Alarm Occurrence Timing Chart - Mitsubishi Electric GENERAL PURPOSE AC SERVO MR-E- A/AG 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 power supply in the external sequence. To reset the alarm, switch the power supply
from off to on, press the "SET" button on the current alarm screen, or turn the reset signal (RES) from off
to on. However, the alarm cannot be reset unless its cause is removed.
(Note)
ON
Power supply
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
Note: Shut off the power as soon as an alarm occurs.
(1) Overcurrent, overload 1 or overload 2
If operation is repeated by switching power off, then on to reset the overcurrent (AL.32),
overload 1 (AL.50) or overload 2 (AL.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 power off, then on to reset the regenerative (AL.30) alarm
after its occurrence, the external regenerative brake resistor will generate heat, resulting in an
accident.
(3) Instantaneous power failure
Undervoltage (AL.10) occurs if power is restored after a 60ms or longer power failure of the
power supply or after a drop of the bus voltage to or below 200VDC. If the power failure persists
further, the power switches 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) In position control mode (incremental)
When an alarm occurs, the home position is lost. When resuming operation after deactivating
the alarm, make a home position return.
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
1s
Alarm occurs.
Remove cause of trouble.
50ms or more
3 - 28
Power off
Power on
Brake operation
60ms or more