Mitsubishi Electric FR-F820-00046, Instruction Manual

Page: 826 / 940

Causes and corrective actions Protective functions
6 - 14
Operation panel
indication
oL FR-LU08 oL
Name Stall prevention (overvoltage)
Description
When the output voltage of the inverter increases, the stall prevention (overvoltage)
function activates.
The regeneration avoidance function activates due to excessive regenerative power of the
motor. (Refer to page 5-560.)
The following section explains the stall prevention (overvoltage) function.
During deceleration
If the regenerative power of the motor becomes excessive to exceed the
regenerative power consumption capability, this function stops
decreasing the frequency to prevent overvoltage trip. As soon as the
regenerative power has reduced, deceleration resumes.
Check point
Check for sudden speed reduction.
Check if the regeneration avoidance function (Pr. 882 to Pr. 886) is being used.
(Refer to page 5-560.)
Corrective action
The deceleration time may change. Increase the deceleration time using Pr. 8 "Deceleration
time".
Operation panel
indication
TH FR-LU08 TH
Name Electronic thermal relay function pre-alarm
Description
Appears if the cumulative value of the electronic thermal O/L relay reaches or exceeds 85% of
the preset level of Pr. 9 "Electronic thermal O/L relay". If the value reaches 100% of Pr. 9 setting,
motor overload trip (E.THM) occurs.
Check point
Check for large load or sudden acceleration.
Check that the Pr. 9 setting is appropriate. (Refer to page 5-150.)
Corrective action
Reduce the load and frequency of operation.
Set an appropriate value in Pr. 9. (Refer to page 5-150.)
Operation panel
indication
PS FR-LU08 PS
Name PU stop
Description
The motor is stopped using STOP/RESET key under the mode other than the PU operation mode.
(To enable STOP/RESET key under the mode other than the PU operation mode, set Pr. 75 "Reset
selection/disconnected PU detection/PU stop selection". Refer to page 5-63 for details.)
Check point Check for a stop made by pressing STOP/RESET key of the operation panel.
Corrective action Turn the start signal OFF and release with PU/EXT key.
Operation panel
indication
CP FR-LU08 CP
Name Parameter copy
Description
Appears when parameter copy is performed between inverters FR-F820-02330(55K) or lower, FR-
F840-01160(55K) or lower, FR-F820-03160(75K) or higher and FR-F840-01800(75K) or higher.
Check point
Resetting of Pr. 9, Pr. 30, Pr. 51, Pr. 56, Pr. 57, Pr. 72, Pr. 80, Pr. 82, Pr. 90 to Pr. 94, Pr. 453, Pr. 455, Pr.
458 to Pr. 462, Pr. 557, Pr. 859, Pr. 860 and Pr. 893 is necessary.
Corrective action Set the initial value in Pr. 989 "Parameter copy alarm release".