Mitsubishi Electric FR-F820-00077 Instruction Manual page 826

Causes and corrective actions
Operation panel
indication
Name
Description
Check point
Corrective action
Operation panel
indication
Name
Description
Check point
Corrective action
Operation panel
indication
Name
Description
Check point
Corrective action
Operation panel
indication
Name
Description
Check point
Corrective action
6 - 14
oL
Stall prevention (overvoltage)
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.
If the regenerative power of the motor becomes excessive to exceed the
regenerative power consumption capability, this function stops
During deceleration
decreasing the frequency to prevent overvoltage trip. As soon as the
regenerative power has reduced, deceleration resumes.
Check for sudden speed reduction.
Check if the regeneration avoidance function (Pr. 882 to Pr. 886) is being used.
(Refer to page 5-560.)
The deceleration time may change. Increase the deceleration time using Pr. 8 "Deceleration
time".
TH
Electronic thermal relay function pre-alarm
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 for large load or sudden acceleration.
Check that the Pr. 9 setting is appropriate. (Refer to page 5-150.)
Reduce the load and frequency of operation.
Set an appropriate value in Pr. 9. (Refer to page 5-150.)
PS
PU stop
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 for a stop made by pressing STOP/RESET key of the operation panel.
Turn the start signal OFF and release with PU/EXT key.
CP
Parameter copy
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.
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.
Set the initial value in Pr. 989 "Parameter copy alarm release".
Protective functions
FR-LU08 oL
FR-LU08 TH
FR-LU08 PS
FR-LU08 CP