Alarm Occurrence Timing Chart - Mitsubishi melservo-j2 series Instruction Manual

3. SIGNALS AND WIRING

3.5 Alarm Occurrence Timing Chart

CAUTION
When an alarm occurs in the servo amplifier, the base circuit is shut off and the servo motor is coated to a
stop. Switch off the main circuit power supply in the external sequence. To reset the alarm, switch the
control circuit power supply off, then on.
However, the alarm cannot be reset unless its cause of occurrence is removed.
Power supply ON
OFF
Base circuit ON
OFF
Dynamic brake Valid
Invalid
Servo on ON
(SON) OFF
Ready ON
(RD) OFF
Trouble ON
(ALM) OFF
Reset ON
(RES) OFF
Precautions for alarm occurrence
1) Overcurrent, overload 1 or overload 2
If operation is repeated by switching control circuit power off, then on to reset the overcurrent
(A.32), overload 1 (A.50) or overload 2 (A.51) alarm after its occurrence, without removing its cause,
the servo amplifier and servo motor may become faulty due to temperature rise. Securely remove
the cause of the alarm and also allow about 30 minutes for cooling before resuming operation.
2) Regenerative alarm
If operation is repeated by switching control circuit power off, then on to reset the regenerative
(A.30) alarm after its occurrence, the external regenerative brake resistor will generate heat,
resulting in an accident.
3) Instantaneous power failure
Undervoltage (A.10) occurs if control power is restored after a 100ms or longer power failure or
power is restored after the bus voltage has dropped to 200VDC or less. If the power failure further
continues, control power is switched off. When the power failure is reset in this state, the alarm is
reset and the servo motor will start suddenly if the servo-on signal (SON) is on. To prevent hazard,
make up a sequence which will switch off the servo-on signal (SON) if an alarm occurs.
4) Incremental system
When an alarm occurs, the home position is lost. When resuming operation after deactivating the
alarm, make a return to home position.
• When an alarm has occurred, remove its cause, make sure that the operation signal
is not being input, ensure safety, and reset the alarm before restarting operation.
Brake operation
0.8s
Alarm occurs.
Remove cause of trouble.
50ms or
more
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Power off
Power on
Brake operation
Instantaneous power fallure alarm
100ms or more