Toshiba VF-FS1 - Manual (Page 123)

E6581381
F-27
6
6.11 PWM carrier frequency
H : PWM carrier frequency
H : Random mode
H : Carrier frequency control mode selection
• Function
1) The H parameter allows the tone of the magnetic noise from the motor to be changed by
switching the PWM carrier frequency. This parameter is also effective in preventing the motor from
resonating with its load machine or its fan cover.
2) In addition, the H parameter reduces the electromagnetic noise generated by the inverter.
Reduce the carrier frequency to reduce electromagnetic noise. Note: Although the electromagnetic
noise level is reduced, the acoustic noise of the motor is increased.
3) The random mode reduces motor electromagnetic noise by changing the pattern of the reduced carrier
frequency.
[Parameter setting]
Title Function Adjustment range Default setting
H PWM carrier frequency 6.0-16.0 (kHz) (*)
12.0 or 8.0
Depending on model
( ⇒ See page K-14)
H Random mode 0: Disabled, 1: Enabled 0
H
Carrier frequency control mode
selection
0: Carrier frequency not reduced
automatically
1: Carrier frequency reduced
automatically
2: Carrier frequency not reduced
automatically
Support for 400V models
3: Carrier frequency reduced
automatically
Support for 400V models.
1
* Reduction of rated current will be required if the PWM carrier frequency is modified for each applicable motor
model. Refer to the following figure.
* When the PWM carrier frequency is set high, selecting “Carrier frequency not reduced automatically” causes
the inverter to be tripped more easily than selecting “Carrier frequency reduced automatically.”