Mitsubishi Electric C70 Setup Manual page 585

MITSUBISHI CNC
Appendix 2 Explanation of Alarms
Alarm No.
NC-DRV communication: Protocol error 2
39
An error was detected in the axis information data received from the CNC.
Investigation details
1 Check the alarm No. "34" items.
Alarm No.
Overcurrent
3A
Excessive current was detected in the motor drive current.
Investigation details
[1] Check whether vibration is occurring at
the table or spindle.
1
[2] Check if the vibration caused by the load
fluctuation is occurring.
Check the repeatability of the alarm at the
rapid traverse feed for the servo and at
2 acceleration/deceleration for the spindle.
(Note) Check the phenomenon caused by
the load fluctuation.
For the servo, perform the rapid traverse
feed repeatedly and check if the max.
3 current value is within the tolerable value.
For the spindle, check the load meter value
at the unloaded max. rotation speed.
Disconnect the power cable (U,V,W) from
the terminal block and the cannon plug from
4
the motor. Check the insulation of the cable
and motor with a tester.
Check the insulation between the motor
5
power cable and FG.
Check if there is any abnormality in the
6 motor's ambient environment.
(Ex. Ambient temperature, cutting water)
Alarm No.
Power module overheat
3B
Thermal protection function in the power module has started its operation.
Investigation details
Check that the fan of the drive unit is rotating
1
correctly.
Check whether the heat dissipating fins are
2
dirty.
Measure the drive unit's ambient
3
temperature.
Check if there is any abnormality in the
unit's ambient environment.
4
(Ex. Ambient temperature, noise,
grounding)
568
Investigation results
Investigation results
Vibration is occurring.
There is no vibration.
The alarm occurs.
The alarm does not occur.
The displayed value is high.
The displayed value is appropriate.
The resistance value of the power cable for
each phase is not " ∞ ".
The resistance value of the motor terminal
and unit (shaft) is 1M or less.
The values below are met when measured
with a tester.
Cable: ∞
Motor terminal - unit:1M or more
There is a ground fault at the power cable.
There is no problem.
Take remedies according to the causes of the abnormality in the ambient environment.
Investigation results
Large amounts of cutting oil or cutting chips,
etc., are adhered to the fan, or the rotation
is slow.
The fan is rotating properly.
Cutting oil or cutting chips, etc., are
adhered, and the fins are clogged.
Cutting chips etc. are not adhered to the
fins.
55°C or more.
Less than 55°C.
Take remedies according to the causes of the abnormality in the ambient environment.
Remedies
Remedies
[1] Set a filter.
[2] Lower the speed loop gain (SV005/
SP005).
Check the investigation item No. 2.
Lower the speed loop gain (SV005/SP005)
to the level at which the alarm does not
occur.
Check the investigation item No. 3.
Increase the current loop gain.
Servo: SV009 to 012
Spindle: SP077 to 080 and SP081 to 084
Check the investigation item No. 4.
Replace the motor power cable.
Replace the motor.(Note) For the motors
equipped with the absolute position
detector, the zero point must be
established.
Check the investigation item No. 5.
Replace the motor power cable.
Check the investigation item No. 6.
Remedies
Clean or replace the fan.
Check the investigation item No. 2.
Clean the fins.
Check the investigation item No. 3.
Improve the efficiency cooling for the power
distribution panel.
Check the investigation item No. 4.
SV SP
SV SP
SV SP