Fanuc alarm SP0757: SPINDLE-1 SAFETY SPEED OVER
safety/dual-check alarm · Fanuc 30i/31i/32i-B
What it means
With the safety function enabled, the first spindle motor exceeded the safe speed defined by spindle safety parameters (Nos.4372, 4438, 4440, 4442) as detected in the CNC/spindle cross-check. Safe spindle speed monitoring permits tool changes and workpiece handling with the door unlocked; an overspeed trip immediately stops the spindle and removes power. Verify commanded gearing and that the spindle decelerates below the safe threshold before door unlock.
Likely causes
- Spindle running above the programmed safe speed during door-open operation
- Incorrect safe-speed parameter values for the gear range in use
- PMC releasing the door before spindle slowdown completes
Triage note: Second-spindle counterpart is SP0787; the spindle amplifier itself shows indication 69 for the same condition.
Need the part urgently?
Send us alarm SP0757 with your machine details — typical RFQ turnaround is 24–48h.