Response Level Of Analog Input And Noise Elimination (Pr. 74) - Mitsubishi Electric FR-D720-008 Instruction Manual

Frequency setting by analog input (terminal 2, 4)
Forward rotation
4 to 20mADC
Current input
Frequency setting
equipment
Connection diagram using terminal 4 (4 to 20mADC)
Reverse Forward
rotation
Pr. 125
Reversible
Not
reversible
C2(Pr. 902)
0 2.5V
C3(Pr.902)
Frequency setting signal
Reversible operation example
NOTE
When reversible operation is set, be aware of reverse rotation operation when analog input stops (only the start
signal is input).
When reversible operation is valid, reversible operation (0 to 4mA: reverse operation, 4mA to 20mA: forward
operation) is performed by terminal 4 in the initial setting.
Parameters referred to
Pr. 125 Terminal 2 frequency setting gain frequency, Pr. 126 Terminal 4 frequency setting gain frequency
Pr. 561 PTC thermistor protection level
C2 (Pr. 902) Terminal 2 frequency setting bias frequency to C7 (Pr. 905) Terminal 4 frequency setting gain

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

The time constant of the primary delay filter can be set for the external frequency command (analog input (terminal 2, 4)
signal).
Parameter
Number
74 Input filter time constant
The above parameter can be set when Pr. 160 Extended function display selection = "0". (Refer to page 160)
Valid for eliminating noise of 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 1ms to 1s with the setting
of 0 to 8.)
150
Inverter
STF
AU
SD
4
5
rotation
Terminal 2
input (V)
5V
C4(Pr.903)
Refer to page 98
Name Initial Value
(3) Perform operation by analog input selection
When the pressure or temperature is controlled constantly by a fan,
pump, etc., automatic operation can be performed by inputting the
output signal 4 to 20mADC of the adjuster across the terminals 4-5.
The AU signal must be turned ON to use the terminal 4.
(4) Perform forward/reverse rotation by analog input
(polarity reversible operation)
Setting "10" or "11" in Pr. 73 and adjusting Pr. 125 (Pr. 126) Terminal 2
frequency setting gain frequency (Terminal 4 frequency setting gain
frequency) and C2 (Pr. 902) Terminal 2 frequency setting bias frequency to
C7 (Pr.905) Terminal 4 frequency setting gain makes reverse operation
by terminal 2 (terminal 4) valid.
Example)When performing reversible operation by terminal 2 (0 to 5V)
input
1) Set "11" in Pr. 73 to make reversible operation valid.
Set frequency at maximum analog input in Pr. 125 (Pr. 903)
2) Set 1/2 of the value set in C4 (Pr. 903) in C3 (Pr. 902).
3) Reversible operation is performed when 0 to 2.5VDC is input and
forward rotation when 2.5 to 5VDC.
Setting Range
1 0 to 8
Refer to page 151
Refer to page 151
Description
Primary delay filter time constant for the
analog input.
A larger setting results in a larger filter.