Mitsubishi Electric FR-A700 Technical Manual page 487

(3) Specific technique examples
1) Techniques and effects
The following levels (estimated values) of effects are
expected for the technique examples (on the next page).
Use this data for reference when determining the priority of
actual techniques.
Technique
A Decrease carrier frequency [Pr. 72]
B Increase input S/W filter constant [Pr. 74]
C Install capacitor type filter FR-BIF (-H)
Install common mode filter FR-BSF01 or
D
FR-BLF
Run power supply cables in metal conduit
E or use shielded cables as power supply
cables
Install insulated transformer or noise
F
reduction transformer
G Separate power supply line
Install common mode filter FR-BSF01 or
H
FR-BLF
Run output cables in metal conduit or use
I
shielded cables
Use 4-core cable as motor power line and
J
use one wire as ground cable
Use twisted pair shielded cable as sensor
K
signal line
L Connect shield to common of sensor signal
Do not earth sensor power unit to control
M
box etc. directly
N Earth sensor power unit via capacitor
Use twisted pair shielded cables for signal
O inputs and connect shield to common (input
terminal) SD
Use twisted pair shielded cables for speed
P
inputs and connect shield to terminal 5
Insert ferrite cores available commercially
Q into speed input cables (output side of
mating equipment)
Lower impedance of output circuit of mating
R
equipment
Separate more than 30cm from inverter and
S
power line
T Do not run cables in parallel or together
U Provide masking shield
V Keep away from ground
Insert ferrite cores available commercially
W
in input side of mating equipment
Effects of EMI reduction techniques
Air propagated EMI
Radiation Radiation
Radiation
from
from
power
inverter
cables cables
—
—
—
—
— —
— —
— —
— —
— —
— —
— —
— —
521
Symbol meanings
: Large effect
: Effect produced
: Small effect
— : No effect
EMI Propagation
Electro- Electro-
magnetic static
from induction induction
motor interference interference
— — —
— — —
— — —
— — —
— — —
—
— — —
— — —
—
—
— — —
SELECTION
Electrical path
propagated EMI
Leakage
Power current of
cables ground
cable
— —
—
—
—
—
— —
—
3
— —
—
—
—
— —
— —
— —
— —
— —
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