
3.TROUBLESHOOTING AND ACTION TROUBLESHOOTING B-65285EN/03
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3.4.25 Alarm Codes 52 and 53
The synchronization signal (ITP) in communication data transferred to
and from the CNC stopped.
Troubleshooting when this alarm is issued
(a) The SPM is faulty.
Replace the SPM or SPM control printed circuit board.
(b) The CNC is faulty.
Replace the board or module related to the serial spindle.
3.4.26 Alarm Code 54
A large current flowing in the motor for a long time was detected.
Troubleshoot as in the case of alarm code 29.
3.4.27 Alarm Code 55
In spindle switching control or output switching control, a mismatch
between the switching request signal (SPSL or RSL) and the power
lead state check signal (MCFN, MFNHG, RCH, or RCHHG) continues
during motor activation.
Troubleshooting when this alarm is issued
(a) The magnetic contactor (switch unit) for power lead switching is
faulty.
If the contact is inoperative, check the power supply of the
magnetic contactor. If the magnetic contactor is still inoperative,
replace the magnetic contactor.
(b) The I/O unit or wiring for checking the contact of the magnetic
contactor is faulty.
If a defect is found in the I/O unit or wiring, replace the I/O unit or
wiring.
(c) The sequence (ladder) is incorrect.
Modify the sequence so that switching is not performed during
activation. For details of the signals, refer to "FANUC SERVO
AMPLIFIER αi series Descriptions (B-65282EN)."
3.4.28 Alarm Code 56
The cooling fan for the control circuit section has stopped.
(a) Poor installation of the control printed-circuit board
Be sure to push the faceplate as far as it will go. (This alarm may
be displayed if one of the connectors for connection between the
control printed-circuit board and power printed-circuit board is
detached.)
(b) Replace the SPM or its internal cooling fan.