Individual Functions
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PI Feedback Loss Detection
When performing PI control, be sure to use the PI feedback loss detection function. If PI feedback is lost, the
Inverter output frequency may accelerate to the maximum output frequency.
When setting b5-12 to 1 and the status of the PI feedback value detection level in b5-13 is insufficient and
continues for the time set in b5-14, a FbL (PI feedback reference lost) alarm will be displayed on the Digital
Operator and Inverter operation will continue.
When b5-12 is set to 2, a FbL (PI feedback reference lost) error alarm will be displayed on the Digital Opera-
tor, the error contact will operate and Inverter operation will be stopped.
The time chart for PI feedback loss detection (set b5-12 to 2) is shown below.
Fig 6.44 PI Feedback Loss Detection Time Chart
PI Sleep
The PI sleep function stops the Inverter when the PI target value falls below the sleep operation level (b5-15)
for the sleep operation time set in parameter b5-16 or longer. The inverter operation will resume, if the PI tar-
get value exceeds the sleep operation level for the time set in parameter b5-16 or longer.
When PI control is disabled, the PI sleep function is also disabled. When using the PI sleep function, select
decelerate to stop or coast to stop as the stopping method.
The PI sleep time chart is shown below.
Fig 6.45 PI Sleep Time Chart
PI feedback value
Time
Fbl detection
Loss detection
level
(b5-13)
Loss detection time
(b5-14)
Loss detection time’
(b5-14)
No Fbl
detection
PI target value
Internal run command
External run command
Operating
Operation status output
Run command has been input
Stopped
Sleep operation
level b5-15
Sleep operation
delay time
Sleep operation
delay time
Operation
