4-3
Chap. 4 RUNNING THE MOTOR
The MD-/LD-mode inverter is subject to restrictions on the function code data setting range and internal processing as listed
below.
Function
codes
Name
HD mode MD mode LD mode Remarks
F21*
DC braking
(Braking level)
Setting range:
0 to 100%
Setting range: 0 to 80%
F26
Motor sound
(Carrier
frequency)
Setting range:
0.75 to 16 kHz
(0.4 to 55 kW)
0.75 to 10 kHz
(75 to 400 kW)
0.75 to 6 kHz
(500 and 630 kW)
Setting range:
0.75 to 2 kHz
(90 to 400 kW)
Setting range:
0.75 to 16 kHz
(5.5 to 18.5 kW)
0.75 to 10 kHz
(22 to 55 kW)
0.75 to 6 kHz
(75 to 500 kW)
0.75 to 4 kHz
(630 kW)
In the MD/LD mode, a value out
of the range, if specified,
automatically changes to the
maximum value allowable in the
LD mode.
F44
Current limiter
(Level)
Initial value: 160% Initial value: 145% Initial value: 130%
Switching the drive mode
between HD, MD and LD with
function code F80 automatically
initializes the F44 data to the
value specified at left.
F03*
Maximum
frequency
Setting range:
25 to 500 Hz
Upper limit:
500 Hz
Setting range: 25 to 500 Hz
Upper limit: 120 Hz
In the MD/LD mode, if the
maximum frequency exceeds
120 Hz, the actual output
frequency is internally limited to
120 Hz.
―
Current
indication and
output
Based on the rated
current level for
HD mode
Based on the rated
current level for
MD mode
Based on the rated
current level for
LD mode
―
Switching to the MD/LD mode does not automatically change the motor rated capacity (P02*) to the one for the motor with one
rank higher capacity, so configure the P02* data to match the applied motor rating as required.
4.1.5 Selecting a desired motor drive control
The FRENIC-MEGA supports the following motor drive control.
F42*
data
Drive control
Basic
control
Speed
feedback
Drive control
class
Speed control
Other
restrictions
0
V/f control
with slip compensation inactive
Frequency control ―
1
Dynamic torque vector control
―
2
V/f control
with slip compensation active
Disable V/f
Frequency control
with slip compensation
―
3
V/f control
with speed sensor
4
Dynamic torque vector control
with speed sensor
V/f
control
Enable PG V/f
Frequency control
with automatic speed
regulator (ASR)
Maximum
frequency:
200 Hz
5
Vector control
without speed sensor
Estimated
speed
w/o PG
Maximum
frequency:
120 Hz
Not available
for MD-mode
inverters.
6
Vector control
with speed sensor
Vector
control
Enable w/ PG
Speed control
with automatic speed
regulator (ASR)
Maximum
frequency:
200 Hz
V/f control with slip compensation inactive
Under this control, the inverter controls a motor with the voltage and frequency according to the V/f pattern specified by
function codes. This control disables all automatically controlled features such as the slip compensation, so no unpredictable
output fluctuation results, enabling stable operation with constant output frequency.
V/f control with slip compensation active
Applying any load to an induction motor causes a rotational slip due to the motor characteristics, decreasing the motor rotation.
The inverter’s slip compensation function first presumes the slip value of the motor based on the motor torque generated and
raises the output frequency to compensate for the decrease in motor rotation. This prevents the motor from decreasing the
rotation due to the slip.
That is, this function is effective for improving the motor speed control accuracy.
The compensation value is specified by combination of function codes P12
*
(Rated slip frequency), P09
*
(Slip compensation
gain for driving) and P11
*
(Slip compensation gain for braking).
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