Toshiba Q9 Plus ASD, Installation & Operation Manual

Page: 234 / 434

E6581611
F-54
6
6.17 Low voltage operation
f297 : Low voltage operation upper limit frequency
f298 : Low voltage operation DC voltage
⇒ Refer to “Low voltage operation instruction manual: E6581918” for details.
6.18 PWM carrier frequency
aul
: Overload characteristic selection
f300
: PWM carrier frequency
f312 : Random mode
f316
: PWM carrier frequency control mode selection
•
Function
1) With the

parameter, the tone of the magnetic noise from the motor can 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  parameter reduces the electromagnetic noise generated by the inverter.
Reduce the carrier frequency to reduce electromagnetic noise. Note: The electromagnetic noise level is
reduced, but the acoustic noise of the motor is increased.
3) The random mode improves hearing impression by changing the pattern of the low carrier frequency.
[Parameter setting]
Title Function Adjustment range Default setting
aul
Overload characteristic
selection
0: -
1: Constant torque characteristic
（
150%-60s
）
2: Variable torque characteristic （ 120%-60s ）
0
f300
PWM carrier frequency 2.0-16.0 (kHz) 12.0
f312
Random mode
0: Disabled
1: Random mode 1
2: Random mode 2
3: Random mode 3
0
0: Carrier frequency without reduction
1: Carrier frequency with automatic reduction
2: Carrier frequency without reduction
(Support for 500V models)
f316
PWM carrier frequency
control mode selection
3: Carrier frequency with automatic reduction
(Support for 500V models)
1
Note 1: Some models need reduced current ratings, depending on f300 settings and ambient temperature.
Refer to the table on the following pages.
Note 2: Random mode is exercised when the motor is operated in a low-frequency range where it produces
annoying acoustic noise.