Fuji Electric FVR-C11S-7EN Series - Others; Harmonic Component; Noise; Leakage Current

2 Installation and Connection 2-21
FVR-C11S-EN
2
2-4 Others
2-4-1 Harmonic component
A harmonic component which ma
y
influence the
phase-advance capacitor and
g
enerator is in-
cluded in the inverter input current. If necessar
y
,
connect a power-factor correctin
g
DC reactor
(DCR) (option) for the inverter.
2-4-2 Noise
When noise
g
enerated from the inverter ma
y
af-
fect peripheral equipment, and noise
g
enerated
from peripheral equipment ma
y
malfunction the
inverter, the followin
g
basic countermeasures
should be taken.
1) When noise affects other devices via power
and
g
round wires
z
Separate the
g
round of the inverter and
that of the affected device.
z
Connect a noise filter to the inverter power
wire.
z
Use an isolation transformer to separate
the power suppl
y
of the inverter and that of
the affected device.
2) When another device is affected b
y
induction
or radiation
z
Separate the main circuit wirin
g
of the in-
verter from the control wirin
g
and wirin
g
of
the affected device.
z
Encase the inverter main circuit wirin
g
in a
metal tube and
g
round the metal tube near
the inverter.
z
Encase the inverter in a metal rack and
g
round the rack.
z
Connect a noise filter to the inverter power
wire.
3) When noise
g
enerated from peripheral equip-
ment affects the inverter
z
Use twisted or twisted-pair shielded wires
for the inverter control wirin
g
. Ground the
shields.
z
Connect a sur
g
e absorber in parallel to the
coil of the ma
g
netic contactor and sole-
noid.
z
If the power suppl
y
includes much distor-
tion of the waveform or sur
g
e, connect an
impedance matchin
g
AC reactor for coor-
dination of power suppl
y
.
2-4-3 Leaka
g
e current
Leaka
g
e current flows throu
g
h the inverter I-O
wirin
g
and motor stra
y
capacitance when the in-
verter transistor is turned on and off.
Table 2-3-3 lists the countermeasures for the
problems caused b
y
the leaka
g
e current.
Table 2-3-3 Countermeasures for leaka
g
e current
Problem Countermeasures
1
Trip of earth
leaka
g
e
circuit
breaker
on main
power
suppl
y
side
1. Set the carrier
frequenc
y
lower.
2. Shorten the wirin
g
between the inverter
and motor.
3. Increase the
ELCB/RCD sensitivit
y
current.
4. Replace the
ELCB/RCD with an
ELCB/RCD that is de-
si
g
ned for hi
g
h frequen-
cies.
2
Trip of exter-
nal thermal
O/L rela
y
1. Set the carrier frequen-
c
y
lower.
2. Increase the thermal
O/L rela
y
set value.
3. Use the inverter elec-
tronic thermal O/L
rela
y
.