
7. TROUBLESHOOTING
B–63505EN/02
278
Spindle speed changes abnormally due to load.
Confirm the following
parameter :
Check whether spindle speed is constant by view
of the speed meter on CRT.
Constant ?
Heavy cutting?
Is a heavy cutting being per-
formed ? Confirm spindle load
on CRT.
Reduce cutting condition
PRM 4911
PRM 4912
PRM 4913
PRM 4914
Doesn’t the cutting tool worn ?
Worn ?
Spindle servo unit is faulty
Spindle motor is faulty
Replace tool
YES
NO
YES
NO
YES
NO
PRM 4911 : A ratio of spindle speed at which actual spindle speed is
regarded as arrived at a command spindle speed.
PRM 4912 : Spindle speed fluctuation ratio up to which the spindle
speed fluctuation detection alarm is not issued.
PRM 4913 : Spindle speed fluctuation that is not regarded as the spindle
speed fluctuation alarm.
PRM 4914 : Time when a spindle speed changed to when spindle speed
fluctuation detection is started.
7.23
ALARM 704
(SPINDLE SPEED
FLUCTUATION
DETECTION ALARM)
Remedies
Remedies