Input Filter Time Constant (Pr.74) - Mitsubishi Electric F700 Instruction Manual

Frequency setting by analog input (terminal 1, 2, 4)
(2) Override function (Pr.252, Pr.253)
Forward
rotation
Override
setting
Main
(+)
speed
(-)
Override connection diagram
200
150
Pr.252
100
Pr.253
50
0
0V
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

3.15.3 Input filter time constant (Pr.74)

The time constant of the primary delay filter can be set for the external frequency command (analog input
Pr. 73
(terminal 1, 2, 4) signal).
page 127
Pr. 75
page 136
Parameter
Number
74 Input filter time constant
The above parameters can be set when Pr. 160 User group read selection = "0". (Refer to page 140)
⋅ 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.)
128
⋅ 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
Inverter
speed setting and the terminal 2 for the override signal. (When the main speed of
STF
the terminal 1 or terminal 4 is not input, compensation made by the terminal 2
PC
becomes invalid.)
10
⋅ Using Pr. 252 and Pr. 253, set the override range.
2
⋅ How to find the set frequency for override
5
1
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
Initial value
(50% to 150%)
2.5V 5V
(5V) (10V)
Voltage across terminals 2-5
Refer to page 71
Refer to page 125
Name
Example)When Pr. 73 = "5"
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
Terminal 1 input voltage (V)
Initial Value Setting Range
1 0 to 8
Compensation amount (%)
100(%)
Terminal 2 5VDC
input(150%)
Terminal 2 2.5VDC
input(100%)
Terminal 2 0V
input(50%)
2.5 5
Description
Set the primary delay filter time
constant for the analog input. A
larger setting results in a larger
filter.