204
PROTECTIVE FUNCTIONS
Operation Panel
Indication
oL FR-PU04 oL
Name Stall prevention (overvoltage)
Description
During
deceleration
f the regenerative energy of the motor increases too much to
exceed the brake capability, this function stops the decrease in
frequency to prevent overvoltage shut-off. As soon as the
regenerative energy has reduced, deceleration resumes.
Check point Check for sudden speed reduction.
Corrective action
The deceleration time may change. Increase the deceleration time using Pr. 8
"deceleration time".
Operation Panel
Indication
PS FR-PU04 PS
Name PU stop
Description
A stop made by pressing the key of the PU has been set in Pr. 75 "PU
stop selection".
Check point Check for a stop made by pressing the key of the operation panel.
Corrective action Refer to page 108.
Operation Panel
Indication
RB FR-PU04 RB
Name Regenerative brake prealarm
Description
This alarm appears if the regenerative brake duty reaches 85% of the value set in
Pr. 70 "special regenerative brake duty".
Regenerative overvoltage (E.OV_) occurs if the regenerative brake duty reaches
100%.
Check point Check that the brake resistor is not used frequently.
Corrective action Increase the deceleration time.
Operation Panel
Indication
TH FR-PU04 TH
Name Electronic overcurrent protection prealarm
Description
This alarm appears if the cumulative value of the electronic overcurrent protection
reaches 85% of the preset level. If it reaches 100% of the preset level, motor
overload shutoff (E.THM) occurs.
Check point Check for large load or sudden acceleration.
Corrective action Reduce the load volume or the frequency of operation.
Operation Panel
Indication
Err.
Description
This alarm appears if:
• The RES signal is on.
• You attempted to set any parameter value in the external operation mode.
• You attempted to change the operation mode during operation.
• You attempted to set any parameter value outside its setting range.
• Normal communication cannot be made between the PU and inverter.
• You attempted to set any parameter value during operation
(while signal STF or STR is ON).
• You attempted to make parameter setting when Pr. 77 "parameter write disable
selection" has been set to disable parameter write.
Corrective action Perform operation correctly.
STOP
RESET
STOP
RESET
