Mitsubishi Electric FR-A820-00046 (0.4K), Instruction Manual

Page: 1066 / 1218

Causes and corrective actions Protective functions
6 - 26
Operation panel
indication
E.LDN FR-LU08 Lower limit fault
Name Lower limit fault detection
Description
When the load falls below the lower limit fault detection range, the inverter trips. This protective
function is not available in the initial setting of Pr. 1491 (Pr. 1491 = "9999").
Check point
앫
Check if the equipment load is too light.
앫
Check that the load characteristics settings are correct.
Corrective action
앫
Inspect the equipment.
앫
Set the load characteristics (Pr. 1481 to Pr. 1487) correctly.
Operation panel
indication
E.BE FR-LU-08 Brake transistor err
Name Brake transistor alarm detection
Description
앫
The inverter trips if a fault due to damage of the brake transistor and such occurs in the
brake circuit.
In such a case, the power supply to the inverter must be shut off
immediately.
앫
Appears when an internal circuit fault occurred for separated converter types and IP55
compatible models.
Check point
앫
Reduce the load inertia.
앫
Check that the brake duty is proper.
Corrective action Replace the inverter.
Operation panel
indication
E.GF FR-LU-08 Ground Fault
Name Output side earth (ground) fault overcurrent
Description
The inverter trips if an earth (ground) fault overcurrent flows due to an earth (ground) fault that
occurred on the inverter's output side (load side).
Check point Check for an earth (ground) fault in the motor and connection cable.
Corrective action Remedy the earth (ground) fault portion.
Operation panel
indication
E.LF FR-LU-08 Output phase loss
Name Output phase loss
Description
The inverter trips if one of the three phases (U, V, W) on the inverter's output side (load side) is
lost.
Check point
앫
Check the wiring. (Check that the motor is normally operating.)
앫
Check that the capacity of the motor used is not smaller than that of the inverter.
앫
Check if a start command is given to the inverter while the motor is coasting.
(PM sensorless vector control)
Corrective action
앫
Wire the cables properly.
앫
Input a start command after the motor stops. Alternatively, use the automatic restart after
instantaneous power failure/flying start function (page 5-590).
(PM sensorless vector control)