Increasing The Starting Torque (Pr. 0); Limiting The Maximum And Minimum Output Frequency (Pr. 1, Pr. 2) - Mitsubishi Electric FR-A720-0.4K Instruction Manual

3.2.4

Increasing the starting torque (Pr. 0)

Set this parameter when "the motor with a load will not rotate", "an
alarm [OL] is output, resulting in an inverter trip due to [OC1], etc.
When the motor with a load will not rotate, increase the Pr. 0 value
1% by 1% unit by looking at the motor movement. (The guideline is
for about 10% change at the greatest.)
Refer to page 53 for how to change the parameter setting.
Parameter
Name
Number
0 Torque boost
REMARKS
· A too large setting may cause the motor to overheat, resulting in an overcurrent trip (OL (overcurrent alarm) then E.OC1
(overcurrent trip during acceleration)), overload trip (E.THM (motor overload trip), and E.THT (inverter overload trip)).
(When a fault occurs, release the start command, and decrease the Pr. 0 setting 1% by 1% to reset. (Refer to page 53)
POINT
If the inverter still does not operate properly after the above measures, adjust Pr. 80, Pr. 81 (Advanced magnetic flux
vector control), Pr.800 (Real sensorless vector control). The Pr.0 setting is invalid under Advanced magnetic flux vector
control, Real sensorless vector control and vector control. (Refer to Chapter 4 of
3.2.5

Limiting the maximum and minimum output frequency (Pr. 1, Pr. 2)

Motor speed can be limited. Refer to page 53 for how to
change the parameter setting.
Parameter
Name
Number
1 Maximum frequency
2 Minimum frequency
REMARKS
· The output frequency is clamped by the Pr. 2 setting even if the set frequency is lower than the Pr. 2 setting (The frequency will
not decrease to the Pr. 2 setting.)
Note that Pr. 15 Jog frequency has higher priority than the minimum frequency.
· When the Pr. 1 setting is changed, frequency higher than the Pr. 1 setting can not be set by
· When performing a high speed operation at 120Hz or more, setting of Pr. 18 High speed maximum frequency is necessary.
(Refer to Chapter 4 of the Instruction Manual (Applied).)
If the Pr. 2 setting is higher than the Pr. 13 Starting frequency value, note that the motor will run at the set frequency
according to the acceleration time setting by merely switching the start signal on, without entry of the command
frequency.
V/F V/F V/F
Initial Value
6%
0.4K, 0.75K
4%
1.5K to 3.7K
3%
5.5K, 7.5K
2%
11K to 55K
1%
75K or higher
Output frequency
(Hz)
Pr.1
Pr.18
Clamped at the
minimum frequency
Setting
Initial Value
120Hz
55K or lower
0 to 120Hz Set the upper limit of the output frequency.
60Hz
75K or higher
0Hz 0 to 120Hz Set the lower limit of the output frequency.
CAUTION
100%
Output
voltage
Pr.0
Setting
Pr.46
range
Pr.112
0
Setting
Range
Motor torque in the low-
frequency range can be
0 to 30%
adjusted to the load to increase
the starting motor torque.
the Instruction Manual (Applied).)
Pr.2
0 5, 10V
(4mA) (20mA)
Description
Range
.
Before operation
Output Base
frequency
frequency
(Hz)
Description
Clamped at the
maximum frequency
Frequency setting
59
3