Mitsubishi Electric FR-D720-0.2K-G Instruction Manual page 263

Causes and corrective actions
Operation panel
E.ILF
indication
Name
Input phase loss
Drive unit trips when function valid setting (=1) is selected in Pr. 872 Input phase loss protection selection and one phase
of the three phase power input is lost. (Refer to page 145.)
Description
It may function if phase-to-phase voltage of the three-phase power input becomes largely unbalanced.
When the setting of Pr. 872 Input phase loss protection selection is the initial value (Pr. 872 ="0"), this warning does not
occur.
 Check for a break in the cable for the three-phase power supply input.
Check point
 Check that phase-to-phase voltage of the three-phase power input is not largely unbalanced.
 Wire the cables properly.
 Repair a break portion in the cable.
Corrective action
 Check the Pr. 872 Input phase loss protection selection setting.
 Set Pr. 872 = "0" (without input phase loss protection) when three-phase input voltage is largely unbalanced.
Operation panel
E.OLT
indication
Name
Stall prevention stop
If the rotation speed has fallen to 15r/min by stall prevention operation and remains for 3s, a fault (E.OLT) appears
Description and the drive unit trips. OL appears while stall prevention is being activated.
E.OLT may not occur if stall prevention (OL) is activated during output phase loss.
Check point
Check the motor for use under overload. (Refer to page 84.)
Corrective action
Reduce the load weight. (Check the Pr. 22 Stall prevention operation level setting.)
Operation Panel
E.SOT
Indication
Name
Loss of synchronism detection
Description
Stops the output when the operation is not synchronized.
 Check that the PM motor is not driven overloaded.
 Check if a start command is given to the drive unit while the PM motor is coasting.
Check point
 Check if a motor other than the PM motor (S-PM geared motor) is driven.
 Check that the operation is performed with a motor connected.
 Set the acceleration time longer.
 Reduce the load.
Corrective
 Input a start command after the motor stops.
action
 When driving a PM motor other than the S-PM geared motor, offline auto tuning must be performed. (Refer to page
105.)
 Check the connection of the PM motor. Set the PM motor test operation. (Refer to page 77.)
Operation panel
E.BE
indication
Name Brake transistor alarm detection
When a brake transistor alarm has occurred due to the large regenerative energy from the motor etc., the brake
transistor alarm is detected and the drive unit trips.
Description
In this case, the drive unit must be powered OFF immediately.
 Reduce the load inertia.
Check point
 Check that the frequency of using the brake is proper.
 Check that the brake resistor selected is correct.
Corrective action
Replace the drive unit.
Operation panel
E.GF
indication
Name
Output side earth (ground) fault overcurrent at start
The drive unit trips if an earth (ground) fault overcurrent flows at start due to an earth (ground) fault that occurred on
the drive unit's output side (load side). Whether this protective function is used or not is set with Pr. 249 Earth (ground)
Description
fault detection at start. When the setting of Pr. 249 Earth (ground) fault detection at start is the initial value (Pr. 249 =" 0 " ) ,
this warning does not occur.
Check point Check for a ground fault in the motor and connection cable.
Corrective action Remedy the ground fault portion.
260
FR-PU07 Input phase loss
FR-PU07 Stll Prev STP
FR-PU07 Motor step out
FR-PU07 Br. Cct. Fault
FR-PU07 Ground Fault