Hitachi WJ Series

Chapter 9 Inverter Functions
9-7-9
9.7.6 Starting after Free Run Stop
 How to restart the inverter to match the rotation speed of the motor when idling after a free run
stop?
 The brakes are applied when stopping while the stopping method is set to free run stop. How to
start the inverter from 0 Hz?
 Use "Restart mode after FRS release [b088]" to choose either 0 Hz restart, frequency matching
restart
*1
, or active frequency matching restart
*2
as the starting method when the "Free run stop
[FRS](11)" terminal is turned from on to off.
 If the "STOP mode selection [b091]" is set to "Free run stop (01)", and the RUN command [OFF]
(stop command) is applied, the inverter enters the free run stop state, and the settings
configured in "Restart mode after FRS release [b088]" will apply the next time the inverter is in
operation. For details on "STOP mode selection [b091]", refer to "9.7.7 Selecting Stop
Operation".
 In case of a 0 Hz restart, there is no retry wait time setting.
 When performing the active frequency matching restart, the RUN command direction when
starting the active frequency matching operation is the same as the RUN command direction at
the time of reset input.
Code
Item
Description
Data
[b003]
Retry wait time after
instantaneous power
failure/undervoltage error
Sets the wait time from when the power returns
until the restart.
0.3 to 100.0 (s)
[b088]
Restart mode after FRS
release
Performs a 0 Hz restart.
00
Performs the frequency matching restart
(= Active frequency matching restart at the
frequency of the previous output interruption).
01
*1
Performs the active frequency matching restart.
02
*2
◼ (Example 1) Example of operation when the
"STOP mode selection [b091]" is
set to "Free run stop (01)"
◼ (Example 2) Example of operation when the [FRS]
terminal is turned on and off while the
inverter is stopped
◼ (Example 3) Example of operation when the
[FRS] terminal is turned on and off
during operation (b088 = 00)
Free running
Startup according
to [b088]
[b003]
Motor speed
RUN
command
ON
OFF
◼ (Example 4) Example of operation when the
[FRS] terminal is turned on and
off during operation (b088 ≠ 00)
[b088]=01: Frequency matching restart
[b088]=02: Active frequency matching restart
Free running
[b003]
Motor speed
RUN
command
Free run stop
[FRS]
ON
ON
Free run stop
[FRS]
RUN
command
Free running
Motor speed
0 Hz restart
ON
ON
ON
Free running
[b003]
Motor speed
RUN
command
Free run stop
[FRS]
ON
* Switch the free run stop [FRS] terminal from on to off while the
inverter is stopped, and then turn the RUN command on to
start operation according to the [b088] setting.
(In case of 0Hz restart, there is no wait time.)
A
!
Q