4-46
Free-run stop (FRS)
By operating the free-run stop (FRS) function, the inverter output is
cut off.
The motors will free wheel under its own momentum.
This function is used when the motor is to be stopped by the use of a
brake, like an electromagnetic brake.
If you stop the motor with a machine brake while the inverter is still
Outputting to the motor an over-current trip may occur.
Assign 11(FRS) to an intelligent input terminal.
This free-run stop function will operate when the FRS terminal is ON.
If you turn FRS terminal OFF the inverter will restart after the retry wait time b003 passes.
However when the operation command selection A002 is set to control terminal (01), the inverter restarts
during free-running.
This function will only operate when the FW terminal is ON.
On restart it is possible to select 0Hz start or matching frequency start as output methods with the free-run stop
selection b088. (Example 1, 2)
When you set the frequency setting b007 to match and the frequency detected is under this setting when the
free-run stop is released, the inverter is restarted from 0Hz.
The setting of this function is valid for selection b091 on stopping.
Set item
Function
code
Data
Description
00
0Hz start (Example 1)
Free-run stop Selection
b088
01
Equaling frequency start (Example 2)
Retry wait time
b003
0.3-100.
Units : second
Time until restart after FRS terminal is OFF.
(This is also used for Instantaneous restart.)
Frequency setting to match
b007
0.00-400.0
Units : Hz (instantaneous stop, reference to item
of insufficiency)
This sets the level to match frequency.
(Refer to item of instantaneous stop and restart.)
Chapter 4 Explanation of function
b088
: Free-run stop selection
b003
: Retry wait time
b007
: frequency setting to match
b091
: Stop mode selection
C001-C005 : intelligent input terminal
Relation code
FW
FRS
The number of
motor revolution time
0
Free-run
0Hz start
(Example 1) 0Hz start
FW
FRS
The number of
motor revolution time
0
Free-run
Start equaling
frequency
(Example 2) Equaling start
b003
Start 0Hz regardless of the motor speed.
On 0Hz start, the retry wait time is disregarded.
When 0Hz start is used and the motor speed is
still high there is the possibility of over-current
trips.
After FRS terminal is switched OFF, the Inverter
reads the frequency of the motor and when it
reaches the value in b007 the Inverter will begin to
RUN again.
On frequency matching start if an over-current trip
occurs, try extending the retry time.
