6
-4
Carrier Frequency
When selecting the carrier frequency, observe the following precautions items.
•
When using a device with C6-01 set to 1 (VT), adjust the carrier frequency according to the cases shown
below.
If the wiring distance between Inverter and motor is long: Set the carrier frequency low. (Use the following
values as guidelines.
If speed and torque are inconsistent at low speeds: Set the carrier frequency low.
If Inverter noise is affecting peripheral devices: Set the carrier frequency low.
If leakage current from the Inverter is large: Set the carrier frequency low.
If metallic noise from the motor is large: Set the carrier frequency high.
Carrier frequency upper limit depends on the Inverter capacity. Refer to
Factory Settings that Change with the
Inverter Capacity (o2-04)
on page 5-83.
•
When using V/f control or V/f control with PG, you can vary the carrier frequency to match the output fre-
quency, as shown in the following diagram, by setting C6-03 (Carrier Frequency Upper Limit), C6-04
(Carrier Frequency Lower Limit), and C6-05 (Carrier Frequency Proportional Gain).
*K is the coefficient determined by the set value in C6-03.
C6-03
≥
10.0 kHz: K=3
10.0 kHz > C6-03
≥
5.0 kHz: K=2
5.0 kHz > C6-03: K=1
Fig 6.1
•
With vector control, the carrier frequency is fixed by the Carrier Frequency Upper Limit in C6-03 if user-
set, or by the carrier frequency set in C6-02.
•
To fix the carrier frequency, set C6-03 and C6-04 to the same value, or set C6-05 to 0.
•
If the settings are as shown below, OPE11 (Data setting error) will occur.
Wiring Length
50 m or less
100 m or less
Over 100 m
C6-02 (carrier frequency)
setting
0 to 6 (15 kHz)
0 to 4 (10 kHz)
0 to 2 (5 kHz)
If Carrier Frequency Proportional Gain (C6-05) > 6 and C6-03 < C6-04.
If C6-01 = 0 and Carrier Frequency Selection C6-02 is set from 2 to E.
If C6-01 = 1 and Carrier Frequency Selection C6-02 is set from 7 to E.
C6-03
C6-04
Output frequency
Output frequency
×
C6-05
×
K*
E1-04
Max. Output Frequency
Carrier Frequency
