Mitsubishi Electric 800 Series Instruction Manual page 27

 Upper limit fault detection
Operation panel
indication
The inverter output is shut off when the load exceeds the upper limit fault detection range. This protective
Description
function is not available in the initial setting of Pr.1490 (Pr.1490 = "9999").
• Check if too much load is applied to the equipment.
Check point
• Check that the load characteristics settings are correct.
• Inspect the equipment.
Corrective action
• Set the load characteristics (Pr.1481 to Pr.1487) correctly.
Reference FR-E800 Instruction Manual (Function)
 Lower limit fault detection
Operation panel
indication
The inverter output is shut off when the load falls below the lower limit fault detection range. This protective
Description
function is not available in the initial setting of Pr.1491 (Pr.1491 = "9999").
• Check if the equipment load is too light.
Check point
• Check that the load characteristics settings are correct.
• Inspect the equipment.
Corrective action
• Set the load characteristics (Pr.1481 to Pr.1487) correctly.
Reference FR-E800 Instruction Manual (Function)
 Brake transistor alarm detection
Operation panel
indication
• The inverter output is shut off if a fault due to damage of the brake transistor and such occurs in the brake
Description circuit.
In such a case, the power supply to the inverter must be shut off immediately.
• Reduce the load inertia.
Check point
• Check that the brake duty is proper.
Corrective action Replace the inverter.
 Output side earth (ground) fault overcurrent
Operation panel
indication
The inverter output is shut off if an earth (ground) fault overcurrent flows due to an earth (ground) fault that
Description
occurred on the inverter's output side (load side).
Check point Check for a ground fault in the motor and connection cable.
Corrective action Remedy the earth (ground) fault portion.
Reference FR-E800 Instruction Manual (Function)
 Output phase loss
Operation panel
indication
Description The inverter output is shut off if one of the three phases (U, V, W) on the inverter's output side (load side) is lost.
• Check the wiring. (Check that the motor is normally operating.)
Check point • Check that the capacity of the motor used is not smaller than that of the inverter.
• Check if a start command is given to the inverter while the motor is coasting. (PM sensorless vector control)
• Wire the cables properly.
Corrective action • Input a start command after the motor stops. Alternatively, use the automatic restart after instantaneous power
failure / flying start function. (PM sensorless vector control)
Reference FR-E800 Instruction Manual (Function)
E.LUP
E.LDN
E.BE
E.GF
E.LF
FR-LU08 indication Upper limit fault
FR-LU08 indication Lower limit fault
ER-LU08 indication Brake transistor err
FR-LU08 indication Ground Fault
FR-LU08 indication Output phase loss
2.5 Causes and corrective actions
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2. Protective Functions