Mitsubishi Electric 800 Series, Instruction Manual, Page: 635 / 727

Causes and corrective actions
634
PROTECTIVE FUNCTIONS
Abbreviation MT1 to MT3
FR-LU08 MT1 to MT3
FR-PU07 MT

Name
Maintenance signal output 1 to 3
Description
Appears when the inverter's cumulative energization time reaches or exceeds the parameter set value. Set
the time until the MT is displayed using
Pr.504 Maintenance timer 1 warning output set time (MT1), Pr.687
Maintenance timer 2 warning output set time (MT2), and Pr.689 Maintenance timer 3 warning output
set time (MT3).
MT does not appear when the settings of Pr.504, Pr.687, and Pr.689 are initial values (9999).
Check point
The set time of maintenance timer has been exceeded. (Refer to page 266 .)
Corrective action
Take appropriate countermeasures according to the purpose of the maintenance timer setting.
Setting "0" in
Pr.503 Maintenance timer 1, Pr.686 Maintenance timer 2 , and Pr.688 Maintenance timer 3
clears the indication.

MT appears for all of MT1, MT2 and MT3.
Abbreviation UF
FR-LU08 UF
FR-PU07 —
Name
USB host error
Description
Appears when an excessive current flows into the USB A connector.
Check point
Check if a USB device other than a USB memory device is connected to the USB A connector.
Corrective action
• If a device other than a USB memory device is connected to the USB A connector, remove the device.
• Setting
Pr.1049 USB host reset = "1" or inverter reset clears the UF indication.
Abbreviation HP1 to HP3
FR-LU08 HP1 to HP3
FR-PU07 —
Name
Home position return error
Description
Appears when an error occurs during the home position return operation under position control. For the
details, refer to
page 218 .
Check point
Identify the cause of the error occurrence.
Corrective action
Check the parameter setting, and check that the input signal is correct.
Abbreviation CF
FR-LU08 CF
FR-PU07 —
Name
Continuous operation during communication fault
Description
Appears when the operation continues while an error is occurring in the communication line or
communication option (when
Pr.502 = "4").
Check point
• Check for a break in the communication cable.
• Check for communication option faults.
Corrective action
• Check the connection of communication cable.
• Replace the communication option.
Abbreviation LDF
FR-LU08 LDF
FR-PU07 —
Name
Load fault warning
Description
Appears when the load is deviated from the detection width set in Pr.1488 Upper limit warning detection
width or Pr.1489 Lower limit warning detection width .
Check point
• Check if too much load is applied to the equipment, or if the load is too light.
• Check that the load characteristics settings are correct.
Corrective action
• Inspect the equipment.
• Set the load characteristics (
Pr.1481 to Pr.1487 ) correctly.