Chapter 4 Parameters
4-64
EF
Frequency
Frequency
frequency output
motor
speed
EF
operation
command
stops according to
decel eration time
When Pr.02.02 is set to 2 or 3
frequency
output
free run to stop
operation
command
When Pr.02.02 is set to 0 or 1
motor
speed
02.03
PWM Carrier Frequency Selections
Unit: Hz
115V/230V/460V Series
Power
0.25 to 15hp (0.2kW to 22kW)
Setting Range
1 to 15 kHz
Factory Setting
8 kHz
This parameter determines the PWM carrier frequency of the AC motor drive.
1kHz
8kHz
15kHz
Carrier
Frequency
Acoustic
Noise
Electromagnetic
Noise or leakage
current
Heat
Dissipation
Current
Wave
Significant
Minimal
Significant
Minimal
Minimal
Significant
Minimal
Significant
From the table, we see that the PWM carrier frequency has a significant influence on the
electromagnetic noise, AC motor drive heat dissipation, and motor acoustic noise.
The PWM carrier frequency will be decreased automatically by heat sink temperature and
output current of the AC motor drive. It is used as a necessary precaution to prevent the AC
motor drive from overheating and thus extends IGBT’s life. If the user wants to fix carrier within
the rated range and won’t change by the change of the surrounding temperature and
frequently load. Please refer to Pr.02.18 for Selection of Carrier Modulation.
Related parameters: Pr.02.18(Selection of Carrier Modulation) and Pr.03.08(Fan Control).
