Using Intelligent Input Terminals
Oper
ations
and Monitor
ing
4–14
Free-run Stop
When the terminal [FRS] is turned ON, the inverter stops the output and the motor enters
the free-run state (coasting). If terminal [FRS] is turned OFF, the output resumes sending
power to the motor if the Run command is still active. The free-run stop feature works
with other parameters to provide flexibility in stopping and starting motor rotation.
In the figure below, parameter B_88 selects whether the inverter resumes operation from
0 Hz (left graph) or the current motor rotation speed (right graph) when the [FRS]
terminal turns OFF. The application determines the best setting.
Parameter B_03 specifies a delay time before resuming operation from a free-run stop.
To disable this feature, use a zero delay time.
Motor
speed
[FW],
[RV]
Zero-frequency start
Motor
speed
Resume from motor speed
wait time
B 03
B_88 = 00
B_88 = 01
1
0
t
t
FRS
FRS
[FW],
[RV]
1
0
1
0
1
0
Option
Code
Terminal
Symbol
Function Name
Input
State
Description
11
FRS
Free-run Stop
ON
Causes output to turn OFF, allowing motor to
free run (coast) to stop
OFF
Output operates normally, so controlled deceler-
ation stops motor
Valid for inputs:
C_01, C_02, C_03, C_04,
C_05
Required settings:
B_03, B_88, C_11 to C_15
Notes:
•
When you want the [FRS] terminal to be active low
(normally closed logic), change the setting (C_11 to
C_15) that corresponds to the input (C_01 to C_05)
that is assigned the [FRS] function.
Example (requires input configuration—
see page
See I/O specs on page
1
2
3
4
5
L
P24
FRS