Omron 3G3JX - V;F Curve

JX Quick Start Guide 17
PROGRAMMING JX
Be careful to avoid specifying too long braking time or too high carrier frequency that can cause motor overheating. If you use
DC injection braking is recommended to use motors with a built-in thermistor and wire it to inverter’s thermistor input.
3.7 V/F curve
The inverter generates the motor output according to the V/F algorithm selected on parameter A044. The factory default is Con-
stant torque (“00”). Review following descriptions to help you choose the best torque control algorithm for your application:
• Constant torque characteristics (VC) - Output voltage is proportional to output frequency. While proportional from 0 Hz to
base frequency, the output voltage is constant from base to maximum frequencies regardless of the frequency.
• Reduced torque characteristics (VP 1.7th power) - Suitable for a fan or pump that does not require large torque in a low
speed range. These provide high efficiency, reduced noise and vibration, owing to reduced output voltage in a low speed
range.
• Special reduced torque characteristics (Special VP) - Suitable for a fan or pump that requires torque in a low speed range
using VC characteristics at this area.
Period a: Provides constant torque characteristics (VC) within a range from 0 Hz to 10% of base frequency. (Example) If the
base frequency is 50 Hz, the inverter provides constant torque characteristics within a range from 0 to 5 Hz.
Period b: Provides reduced torque characteristics within a range from 10% to 100% of the base frequency. The inverter out-
puts voltage based on a curve of the 1.7th power of the frequency.
A053 DC injection braking delay time The delay from the end of controlled deceleration to start of DC
braking (motor free runs until DC braking begins)
0.0 to 5.0 s
A054 DC injection braking power 0. to 100.%
A055 DC injection braking time Sets the duration for DC braking
0.0 to 60.0 s
A056 DC injection braking method
selection
00: Edge operation
01: Level operation
Parameter Parameter name Description
A044 V/F characteristics selection 00: Constant torque characteristics (VC)
01: Reduced torque characteristics (VP 1.7th power)
06: Special reduced torque characteristics (Special VP)
A244 2nd V/F characteristics selection
Parameter Parameter name Description
0
Output
voltage
(100%)
Base frequency
(A003/A203)
Output
frequency (Hz)
Max. frequency
(A004/A204)
0
Output
voltage
(100%)
Base frequency
(A003/A203)
Output
frequency (Hz)
Max. frequency
(A004/A204)
VP (1.7th
power of VP)
0
Output
voltage
(100%)
Base frequency
(A003/A203)
Output
frequency (Hz)
Max. frequency
(A004/A204)
VC
VP
(1.7th power)
10% of base
frequency
ab c