Mitsubishi Electric FR-D720-0.2K-G, Instruction Manual

Page: 259 / 302

256
Causes and corrective actions
Operation panel
indication
PS 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 157 .)
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-PU07 RB
Name
Regenerative brake pre-alarm
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
Pr. 190
or
Pr. 192 (output terminal function
selection)
.
(Refer to page 123.)
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-PU07 TH
Name
Electronic thermal relay function pre-alarm
Description
Appears when the accumulated electronic thermal value reaches 85% of the Pr.9 setting. When the accumulated
electronic thermal value reaches 100% of the Pr.9 setting, the protection circuit is activated and the drive unit is shut
off.
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
Pr. 190 or Pr. 192 (output terminal function
selection) . (Refer to page 123.)
Check point

Check for large load or sudden acceleration.

Is the
Pr. 9 Electronic thermal O/L relay
setting is appropriate?
(Refer to page 101.)
Corrective action
 Reduce the load and frequency of operation.
 Set the rated motor current in Pr. 9 Electronic thermal O/L relay . (Refer to page 101.)
Operation panel
indication
MT FR-PU07 MT
Name
Maintenance signal output
Description
Indicates that the cumulative energization time of the drive unit has reached a given time.
When the setting of
Pr. 504 Maintenance timer alarm output set time
is the initial value (
Pr. 504
= "9999"), this warning
does not occur.
Check point
The Pr. 503 Maintenance timer setting is larger than the Pr. 504 Maintenance timer alarm output set time setting. (Refer to
page 235.)
Corrective action Setting "0" in
Pr. 503 Maintenance timer
erases the signal.
Operation panel
indication
UV FR-PU07 ——
Name Undervoltage
Description
If the power supply voltage of the drive unit decreases, the control circuit will not perform normal functions. In
addition, the motor torque will be insufficient and/or heat generation will increase. To prevent this, if the power supply
voltage decreases below about 160VAC (about 320VAC for 400V class), this function stops the drive unit output and
displays .
An alarm is reset when the voltage returns to normal.
Check point
Check that the power supply voltage is normal.
Corrective action
Check the power supply system equipment such as power supply.