Mitsubishi Electric FR-E710W-0.1K, Instruction Manual

Page: 294 / 349

294
Causes and corrective actions
Operation panel
indication
oL
FR-PU04
FR-PU07
oL
Name Stall prevention (overvoltage)
Description
During
deceleration
If the regenerative energy of the motor becomes excessive to exceed the regenerative energy
consumption capability, this function stops the decrease in frequency to prevent overvoltage trip.
As soon as the regenerative energy has reduced, deceleration resumes.
If the regenerative energy of the motor becomes excessive when regeneration avoidance function
is selected (
Pr. 882 =1), this function increases the speed to prevent overvoltage trip.
(Refer to page 261).
Check point
Check for sudden speed reduction.
Check that regeneration avoidance function
(Pr. 882, Pr. 883, Pr. 885, Pr. 886) is used. (Refer to page 261).
Corrective action
The deceleration time may change. Increase the deceleration time using Pr. 8 Deceleration time .
Operation panel
indication
PS
FR-PU04
FR-PU07
PS
Name
PU stop
Description
Stop with of the PU is set in Pr. 75 Reset selection/disconnected PU detection/PU stop selection . (For Pr. 75 refer to
page 184 .)
Check point
Check for a stop made by pressing of the operation panel.
Corrective action
Turn the start signal OFF and release with .
Operation panel
indication
RB
FR-PU04
FR-PU07
RB
Name Regenerative brake prealarm
Description
Appears if the regenerative brake duty reaches or exceeds 85% of the Pr. 70 Special regenerative brake duty value.
When the setting of Pr. 70 Special regenerative brake duty is the initial value ( Pr. 70 = "0"), this warning does not occur. If
the regenerative brake duty reaches 100%, a regenerative overvoltage (E. OV_) occurs.
The RBP signal can be simultaneously output with the [RB] display. For the terminal used for the RBP signal output,
assign the function by setting "7 (positive logic) or 107 (negative logic)" in any of
Pr. 190 to Pr. 192 (output terminal
function selection) . (Refer to page 145).
Check point
Check that the brake resistor duty is not high.
Check that the
Pr. 30 Regenerative function selection and Pr. 70 Special regenerative brake duty settings are correct.
Corrective action
Increase the deceleration time.
Check that the
Pr. 30 Regenerative function selection and Pr. 70 Special regenerative brake duty settings.
Operation panel
indication
TH
FR-PU04
FR-PU07
TH
Name
Electronic thermal relay function prealarm
Description
Appears if the cumulative value of the Pr. 9 Electronic thermal O/L relay reaches or exceeds 85% of the preset level. If
it reaches 100% of the Pr. 9 Electronic thermal O/L relay setting, a motor overload trip (E. THM) occurs.
The THP signal can be simultaneously output with the [TH] display. For the terminal used for THP signal output,
assign the function by setting "8 (positive logic) or 108 (negative logic)" in any of
Pr. 190 to Pr. 192 (output terminal
function selection) . (Refer to page 145).
Check point
Check for large load or sudden acceleration.
Is the
Pr. 9 Electronic thermal O/L relay setting is appropriate? (Refer to page 116)
Corrective action
Reduce the load and frequency of operation.
Set an appropriate value in
Pr. 9 Electronic thermal O/L relay . (Refer to page 116)