! ! ! ! Data line filter
Noise entry can be prevented by providing a data line filter for the detector or other
! ! ! ! Data examples
By decreasing the carrier frequency, the
noise terminal voltage* can be reduced.
Use Pr. 72 to set the carrier frequency to
a low value (1kHz).
Though motor noise increases at a low
carrier frequency, selection of Soft-PWM
will make it unoffending.
voltages at different carrier frequencies
Average terminal voltage
Carrier frequency 10kHz
Carrier frequency 1kHz
Noise frequency (MHz)
* Noise terminal voltage:Represents the magnitude of noise propagated from the
! ! ! ! Example of counter measures against noise
to inverter input side.
Install filter FR-BIF to
inverter input side.
Separate inverter and power line
by more than 30cm and at least
10cm from sensor circuit.
Do not earth (ground) control
Do not earth (ground) control cable.
inverter to the power supply.
Control box Reduce carrier frequency.
INSTALLATION AND WIRING
By using shielded cables as signal
cables, induction noise can be reduced
greatly (1/10 to 1/100). Induction noise
can also be reduced by moving the
signal cables away from the inverter
(Separation of 30cm reduces noise to 1/
2 to 1/3.)
By fitting the FR-BSF01 or BLF on the
inverter output side, induction noise to
the signal cables can be reduced.
Noise induced to signal cables by
inverter output cables
Twisted pair cable
20 30 40 50
Line-to-line distance d (cm)
inverter output side.
Use 4-core cable for motor power
cable and use one wire as
earth (ground) cable.
Use twisted pair shielded cable.
Do not earth (ground) shield but connect it to
signal common cable.
･ Inverter: FR-E520-3.7K
･ Motor: FR-JR 4P 3.7kW
･ Output frequency: 30Hz
･ Noise form: Normal mode