Changing Carrier Frequency To Reduce Noise And Magnetic Noise - Toshiba TOSVERT VF-AS3 Instruction Manual

6. 14 Changing carrier frequency to
<F300: Carrier frequency>
<F312: Random switching>
<F316: Carrier frequency control>
4
■ Function
4
The inverter noise can be reduced by decreasing the carrier frequency.
You can respond to unpleasant motor acoustic noise by increasing the carrier frequency or changing
the tone with the random switching.
6
Adjustment of carrier frequency is effective when a resonance with a load machine or motor fan
cover occurs.
However, note that a low carrier frequency causes the motor acoustic noise to increase, and a high
carrier frequency causes the inverter electro-magnetic noise to increase.
■ Parameter setting
9
■ <F300: Carrier frequency> setting
Some models require current reduction depending on the <F300: Carrier frequency> setting and
ambient temperature.
■ <F312: Random switching> setting
When you want to reduce the motor acoustic noise with a low carrier frequency, set <F312: Random
switching>. The tone can be changed.
This function works in the low output frequency range producing unpleasant acoustic noise from the
motor.
<F312: Random switching> has three different tones: "1", "2" and "3". Select the appropriate setting
for the load.
With <F300: Carrier frequency> set to 8.0 kHz or more, the motor acoustic noise decreases, and
thus the random switching does not function.
■ <F316: Carrier frequency control> setting as a measure to protect motors
against surge voltages
When a 480 V class inverter is used to operate a motor, very high surge voltages may be produced
depending on the wire length, wire routing and types of wires used.
Here are some examples of measures against surge voltages.
• Decrease <F300: Carrier frequency>.
6. [Advanced] How to use parameters
reduce noise and magnetic noise
F300 : Carrier frequency
Min: 1.0
X1000
6-52
E6582062
STOP 0.0Hz
13:14
4.0
kHz
Max: 16.0
X100 X10 X1