Instruction manual

105

PARAMETERS

4.2.27 PWM carrier frequency (Pr. 72, Pr. 240)

Pr. 72 "PWM frequency selection"

Pr. 240 "Soft-PWM setting"

You can change the motor tone.

• By parameter setting, you can select Soft-PWM control which changes the motor

tone.

• Soft-PWM control changes motor noise from a metallic tone into an unoffending

complex tone.

• Refer to the following list and set the parameters:

Parameter

Number

Factory Setting Setting Range Remarks

72 1 0 to 15

0: 0.7kHz,

15: 14.5kHz

240 1 0, 1 1: Soft-PWM valid

Parameter

Number

Setting Description

72 0 to 15

PWM carrier frequency can be changed.

The setting displayed is in [kHz].

Note that 0 indicates 0.7kHz and 15 indicates 14.5kHz.

240

0 Soft-PWM invalid

1 When any of "0 to 5" is set in Pr. 72, Soft-PWM is made valid.

Note:1. Note that when the inverter is run at the ambient temperature above 40°C

(104°F) with a 2kHz or higher value set in Pr. 72, the rated output current of

the inverter must be reduced. (Refer to page 190 (depending upon the

inverter).)

2. An increased PWM frequency will decrease the motor sound but increase

noise and leakage currents. Therefore, perform the reduction techniques

(Refer to pages 35 to 39).

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