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C6-02: Carrier Frequency Selection
Parameter C6-02 sets the switching frequency of the drive’s output transistors. It can be changed in order to reduce audible
noise and also reduce leakage current.
Note: The drive rated current is reduced when the carrier frequency is set higher than the default value. Refer to Rated Current Depending on
Carrier Frequency on page 133.
No. Parameter Name Setting Range Default
C6-02 Carrier Frequency Selection 1 to A, F
Determined by A1-02, o2-04.
Reset when C6-01 is changed.
Settings:
C6-02
Carrier Frequency C6-02 Carrier Frequency C6-02 Carrier Frequency
1 2.0 kHz 5 12.5 kHz 9 Swing PWM 3
2 5.0 kHz 6 15.0 kHz A Swing PWM 4
3 8.0 kHz 7 Swing PWM 1
F User defined (C6-03 to C6-05)
4 10.0 kHz 8 Swing PWM 2
Note: Swing PWM uses 2.0 kHz carrier frequency as a base but by applying special PWM patterns the audible noise of the motor is kept low.
Guidelines for Carrier Frequency Parameter Setup
Symptom Remedy
Speed and torque are unstable at low speeds.
Lower the carrier frequency.
Noise from the drive is affecting peripheral devices.
Excessive leakage current from the drive.
Wiring between the drive and motor is too long.
<1>
Audible motor noise is too loud.
Increase the carrier frequency or use Swing PWM.
<2>
<1> The carrier frequency may need to be lowered if the motor cable is too long. Refer to the table below.
<2> In Normal Duty default setting is 7 (Swing PWM), equivalent to setting 2 kHz. Increasing the carrier frequency is fine when using the drive
is set for Normal Duty, but remember that the drive rated current falls when the carrier frequency is increased.
Wiring Distance Up to 50 m Up to 100 m Greater than 100 m
C6-02 (Carrier Frequency Selection) 0 to 6 (15 kHz) 0 to 4 (10 kHz) 1, 7 to A (2 kHz)
Note: If the motor cable is fairly long when using PM Open Loop Vector, set the carrier frequency to 2 kHz (C6-02 = 1). Switch to V/f Control
if the cable is longer than 100 m.
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C6-03/C6-04/C6-05: Carrier Frequency Upper Limit/Lower Limit/Proportional Gain
Use these parameters to set a user defined or a variable carrier frequency. To set the upper and lower limits, first set C6-02
to “F”.
No. Parameter Name Setting Range Default
C6-03 Carrier Frequency Upper Limit 1.0 to 15.0 kHz
<1>
C6-04 Carrier Frequency Lower Limit (V/f only) 1.0 to 15.0 kHz
C6-05 Carrier Frequency Proportional Gain (V/f only) 0 to 99
<1> The default value is determined by the control method (A1-02) as well as the drive capacity (o2-04), and is reinitialized when the value set to
C6-01 is changed.
Setting a Fixed User Defined Carrier Frequency
A carrier frequency between the fixed selectable values can be entered in parameter C6-03 when C6-02 is set to “F”. In
V/f Control, parameter C6-04 must also be adjusted to the same value as C6-03.
Setting a Variable Carrier Frequency (V/f Control only)
In V/f Control, the carrier frequency can be set up to change linearly with the output frequency. In this case the upper and
lower limits for the carrier frequency and the carrier frequency proportional gain (C6-03, C6-04, C6-05) have to be set as
shown in Figure 5.29.
C6-03
C6-04
E1-04
x C6-05 x K*
Output Frequency
Output
Frequency
Max Output Frequency
Carrier Frequency
Figure 5.29
Carrier Frequency Changes Relative to Output Frequency
5.3 C: Tuning
132
SIEP C710606 20 OYMC AC Drive - V1000 User Manual
7/16/2008-13:23
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