Frequency Pull-In Start - Omron RX2 Series User Manual

7-5-4

Frequency Pull-in Start

To achieve these goals when the motor is idling due to a trip or terminal function, enable the frequency
pull-in function so that the inverter is started with the output frequency specified to each function.
Even if a motor residual voltage is lost, the inverter will restart at the frequency selected in [bb-47] Start
frequency selection for frequency pull-in restart.
When frequency pull-in with the V/f control is selected, the inverter starts with a suppressed output volt-
age during the time set for [bb-45] Frequency pull-in operation time (voltage). When sensorless vector
control, zero-speed range sensorless vector control, or vector control with sensor is selected, the fre-
quency is automatically pulled in while controlling the current.
If the current increases during frequency pull-in to exceed [bb-43] Restart level, the motor will
decelerate over the time set for [bb-44] Frequency pull-in operation time (frequency).
If the current rapidly increases during frequency pull-in to exceed [bb-46] Overcurrent suppression level
for frequency pull-in restart, the overcurrent suppression function will automatically set in.
(Ex.) How the frequency pull-in works
Power failure
factor
Output current
Inverter output
frequency
Motor speed
Lower limit
setting
[bb-42]
Precautions for Correct Use
• If the restart after free-run stop or the restart after reset is performed, the inverter will restart
after the retry wait time after instantaneous power failure/under-voltage has elapsed.
• The restart after free-run stop and the restart after reset will be performed when the operation
command is given.
• The frequency pull-in restart function can be used only for induced motor drive. In addition, if
[AA121] Control mode is set to other than the V/f control, restart may become unstable. In
this case, see 7-5-3 Frequency Matching Start on page 7-65.
High-function General-purpose Inverter RX2 Series User's Manual
Deceleration time set at [bb-44]
Frequency set at [bb-47]
Free-running
Restarting with frequency pull-in
Retry wait time
Frequency pull-in
restart level
[bb-43]
7 Advanced Settings
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