
PROTECTIVE FUNCTIONS
133
(3) Warnings
FR-PU04 Indication
OL
Name
Stall prevention (overcurrent)
During
acceleration
If a current of more than 150%
Note 4
of the
rated inverter current flows in the motor, this
function stops the increase in frequenc
until the
overload current reduces to prevent the inverter
from resultin
in overcurrent shut-off. When the
overload current has reduced below 150%, this
function increases the frequency again.
During
constant-speed
operation
If a current of more than 150%
Note 4
of the
rated inverter current flows in the motor, this
function lowers the frequenc
until the overload
current reduces to prevent overcurrent shut-off.
When the overload current has reduced below
150%, this function increases the frequenc
up to
the set value.
Description
During
deceleration
If a current of more than 150%
Note 4
of the
rated inverter current flows in the motor, this
function stops the decrease in frequenc
until the
overload current reduces to prevent the inverter
from resultin
in overcurrent shut-off. When the
overload current has reduced below 150%, this
function decreases the frequency again.
Check point
Check the motor for use under overload.
Corrective action
The acceleration/deceleration time may change.
Increase the stall prevention operation level with Pr. 22 "stall
prevention operation level", or disable stall prevention with Pr. 156
"stall prevention operation selection".
Note:4 The stall prevention operation current can be set as desired. It is factory-set to
150%.
FR-PU04 Indication
oL
Name
Stall prevention (overvoltage)
Description
During
deceleration
If the re
enerative ener
of the motor increases
too much to exceed the brake capabilit
, this
function stops the decrease in frequenc
to
prevent overvolta
e shut-off. As soon as the
re
enerative ener
has reduced, deceleration
resumes.
Check point
Check for sudden speed reduction.
Corrective action
The deceleration time ma
chan
e. Increase the deceleration time
using Pr. 8 "deceleration time".
FR-PU04 Indication
PS
Name
PU stop
Description
A stop made by pressing the
STOP
RESET
key of the PU has been set in
Pr. 75 "PU stop selection".
Check point
Check for a stop made by pressing the
STOP
RESET
key of the PU during
DeviceNet operation.
Corrective action
Refer to page 88.