Mitsubishi Electronics FR-F740P ユーザーズマニュアル
97
Limiting the output frequency
4
(2) Set minimum frequency
⋅ Use Pr. 2 Minimum frequency to set the lower limit of the output frequency.
⋅ The output frequency is clamped by the Pr. 2 setting even the set frequency is lower than the Pr. 2 setting (The
⋅ The output frequency is clamped by the Pr. 2 setting even the set frequency is lower than the Pr. 2 setting (The
frequency will not decrease to the Pr. 2 setting.)
4.5.2
Avoiding mechanical resonance points (Frequency jump) (Pr. 31 to Pr. 36)
The above parameters can be set when Pr. 160 User group read selection = "0". (Refer to page 201)
REMARKS
⋅ When Pr. 15 Jog frequency is equal to or less than Pr. 2, the Pr. 15 setting has precedence over the Pr. 2 setting.
⋅ When stall prevention is activated to decrease the output frequency, the output frequency may drop to Pr. 2 or below.
⋅ Under IPM motor control, the estimated output frequency (rotations per minute) is used to limit the frequency. Therefore, the
⋅ When stall prevention is activated to decrease the output frequency, the output frequency may drop to Pr. 2 or below.
⋅ Under IPM motor control, the estimated output frequency (rotations per minute) is used to limit the frequency. Therefore, the
value displayed in the monitor may reach the lower limit frequency or lower.
CAUTION
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 simply switching the start signal ON, without entry of the
command frequency.
frequency according to the acceleration time setting by simply switching the start signal ON, without entry of the
command frequency.
♦ Parameters referred to ♦
Pr. 13 Starting frequency
Refer to page 113
Pr. 15 Jog frequency
Refer to page 104
Pr. 125 Terminal 2 frequency setting gain frequency, Pr. 126 Terminal 4 frequency setting gain frequency
Refer to page 193
When it is desired to avoid resonance attributable to the natural frequency of a mechanical system, these parameters
allow resonant frequencies to be jumped.
allow resonant frequencies to be jumped.
Parameter
Number
Name
Initial Value
Setting Range
Description
31
Frequency jump 1A
9999
0 to 400Hz, 9999
1A to 1B, 2A to 2B, 3A to 3B is
frequency jumps
9999: Function invalid
frequency jumps
9999: Function invalid
32
Frequency jump 1B
9999
0 to 400Hz, 9999
33
Frequency jump 2A
9999
0 to 400Hz, 9999
34
Frequency jump 2B
9999
0 to 400Hz, 9999
35
Frequency jump 3A
9999
0 to 400Hz, 9999
36
Frequency jump 3B
9999
0 to 400Hz, 9999
⋅ Up to three areas may be set, with the jump frequencies set
to either the top or bottom point of each area.
⋅ The settings of frequency jumps 1A, 2A, 3A are jump points,
and operation is performed at these frequencies in the jump
areas.
areas.
Example 1 To fix the frequency to 30Hz in the range 30Hz to 35Hz, set 35Hz in Pr. 34
and 30Hz in Pr. 33.
Example 2 To jump the frequency to 35Hz in the range 30Hz to 35Hz, set 35Hz in Pr.
33 and 30Hz in Pr. 34.
CAUTION
⋅ During acceleration/deceleration, the running frequency within the set area is valid.
Pr.31
Frequency jump
Pr.32
Pr.33
Pr.34
Pr.35
Pr.36
Set frequency (Hz)
Pr.34:35Hz
Pr.33:30Hz
Pr.33:35Hz
Pr.34:30Hz