
B-65285EN/03 TROUBLESHOOTING 3.TROUBLESHOOTING AND ACTION
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3.4.7 Alarm Code 12
An excessively large current flowed into the DC link of the main
circuit.
With SPM-2.2i to SPM-11i, this alarm indicates that the power module
(IPM) of the main circuit detected an error such as an excessive load,
overcurrent.
(1) If this alarm is issued on SPM-2.2i to SPM-11i
Check alarm code 09 as well.
(2) 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.)
(3) If this alarm is issued immediately after a spindle rotation
command is specified
(a) The motor power lead is faulty.
Check for a short circuit between motor power leads and
short-circuit to ground, and replace the power lead as
required.
(b) The motor winding has an insulation failure.
If the motor is short-circuited to ground, replace the motor.
(c) The parameters specific to the motor are not set correctly.
Referring to "FANUC AC SPINDLE MOTOR αi series
Parameter Manual (B-65280EN)," check the motor-specific
parameters.
(d) The SPM is faulty.
A power element (IGBT, IPM) may be destroyed. Replace
the SPM.
(4) If this alarm is issued during spindle rotation
(a) A power element is destroyed.
A power element (IGBT, IPM) may be destroyed. Replace
the SPM.
If the amplifier setting condition is not satisfied, or cooling is
insufficient because the heat sink is dirty, the power
elements may be destroyed.
When the heat sink on the back of the amplifier is too dirty,
clean the heat sink, for example, by blowing air. Consider the
use of a structure that prevents the heat sink from being
directly exposed to coolant.
For the installation condition, refer to "FANUC SERVO
AMPLIFIER αi series Descriptions (B-65282EN)."
(b) The parameters specific to the motor are not set correctly.
Referring to "FANUC AC SPINDLE MOTOR αi series
Parameter Manual (B-65280EN)," check the parameters
specific to the motor.