563
4
P
RACTICAL CIRC
UI
T
S
PRACTICAL CIRCUITS
4.2.2
Automatic operation using 4 to 20mADC current signal
(common)
*1
Separate the signal cable from the power cable. Not doing so can cause the signal line to act as an antenna and be affected
more easily by external noise.
*2
The frequency meter connection cable may be increased up to 200m in length. (Install the calibration resistor near the
frequency meter.)
*3
When the electric channel length between the inverter and motor is long:
1) As the output voltage of the inverter includes high frequency, continuous leakage current due to the to-ground
capacitances in the inverter-to-motor electric channel increases and the earth leakage circuit breaker or earth
leakage relay may operate unnecessarily.
Wire the cables between the inverter and motor over the shortest distance and increase the electric channel-to-
ground distance.
2) At a low frequency, the motor torque may decrease due to a voltage drop in the cables. (Refer to page 530)
*4
When an inverter with a regenerative brake resistor is used for cyclic or heavy duty operation, it is recommended to install a
magnetic contactor in the primary side to prevent discharging resistor from overheat/burnout if the regenerative brake transistor
is damaged due to the thermal capacity shortage of the discharging resistor, and excessive regenerative brake duty, etc.
*5
When running two inverters with a 4 to 20mADC current signal at the same time, connect terminals 4-5 in series. Note the
power supply capacity of the 4 to 20mADC signal.
common
IM
U
V
W
R
S
T
MCCB
Hz
R
SD
FM
CR1
CR2
10
2
5
4 to 20mADC
C
X
T
X
CX
TX
CR1
C
R
1
C
R
2
STF(STR)
AU
SD
4
4
5
*5
200VAC
㧗
㧙
MC
*4
Power
supply
Frequency
meter
Calibration
resistor
Frequency setting
potentiometer
Start switch
Stop switch
Inverter
Motor
Ground
Twisted cable or twisted
shielded cable used
Remote installation
Current signal
for automatic
operation
DC
power
supply
Manual operation
Automatic operation
Summary of Contents for FR-A700 Series
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Page 440: ...474 PARAMETER MEMO ...
Page 522: ...556 SELECTION MEMO ...