Mitsubishi Electric 800 Series Instruction Manual page 576

Abbreviation LDF
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.
 Alarm
Output is not shut off when a protective function activates. An alarm can also be output with a parameter setting.
(Set "98" in Pr.190 to Pr.196 (Output terminal function selection). (Refer to
Abbreviation FN
Name Fan alarm
Description For the inverter that contains a cooling fan, FN appears on the operation panel when the cooling fan stops due
to a fault, low rotation speed or different operation from the setting of Pr.244 Cooling fan operation selection.
Check point When the cooling fan is replaced, check that the fan is not installed upside down.
Check the cooling fan for a failure.
Corrective action Install the fan correctly. (Refer to
If the fan alarm still occurs after the fan is installed correctly, the fan may be faulty. Contact your sales
representative.
 Fault
When a protective function activates, the inverter trips and a fault signal is output.
Abbreviation E.OC1
Name Overcurrent trip during acceleration
Description When the inverter output current reaches or exceeds approximately 170% (LD rating) / 148% (SLD rating) of
the rated current during acceleration, the protection circuit is activated and the inverter trips.
Check point • Check for sudden speed acceleration.
• Check if the downward acceleration time is too long in a lift application.
• Check for output short-circuit.
• Check that the Pr.3 Base frequency setting is not 60 Hz when the motor rated frequency is 50 Hz.
• Check if the stall prevention operation level is set too high. Check if the fast-response current limit
• Check that the regenerative driving is not performed frequently. (Check if the output voltage becomes
• Check that the inverter capacity matches with the motor capacity. (PM motor control)
• Check if a start command is given to the inverter while the motor is coasting. (PM motor control)
Corrective action • Set the acceleration time longer. (Shorten the downward acceleration time of the lift.)
• If "E.OC1" always appears at start, disconnect the motor once and restart the inverter. If "E.OC1" still
• Check the wiring to make sure that output short circuit does not occur.
• Set 50 Hz in Pr.3 Base frequency. (Refer to
• Lower the stall prevention operation level. Activate the fast-response current limit operation. (Refer to
• Set the base voltage (rated voltage of the motor, etc.) in Pr.19 Base frequency voltage. (Refer to
• Choose inverter and motor capacities that match. (PM motor control)
• Input a start command after the motor stops. (IPM motor control)
page
operation is disabled.
larger than the V/F reference voltage at regenerative driving and overcurrent occurs due to increase in the
motor current.)
appears, contact your sales representative.
257.)
539.)
FR-LU08 LDF
FR-PU07
page 297.)
FR-LU08 FN
FR-PU07
600.)
FR-LU08 OC During Acc
FR-PU07
page 539.)
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6. PROTECTIVE FUNCTIONS
6.4 Causes and corrective actions
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