Mitsubishi Electric FR-A700 Series, Technical Manual

Page: 528 / 550

562
PRACTICAL CIRCUITS
4.2 Remote operation
(common)
4.2.1 Use of the FR-FK motorized speed setter
(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 Set [ Pr. 75 = 1 ] "Reset input is enabled only when the fault occurs" to disable resetting of the inverter during normal operation.
(If the inverter is reset during normal operation, the motor coasts to a stop. This setting is to prevent the inverter from resulting
in an alarm if the motor is still coasting when the inverter has returned from the reset status.)
*4 When the power supply is 400V class, install a step-down transformer.
*5 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)
common
common
IM
U
V
W
R
S
T
MCCB
T
*4
F
MC
B
MC
MC
C
CR1
FR-FK
200V
ACC
DEC
P24
ST 2
5
0V
M
C
CR1
C
R
1
CR2
C
R
2
Hz R
PB
FM
SD
RES
*3
STF(STR)
5
2
Power
supply
DC power supply
Start switch
Reset
Calibration
resistor
1/3W10k
Twisted cable or twisted
shielded cable used
Inverter
Motor
Ground
Frequency
meter
Moving-coil
type 1mA
Related parameter
Reset selection [ Pr. 75 ]
"OFF" "ON"
Ready
Acceleration
Deceleration
motorized speed
setter