Yaskawa G7 Drive - Manual (Page 390)

Protective and Diagnostic Functions
7-
9
‹ Alarm Detection
Alarms are detected as a type of Drive protection function that do not operate the fault contact output. The sys-
tem will automatically returned to its original status once the cause of the alarm has been removed.
The Digital Operator display flashes and the alarm is output from 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
EF
(blinking)
External
Fault
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.
UV
(blinking)
DC Bus
Under-
volt
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.
OV
(blinking)
DC Bus
Overvolt
Main Circuit Overvoltage
The main circuit DC voltage exceeded
the overvoltage detection level.
200-240 V class: Approx. 400 V
380-380 V class: Approx. 800 V
The power supply voltage is too high.
Decrease the voltage so it's within
specifications.
OH
(blinking)
Heat-
sink
Over-
temp
Cooling Fin Overheating
The temperature of the Drive's cooling
fins 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 Drive cooling fan has stopped.
Replace the cooling fan. (Contact your
Yaskawa representative.)
OH2
(blinking)
Over
Heat 2
Drive Overheating Pre-alarm
An OH2 alarm signal (Drive overheat-
ing alarm signal) was input from a
multi-function input terminal (S3 to
S12).
-
Clear the multi-function input termi-
nal's overheating alarm input.
OH3
(blinking)
Motor
Over-
heat 1
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, decelera-
tion, and cycle times.
Check the V/f characteristics.
Check the motor temperature input on
terminals A1 and A2.