6
-2
Application and Overload Selections
Select the Overload to Suit the Application
Set C6-01 (CT: Low carrier constant torque, VT: High carrier variable torque) depending on the application for which the Inverter is used. The setting ranges for the Inverter carrier frequency, overload tolerance, and maximum output frequency depend on the setting in C6-01.
Related Constants
Constant
Number
Name
C6-01
CT/VT selection
C6-02
Carrier frequency selection
C6-03
*4
Carrier frequency upper limit
C6-04
*4
Carrier frequency lower limit
Description
Setting
Range
Factory
Setting
Change during
Operation
Control Methods
V/f
V/f with
PG
Open
Loop
Vector
Flux
Vector
MEMO
BUS
Register
0: CT (low carrier, constant torque,
150% per minute)
1: VT (high carrier, variable torque,
120% per minute)
Select carrier wave fixed pattern.
0: Low-noise PWM
1: 2.0 kHz
2: 5.0 kHz
3: 8.0 kHz
4: 10.0 kHz
5: 12.5 kHz
6: 15.0 kHz
F: Enables detailed settings using constants C6-03 to C6-05
Set the carrier frequency upper limit and lower limit in kHz units.
The carrier frequency gain is set as follows:
With the vector control method, the upper limit of the carrier frequency is fixed in C6-03.
Carrier frequency
0 or 1
0, 1
(C6-
01=0)
0 to F
(C6-
01=1)
1
*1
0 *1
1
(C6-
01=0)
6*2
(C6-
01=1)
2.0 to
15.0
*3
15.0 kHz
*2
2.0 to
2.5
2.0 kHz
0.4 to
15.0
*3
15.0 kHz
*2
2.0 to
2.5
2.0 kHz
No
No
No
No
Q
Q
A
A
Q
Q
A
Q
Q
A
Q 223H
Q 224H
A 225H
A No A 226H
C6-05
*4
Carrier frequency proportional gain
Output frequency x (C6-05) x K
Output frequency
(Max. output frequency)
K is a coefficient that depends on the setting of 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
00 to
99
00 No A A
* 1. Only 1(VT) can be set for 200 V Class 110 kW as well as 400 V Class 220 kW and 300 kW Inverters.
* 2. The factory settings depend on the capacity of the Inverter. The values for a 200 V Class Inverter of 0.4 kW are given.
* 3. The setting ranges depend on the capacity of the Inverter. The values for a 200 V Class Inverter of 0.4 kW are given.
* 4. This constant can be monitored or set only when F is set for C6-02.
No A 227H
Application and Overload Selections
Difference Between CT and VT
The characteristics of CT (low carrier, constant torque) and VT (high carrier, variable torque) are shown below.
CT: Low Carrier, Constant Torque
Constant Torque
VT: High Carrier, Variable Torque
Variable Torque
Torque Torque
0 Motor speed
Motor speed
Constant torque means a constant load torque for all motor speed, and it requires overload resistance capability. Applications include pushers, conveyors, cranes, and other friction or heavy loads.
Variable torque means that the load torque will decrease as the speed decreases. Normally, overload resistance capability is not required. Applications include fans and pumps.
Low carrier: Electromagnetic noise is present.
High carrier: Electromagnetic noise is not present.
Setting Precautions
C6-01 (CT/VT Selection)
When setting C6-01, observe the following precautions.
• Depending on the set value in C6-01, the setting range of the related constants is limited as follows:
C6-01 Set Value
Inverter Overload Protection Level
C6-02 (Carrier Frequency Selection)
0 (Low Carrier, Constant
Torque)
150% Inverter rated current/1 min.
0: Low carrier, low noise
1: Carrier 2.0 kHz
1 (High Carrier, Variable
Torque)
120% Inverter rated current/1 min.
0: Low carrier low noise
1: Carrier 2.0 kHz
2: Carrier 5.0 kHz
3: Carrier 8.0 kHz
4: Carrier 10.0 kHz
5: Carrier 12.5 kHz
6: Carrier 15.0 kHz
F: User-set*
E1-04 and E3-02 (Max. Output Frequency)
L3-02 (Stall Prevention Level During
Acceleration)
L3-06 (Stall Prevention Level During
Operation)
150Hz, 300 Hz
150%
150%
400 Hz
120%
120%
* Factory settings depend on Inverter capacity.
200 V and 400 V Class Inverters for 0.4 to 22 kW: 6 (15 kHz)
200 V Class Inverters for 30 kW, or 400 V Class Inverters for 30 to 55 kW: 4 (10 kHz)
200 V Class Inverters for 37 to 55 kW, or 400 V Class Inverters for 75 to 110 kW: 3 (8 kHz)
200 V Class Inverters for 75 to 90 kW, or 400 V Class Inverters for 132 to 185 kW: 2 (5 kHz)
200 V Class Inverter for 110 kW, or 400 V Class Inverters for 220 to 300 kW: 1 (2 kHz)
• When the setting in E1-04 or E3-02 is greater than 150 Hz (SPEC: C or earlier), 300 Hz (SPEC: E or later) , if C6-01 is set to 0, an OPE02 (Invalid constant setting range) error will occur.
6-
3
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.
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 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 frequency, 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).
Carrier Frequency
C6-03
C6-04
Output frequency
×
C6-05
×
K*
Output frequency
E1-04
Max. Output Frequency
*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 userset, 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.
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.
Application and Overload Selections
Carrier Frequency and Inverter Overload Current Level
When C6-01 is set to 1, the Inverter overload level will be reduced. Even when the overload current falls to below 120% constant 1 min, OL2 (Inverter overload) will be detected. The Inverter overload current reduction level is shown below.
Overload current reduction level
100%
200 V Class 37 to 90 kW
400 V Class 75 to 110 kW
200 V Class 22 kW or less
400 V Class 22 kW or less
80%
75%
50%
400 V Class 132 kW
400 V Class 160 kW
200 V Class 30 kW
400 V Class 30 to 55 kW
0 5 kHz 8 kHz 10 kHz 15 kHz
Carrier frequency
Fig 6.2 Overload Current Reduction Level
6-
5
