Response Level Of Analog Input And Noise Elimination (Pr. 74) - Mitsubishi Electric FR-F740-00023 Instruction Manual

(2) Override function (Pr. 252, Pr. 253)
Forward
Inverter
rotation
STF
PC
10
Override
2
setting
5
Main
(+) 1
speed
(-)
Override connection diagram
200
150
Pr.252
100
Pr.253
50
0
0V
Voltage across terminals 2-5
CAUTION
When the Pr. 73 setting was changed, check the voltage/current input switch setting. Different setting may cause a fault, failure
or malfunction. (Refer to page 155 for setting.)
REMARKS
The AU signal must be turned on to use the terminal 4.
When inputting compensation to multi-speed operation or remote setting, set "1" (compensation made) to Pr. 28 Multi-speed
input compensation selection. (Initial value is "0")
Parameters referred to
Pr. 28 Multi-speed input compensation selection
Pr. 73 Analog input selection

4.16.3 Response level of analog input and noise elimination (Pr. 74)

The time constant of the primary delay filter relative to external frequency command (analog input (terminal 1,
2, 4) signal) can be set.
Parameter
Name
Number
74 Input filter time constant
The above parameters can be set when Pr. 160 User group read selection = "0". (Refer to page 173)
Effective for eliminating noise in the frequency setting circuit.
Increase the filter time constant if steady operation cannot be performed due to noise. A larger setting results in
slower response. (The time constant can be set between approximately 10ms to 1s with the setting of 0 to 8.)
Use the override function to change the main speed at a fixed ratio.
Set any of "4, 5, 14, 15" in Pr. 73 to select an override.
When an override is selected, the terminal 1 or terminal 4 is used for the main
speed setting and the terminal 2 for the override signal. (When the main speed of
the terminal 1 or terminal 4 is not input, compensation made by the terminal 2
becomes invalid.)
Using Pr. 252 and Pr. 253, set the override range.
How to find the set frequency for override
Set frequency (Hz) = Main speed set frequency (Hz)
Main speed set frequency (Hz): Terminal 1, 4 input, multi-speed setting
Compensation amount (%): Terminal 2 input
Example)When Pr. 73 = "5"
Initial value
(50% to 150%)
2.5V 5V
(5V) (10V)
Refer to page 86
Refer to page 155
Initial Value
1
Frequency setting by analog input (terminal 1, 2, 4)
The set frequency changes as shown below according to the
terminal 1 (main speed) and terminal 2 (auxiliary) inputs.
75
50
37.5
25
12.5
0
0 2.5
Terminal 1 input voltage (V)
Setting Range
Set the primary delay filter time
constant for the analog input. A
0 to 8
larger setting results in slower
response.
Compensation amount (%)
100(%)
Terminal 2 5VDC
input(150%)
Terminal 2 2.5VDC
input(100%)
Terminal 2 0V
input(50%)
5
Description
161
4