Mitsubishi Electric C70 Setup Manual page 590

Alarm No.
Overload 1
50
Overload detection level became over 100%. The motor or the drive unit is overloaded.
Investigation details
Check the overload parameters.
1 Servo:SV021, SV022
Spindle:SP021,SP022
Check the items below displayed on the
drive monitor screen during operation.
<Servo>
2 Max.current 3 (%)
Overload(%)
<Spindle>
Load meter(%)
Check whether machine resonance is
occurring.
3
Check for vibration and abnormal noise at
the spindle and table.
Check whether the shaft sways when the
motor is stopped.
4
"Hunting" of the spindle
"Vibration" of the table
Check the brake operation.
5 [1] Check the brake relay.
[2] Check the connector (CN20) connection.
Check the load current with the NC Servo
6
Monitor, and investigate the machine load.
Check the PLG output waveform.
7
TS5690 cannot be checked.
8 Confirm the motor capacity selection again.
9 Try replacing the drive unit.
(Note) NR and PR resetting are not possible when the overload level is 50% or more. Do not forcibly reset (AR) by turning
the unit power OFF. If AR resetting is used at 50% or higher, the level is set to 80% when the power is turned ON
next. (Servo)
Investigation results
The standard values (below) are not set.
Servo:SV021 = 60, SV022 = 150
Spindle:SP021=60,SP022=120
IPM:SP021=300,SP022=100
The standard values are set.
Perform the machining such as rapid
traverse, where an alarm occurs. The
examples are below.
<Servo>
[1] Max.current 3 constantly displays the
maximum value.
[2] Overload increases at a rapid speed.
<Spindle>
[1] The time to display 120% lasts long.
[2] The value is higher than normal.
The value is within the supposed level and
there is no problem.
Resonance is occurring when a tool or
workpiece is mounted or during machining.
(The load inertia changes)
Resonance is not occurring.
The motor is hunting.
The motor is not hunting.
The motor brakes are not released.
The motor brake operation is normal.
The cutting load is large.
There is interference with the positioning
pin.
An excessive force is applied from the
machine.
The machine load is not large.
There is a problem.
Normal
The motor performance is insufficient.
The motor performance is sufficient.
Improved.
Not improved.
Appendix 2.16 Troubleshooting
Remedies
Set the standard values.
Investigate item 2.
Servo
[1] Mount a smaller workpiece.
[2] Increase the time constant.
[3] Check the investigation item No.6.
Spindle
[1] Lower the cutting amount.
[2] Extend the cycle time.
Investigate item 3.
Adjust the parameters.
[1] Set the optimal notch filter.
[2] Lower VGN1 (SV005,SP005).
Investigate item 4.
Adjust the parameters.
[1] Increase VGN1 (SV005, SP005).
[2] Lower VIA (SV008, SP008).
Servo: Investigate item 5
Spindle: Investigate item 7
Correct the faulty section.
Investigate item 6.
Lower the cutting load.
When using the positioning pin, turn the
servo OFF when stopped.
Check whether the ball screw is bent, or
whether there is a fault in the guide.
Investigate item 8.
Adjust the PLG output waveform.
For TS5690, reinstall.
Investigate item 8.
Lower the acceleration/deceleration rate or
cutting load.
Check the tool mounted on the spindle.
- The service life is reached.
Increase the number of teeth (chips) of the
milling cutter, etc.
Investigate item 9.
Use as it is.
Replace the motor.
C70 Setup Manual
SV SP
573