Mitsubishi Electric FR-D720-0.2K-G, Инструкция по эксплуатации

Страница: 58 / 302

47
Failsafe of the system which uses the drive unit
3
P
R
ECAUT
IONS FOR U
SE OF THE DRIVE UNIT
3.5 Failsafe of the system which uses the drive unit
When a fault occurs, the drive unit trips to output a fault signal. However, a fault output signal may not be output at a drive unit
fault occurrence when the detection circuit or output circuit fails, etc. Although Mitsubishi Electric assures best quality
products, provide an interlock which uses drive unit status output signals to prevent accidents such as damage to machine
when the drive unit fails for some reason and at the same time consider the system configuration where failsafe from outside
the drive unit, without using the drive unit, is enabled even if the drive unit fails.
(1) Interlock method which uses the drive unit status output signals
By combining the drive unit status output signals to provide an interlock as shown below, a drive unit failure can be
detected.
No. Interlock Method Check Method Used Signals Refer to Page
1)
Drive unit protective
function operation Operation check of an alarm contact
Circuit error detection by negative logic
Fault (ALM) signal
126
2) Drive unit operating status Operation ready signal check Operation ready (RY) signal
125
3) Drive unit running status
Logic check of the start signal and
running signal
Start signal
(STF signal, STR signal)
Drive unit running (RUN) signal
121, 125
4) Drive unit running status
Logic check of the start signal and output
current
Start signal
(STF signal, STR signal)
Output current detection (Y12)
signal
121, 128
1) Check by the drive unit fault output signal
When the drive unit's protective function activates and the
drive unit trips, the Fault (ALM) signal is output. (The ALM
signal is assigned to terminal ABC in the initial setting).
With this signal, you can check if the drive unit is
operating properly.
In addition, negative logic can be set (ON when the drive
unit is normal, OFF when the fault occurs).
2) Checking the drive unit operating status by the drive unit
operation ready completion signal
The Operation ready (RY) signal is output when the drive
unit power is ON and the drive unit becomes operative.
Check if the RY signal is output after powering ON the
drive unit.
3) Checking the drive unit operating status by the start signal
input to the drive unit and drive unit running signal.
The drive unit running (RUN) signal is output when the
drive unit is running (The RUN signal is assigned to
terminal RUN in the initial setting).
Check if the RUN signal is output when inputting the start
signal to the drive unit (forward signal is STF signal and
reverse signal is STR signal). For logic check, note that
RUN signal is output for the period from the drive unit
decelerates until output to the motor is stopped, configure
a sequence considering the drive unit deceleration time.
ON
Reset processing
(about 1s)
OFF
Reset ON
Rotation speed
ALM
(when output
at NC contact)
RES
Drive unit fault occurrence
(trip)
Time
OFF
ON
Time
Power
supply
Rotation speed
STF
RH
RY
Reset
processing
ON OFF
ON OFF
ON OFF
ON
DC injection brake
operation point
DC injection
brake operation
RUN
ON OFF