Mitsubishi Electric FR-F820-00046, Instruction Manual

Page: 437 / 940

Parameters (T) Multi-Function Input Terminal Parameters
FR-F800 5 - 265
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 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 Positive side
100% > Pr. 849 Negative side
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.
Fig. 5-123:
Offset setting
I002647E
NOTE Under PID control, the analog input filter is invalid (no filter).
Parameters referred to
Pr. 73 Analog input selection => page 5-255
Pr. 125, C2 to C4 (bias and gain of the terminal 2 frequency setting) => page 5-266
0% 100%
0% 200% 100%
Slope determined
according to Pr. 125
and C2 to C4
Slope does not
change.
Speed setting
signal
Pr. 849 setting
(10 V or 5 V)
Fr
e
q
u
e
n
c
y
command