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13. SERVO AMPLIFIERS WITH A LARGE CAPACITY (30k TO 55kW)
(b) When controlling magnetic contactor b y external sequence
1) Converter unit
When an alarm occurs on the converter unit, the s ervo-on turns OFF; however, the main circuit p ower
supply is not shut off. Therefore, shut off the m ain circuit power supply by the external sequenc e.
After cancelling the alarm on the converter u nit (when an alarm is also occurring on the dr ive unit
after cancelling the alarm on the drive unit as well), turning ON the reset command enables to
operate again.
b)
Converter unit control
power supply
Drive unit control
power supply
Main circuit
power supply
ON
OFF
ON
OFF
ON
OFF
ON
OFF
ON
OFF
Servo-on command
(from controller)
Drive unit alarm
Reset command
(from controller)
Base circuit
OFFONOFF
1.5s
50ms or more
Converter unit alarm OFFOFF ON OFF
(3s) (3s)
a) d)
Alarm occurrence
ON
Alarm occurrence
c)
ON
OFF
e)
a) in Figure
b) c) in Figure
d) in Figure
e) in Figure
Even if an alarm occurs in the converter when the drive unit is at servo off, the
drive unit does not detect the alarm.
To deactivate the alarm of the converter unit, turn t he power of the converter unit
off, and then on (b)) or make the drive unit ser vo on (c)). (Refer to section 13.6.1.)
If an alarm occurs in the converter unit when the drive unit is at servo on, the
alarm also occurs in the drive unit and the dr ive unit becomes servo off.
Shut off the main circuit power supply by the ex ternal sequence as soon as an
alarm occurs.