Fanuc alarm 454: SYSTEM OVERHEAT (CONTROL UNIT) AND SHUTDOWN
30i/31i/32i system alarm · Fanuc 30i/31i/32i-B
What it means
Temperature inside the CNC control unit exceeded specification, so the system shut itself down to protect the electronics. Confirm the ambient temperature around the control is within rating and that all cooling fans are running freely before assuming board failure. Dust-clogged fans and blocked vents are the overwhelmingly common cause.
Likely causes
- Stopped or clogged cooling fan(s)
- Ambient temperature outside specification or blocked cabinet ventilation
- Main board thermal sensing fault (if environment checks out)
Triage note: Alarm 455 (FAN MOTOR STOP AND SHUTDOWN) explicitly names a failed fan.
Replacement parts
We supply the following units for this alarm — tested, warranty-backed:
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Control unit cooling fan (model-specific Fanuc fan unit)
unit · Common cause
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Main board (only if fans and ambient are proven good)
board · Check if others ruled out
Need the part urgently?
Send us alarm 454 with your machine details — typical RFQ turnaround is 24–48h.