Mitsubishi Electric FR-A800 Series Instruction Manual page 786

 Alarm
Output is not shut off when a protective function is activated. The Alarm (LF) signal can be output depending on the parameter
setting. (Set "98" in Pr.190 to Pr.196 (Output terminal function selection). Refer to
Operation panel
indication
Name
Description
Check point
Corrective action
Operation panel
indication
Name
Description
Check point
Corrective action
 Fault
When a protective function is activated, the inverter output is shut off and a Fault signal is output.
Operation panel
indication
Name
Description
Check point
Corrective action
*1 Differs according to ratings. The rating can be changed using Pr.570 Multiple rating setting. (Refer to
148% for SLD rating, 170% for LD rating, 235% for ND rating (initial setting), and 280% for HD rating
Downloaded from ManualsNet.com
FN
Fan alarm
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.
When the cooling fan is replaced, check that the fan is not installed upside down.
Check the cooling fan for a failure.
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.
FN2
Internal fan alarm (IP55 compatible models only)
FN2 appears on the operation panel when the internal air circulation fan stops due to a fault or low rotation speed.
Check the internal air circulation fan for a failure.
The fan may be faulty. Contact your sales representative.
E.OC1
Overcurrent trip during acceleration
When the inverter output current reaches or exceeds approximately 235%
acceleration, the protection circuit is activated and the inverter output is shut off.
• 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 operation is
disabled.
• Check that the regenerative driving is not performed frequently. (Check if the output voltage becomes larger
than the V/F reference voltage at regenerative driving and overcurrent occurs due to increase in the motor
current.)
• Check that the power supply for RS-485 terminal is not shorted (under Vector control).
• Check that the encoder wiring and the specifications (encoder power supply, resolution, differential/
complementary) are correct. Check also that the motor wiring (U, V, W) is correct (under Vector control).
• Check that the rotation direction is not switched from forward to reverse rotation (or from reverse to forward)
during torque control under Real sensorless vector control.
• Check that the inverter capacity matches with the motor capacity. (PM sensorless vector control)
• Check if a start command is given to the inverter while the motor is coasting. (PM sensorless vector control)
• 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 appears,
contact your sales representative.
• 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
431.)
• Set the base voltage (rated voltage of the motor, etc.) in Pr.19 Base frequency voltage. (Refer to
• Check RS-485 terminal connection (under Vector control).
• Check the wiring and specifications of the encoder and the motor. Perform the setting according to the
specifications of the encoder and the motor (under vector control). (Refer to
• Prevent the motor from switching the rotation direction from forward to reverse (or from reverse to forward)
during torque control under Real sensorless vector control.
• Choose inverter and motor capacities that match. (PM sensorless vector control)
• Input a start command after the motor stops. Alternatively, use the automatic restart after instantaneous power
failure/flying start function. (Refer to
search engine
FR-LU08 indication FN
page 815.)
FR-LU08 indication FN2
FR-LU08 indication OC During Acc
page 707.)
page 635.) (PM sensorless vector control)
page 473.)
*1
of the rated current during
page 87.)
page 343.)
6. PROTECTIVE FUNCTIONS
6.5 Causes and corrective actions
1
2
3
4
5
6
7
8
9
10
page
page 707.)
785