WEG CFW-09 User Manual page 194

[Factory Setting]
Parameter
P296
(1) (11)
Inverter Rated
Voltage
(Rated Input Voltage)
P297 (1) (2)
Switching Frequency
Range
Unit Description / Notes
0 to 8
[ 0 for models
220-230 V
3 for models
380-480 V
6 for models
500-600 V
and 500-690 V
8 for models
600-690 V ]
-
0 to 3
[ 2 (5.0 kHz) ]
1
The rated switching frequency for each model is shown in item 9.1. When
a higher switching frequency is used, it is necessary to derate the output
current as specified in item 9.1 note 3.
Note that the switching frequency must be reduced from 5 kHz to 2.5 kHz
when the VT rated current is used in the following models: from 54 A to
130 A/220-230 V, from 30 A to 142 A/380-480 V and 63 A/500-600 V.
Note that the following models have a rated switching frequency of 2.5 kHz:
from 180 A to 600 A/380-480 V, 44 A and 79 A/500-600 V, from 107 A to
472 A/500-690 V and all 660-690 V models.
The switching frequency is a compromise between the motor acoustic
noise level and the inverter IGBTs losses. Higher switching frequencies
cause lower motor acoustic noise level, but increase the IGBTs losses,
increasing inverter components temperature, thus reducing their useful
life.
The predominant frequency on the motor is twice the switching frequency
programmed at P297.
P297 = 5.0 kHz results in an audible motor noise corresponding to
10.0 kHz. This is due to the PWM technique used.
A reduction of the switching frequency also:
- Helps reducing instability and resonance problems that may occur in
certain application conditions.
- Reduces the leakage currents to ground, which may avoid nuisance
E11 (Output Ground Fault).
CHAPTER 6 - DETAILED PARAMETER DESCRIPTION
P296
0
1
2
3
4
5
6
7
8
Table 6.46 - Inverter rated voltage selection
ATTENTION!
Set P296 according to the rated AC line voltage! Do not set
according to short term peak values.
For CFW-09 models  86 A/380-480 V,  44 A/500-600 V and
500-690 V models, also adjust the voltage selection jumper
(Refer to item 3.2.3).
P297 Switching Frequency
0
1
2
3
Table 6.47 - Switching frequency selection
Inverter Rated Voltage
220 V/230 V
380 V
400 V/415 V
440 V/460 V
480 V
500 V/525 V
550 V/575 V
600 V
660 V/690 V
1.25 kHz
2.5 kHz
5.0 kHz
10.0 kHz
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