Mitsubishi Electric FATEC FR-A800 Manual page 115

7
REVIEW OF INSTALLATION ENVIRONMENT
(2) Specific examples of countermeasures
The following figure shows promising countermeasures against the inverter noise.
Commercial power
supply line
Input power
supply transformer
Power
supply
3300/200 V
400/200 V
F. Install an isolation
transformer or
noise suppression
transformer.
G. Separate the
A programmable controller
power supply system.
or microcomputer board
Control power
supply
400/200 V
W. Insert a commercially
available ferrite core.
R. Lower the impedance
of the output circuit.
T. Run the cables as far away
as possible. Do not run
them in parallel with each
other or bundle them.
Cross the cables in
unavoidable circumstances.
Control power supply
7.2 Noise
110
V. Separate the device
as far as possible from earth.
Radiated noise
AM radio
E. Earth one metal conduit
(conduit pipe) or shield cable
to the machine.
D. Install a filter (FR-BLF or FR-BSF01)
on the inverter input side.
C. Install an FR-BIF filter
on the inverter input
side. (For A800 series,
turn ON the built-in
EMC filter.)
O. Use a shield cable and
connect the shield to SD.
Q. Insert a commercially
available ferrite core.
P. Use a shielded
twisted pair cable and
connect the shield to
the terminal 5.
N. Ground to the enclosure
via a capacitor of
0.1 to 0.01 μF.
Wiring method inside the enclosure
Inverter
Noise filter
Terminal block
Power supply
Motor
Fig. 7.25 Example of countermeasures against noise
Note: For the radio noise, counter measures may not be effective in the
mountain area or inside a building where the airwaves are weak.
A. Lower the carrier frequency.
(Set E600 (Pr.72) to 0 (0.7 kHz).)
FR-
R,S,T
U,V,W
BLF
FR-
Inverter
BIF
STF
STR 24 VDC
SD
2
0 to 5 VDC
5
DC power supply
for the sensor
M. Do not connect earthing (grounding)
cables directly to the enclosure.
U. Shielding plate
S.30 cm or more away
from the inverter (at least 10 cm)
Terminal block
Connection
Limit switch sensor
H. Install a filter (FR-BLF or FR-BSF01)
on inverter output side.
FR-
BLF
I. Earth one metal conduit
(conduit pipe) or shield
cable to the enclosure.
J. Use 4-core cable for motor
power cable and use one
cable as earthing (grounding) cable.
B. Increase the setting value of T002 (Pr.74)
(Input filter time constant) of the inverter.
(Note that the response becomes slow.)
Chassis of the enclosure
or the machine
S. It is preferred that the inverter
and power cables are separated
from sensor circuit by 30 cm or more
(at least 10 cm).
K. Use a twisted pair shielded cable.
＋
−
L. Do not earth (ground) the
shield but connect it to
the signal common cable.
Adopt a sensor that
has high resistance
against the noise.
Motor
Sensor