InduQT compares the evidence and suggests the next useful checks.
When it happens
- Long heavy cuts or high-duty spindle cycles
- Frequent spindle starts and stops
- Any time if the motor fan has stopped
Likely causes and checks
1Spindle motor cooling fan stopped or blocked
- Points to it
- Motor housing hot even at moderate load; no airflow at the fan.
- Check
- Check the motor fan runs and the air path is clear; FANUC’s remedy is to replace the fan if it has stopped.
2Load above the continuous rating
- Points to it
- Alarm late in heavy cycles; spindle load meter high for long periods.
- Check
- Review cutting conditions and the load meter over the cycle and reduce the load.
3High ambient or cabinet temperature
- Points to it
- More frequent in hot weather or when the enclosure is closed up.
- Check
- Check the temperature around the motor and correct the peripheral conditions.
4Thermal sensor or feedback cable fault
- Points to it
- Alarm with a cold motor, or alternating with SP9006 (thermal sensor disconnect).
- Check
- Check the feedback cable and connector; refer to the FANUC alpha i spindle motor maintenance manual (B-65285EN).
Telling it apart
- SP9009 (OVERHEAT MAIN CIRCUIT) is the amplifier heat sink, not the motor.
- SP9006 (THERMAL SENSOR DISCONNECT) means the motor temperature sensor signal is missing.
- OH0704 is a CNC-side spindle overheat detected from changes in spindle speed under load.
Evidence to collect
- Spindle amplifier display (01 with red LED)
- Spindle load over the cycle
- Motor fan condition and ambient temperature
- Whether the motor is actually hot
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