Mitsubishi Electric FR-A820-00046 Instruction Manual page 619

Parameters
Analog input time constant (Pr. 74)
● It is effective to eliminate noise on the frequency setting circuit.
● Increase the filter time constant if steady operation cannot be performed due to noise, etc.
A larger setting results in slower response. (The time constant can be between 0 and 8, which are
about 5 ms to 1 s.)
Analog speed command input time constant (Pr. 822, Pr. 832)
● Set the primary delay filter time constant to the external speed command (analog input com-
mand) by using Pr. 822 "Speed setting filter 1".
● To change the time constant, for example, in a case where only one inverter is used to switch
between more than one motor, use Pr. 832 "Speed setting filter 2".
● Pr. 832 "Speed setting filter 2" is enabled when the RT signal is ON.
Analog torque command input time constant (Pr. 826, Pr. 836)
● Set the primary delay filter time constant to the external torque command (analog input com-
mand) by using Pr. 826 "Torque setting filter 1".
● To change the time constant, for example, in a case where only one inverter is used to switch
between two motors, use Pr. 836 "Torque setting filter 2".
● Pr. 836 "Torque setting filter 2" is enabled when the RT signal is ON.
Analog speed command input offset adjustment (Pr. 849)
● This is used to set a range in which the motor is stopped for prevention of incorrect motor
operation in a very low speed rotation by the analog input speed command.
● Regarding the Pr. 849 "Analog input offset adjustment" value 100% is 0, the offset voltage is set
as described below:
100% < Pr. 849
100% > Pr. 849
The detailed calculation of the offset voltage is as described below:
Offset voltage [V] = Voltage at the time of 100% (5 V or 10 V ) × (Pr. 849 – 100)/100
It depends on the Pr. 73 setting.
0%
NOTE Under PID control, the analog input filter is invalid (no filter).
Parameters referred to
Pr. 73
Pr. 125, C2 to C4
FR-A800
Positive side
Negative side
Slope determined
according to Pr. 125
and C2 to C4
Slope does not
change.
Speed setting
0% 100%
signal
(10 V or 5 V)
Pr. 849 setting
100% 200%
Analog input selection
(bias and gain of the terminal 2 frequency setting)
(T) Multi-Function Input Terminal Parameters
Fig. 5-202:
Offset setting
=>
=>
I002647E
page 5-406
page 5-418
5 - 417