Protective and Diagnostic Functions
7
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7
Alarm Detection
Alarms are detected as a type of Inverter protection function that does not operate the fault contact output. The
system will automatically return to its original status once the cause of the alarm has been removed.
The Digital Operator display flashes and the alarm is output at the multi-function outputs (H2-01 to H2-03).
When an alarm occurs, take appropriate countermeasures according to the table below.
Table 7.2 Alarm Displays and Processing
Display
Meaning
Probable causes
Corrective Actions
(blink-
ing)
Forward/Reverse Run Commands
Input Together
Both the forward and reverse run com-
mands have been ON for more than
0.5 s.
-
Check the sequence of the forward and
reverse run commands.
Since the rotational direction is
unknown, the motor will be deceler-
ated to a stop when this minor fault
occurs.
(blink-
ing)
Main Circuit Undervoltage
The following conditions occurred
when there was no Run signal.
• The main circuit DC voltage was
below the Undervoltage Detection
Level Setting (L2-05).
• The surge current limiting contactor
opened.
• The control power supply voltage
when below the CUV level.
See causes for UV1, UV2 and UV3
faults in the previous table.
See corrective actions for UV1, UV2
and UV3 faults in the previous table.
(blink-
ing)
Main Circuit Overvoltage
The main circuit DC voltage exceeded
the overvoltage detection level.
200 V class: Approx. 400 V
400 V class: Approx. 800 V
The power supply voltage is too high.
Decrease the voltage so it's within
specifications.
(blink-
ing)
Cooling Fin Overheating
The temperature of the Inverter's cool-
ing fin exceeded the setting in L8-02.
The ambient temperature is too high.
Install a cooling unit.
There is a heat source nearby.
Remove the heat source
The Inverter cooling fan has stopped.
Replace the cooling fan. (Contact your
OMRON representative.)
(blink-
ing)
Inverter Overheating Pre-alarm
An OH2 alarm signal (Inverter over-
heating alarm signal) was input from a
multi-function input terminal (S3 to
S7).
-
Clear the multi-function input termi-
nal's overheating alarm input.
(blink-
ing)
Motor overheating
E was set for H3-09 and the motor
temperature thermistor input exceeded
the alarm detection level.
The motor has overheated.
Check the size of the load and the
length of the acceleration, deceleration
and cycle times.
Check the V/f characteristics.
Check the motor temperature input on
terminals A1 and A2.
(blink-
ing)
Overtorque 1
There has been a current greater than
the setting in L6-02 for longer than the
setting in L6-03.
-
• Make sure that the settings in L6-02
and L6-03 are appropriate.
• Check the mechanical system and
correct the cause of the overtorque.
