Specifications

3
3.WIRING
3– 59
CAUTION
When an alarm has occurred, remove its cause, make sure that the opera-
tion signal is not being input, ensure safety, and reset the alarm before
restarting operation.
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.
3-6 Alarm occurrence timing chart
ON
OFF
ON
OFF
Valid
Invalid
ON
OFF
ON
OFF
ON
OFF
ON
OFF
Control
power
supply
Base circuit
Dynamic
brake
Servo on
(SON)
Ready
(RD)
Trouble
(ALM)
Reset
(RES)
Power off
Power on
Brake operation
Brake operation
1s
Remove cause
of trouble.
50ms
or more
15ms or more
Instantaneous power failure alarm
Alarm occurs.
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 regenera-
tive (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 power is restored after a 100ms or loger power failure of the
control power supply or after a drop of the bus voltage to or below 200VDC. If the power
failure persists further, the control 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) Position control mode
When an alarm occurs, the home position is lost. When resuming operation after resetting
the alarm, make a return to home position.