Mitsubishi Electric FR-E700EX Instruction Manual page 271

Operation panel
Err.
indication
Name Drive unit reset
 Executing reset using RES signal, or reset command from communication or PU
Description
 Displays at powering OFF.
Corrective
 Turn OFF the reset command
action
(2) Warnings
When a warning occurs, the output is not shut off.
Operation panel
OL
indication
Name Under torque limit
During
acceleration
During
Description
constantspeed
operation
During
deceleration
 Any of the acceleration time set by Pr.7 Acceleration time, deceleration time set by Pr.8 Deceleration time, and
positioning acceleration/deceleration time set by Pr.578 to Pr.591 is too short.
 Check for torque shortage in a low-speed range.
Check point
 Check if the acceleration/deceleration time in a low-speed range is too short.
 Check that the load is not too heavy.
 Are there any failure in peripheral devices?
 Check that the Pr.22 Torque limit level is appropriate
 Set a larger value in Pr.7 Acceleration time, Pr.8 Deceleration time, and positioning acceleration/deceleration time set in
Pr.578 to Pr.591. (Refer to page 125)
 Set a larger value in Pr.785 PM control torque boost. (Refer to page 114)
 Set longer times in Pr.791 Acceleration time in low-speed range and Pr.792 Deceleration time in low-speed range. (Refer to
Corrective
page 125)
action
 Reduce the load weight.
 Set the torque limit operation current in Pr.22 Torque limit level. (The initial value differs according to the drive unit
capacity and the motor being used.) Acceleration/deceleration time may change. Increase the torque limit operation
level with Pr.22 Torque limit level, or disable the torque limit operation with Pr.156 Torque limit selection. (Operation at
OL occurrence can be selected using Pr.156.)
 Check the connection of the PM motor.
Operation panel
oL
indication
Name
Stall prevention
During
Description
deceleration
 Check for sudden speed reduction.
Check point
 Check that regeneration avoidance function (Pr.882, Pr.883, Pr.885, Pr.886) is used. (Refer to page 242)
Corrective
The deceleration time may change. Increase the deceleration time using Pr.8 Deceleration time.
action
FR-PU07 OL
When the output current of the drive unit exceeds the torque limit operation level (Pr.22 Torque limit
level and others), this function stops the increase in the speed until the overload current drops in
order to prevent the drive unit from tripping by overcurrent. The speed increases again after the
overload current drops lower than the torque limit operation level.
When the output current of the drive unit exceeds the torque limit operation level (Pr.22 Torque limit
level and others), this function decreases the speed until the overload current drops in order to
prevent the drive unit from tripping by overcurrent. The speed goes back to the set speed after the
overload current drops lower than the torque limit operation level.
When the output current of the drive unit exceeds the torque limit operation level (Pr.22 Torque limit
level and others), this function stops the decrease in the speed until the overload current drops in
order to prevent the drive unit from tripping by overcurrent. The speed decreases again after the
overload current drops lower than the torque limit operation level.
FR-PU07 oL
 If the regenerative energy of the motor becomes excessive to exceed the regenerative energy
consumption capability, this function stops the decrease in speed 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 242)
Causes and corrective actions
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