Alarm Detection - YASKAWA Varispeed G7 Instruction Manual

Alarm Detection

Alarms are detected as a type of Inverter protection function that do not operate the fault contact output. The
system will automatically returned to its original status once the cause of the alarm has been removed.
The Digital Operator display blinks and an alarm is sent from the multi-function outputs (H2-01 to H2-05) if
selected.
When an alarm occurs, take appropriate countermeasures according to the table below.
Display Meaning
Forward/Reverse Run Commands
EF
Input Together
(blinking)
Both the forward and Reverse Run
External
Commands have been ON for more
Fault
than 0.5 s.
Main Circuit Undervoltage
The following conditions occurred
when there was no Run signal.
UV
• The main circuit DC voltage was
(blinking)
below the Undervoltage Detection
DC Bus
Level Setting (L2-05).
Under-
• The surge current limiting mag-
volt
netic contactor opened.
• The control power supply voltage
when below the CUV level.
Main Circuit Overvoltage
OV
The main circuit DC voltage exceeded
(blinking)
the overvoltage detection level.
DC Bus
200 V Class: Approx. 410 V
Overvolt
400 V Class: Approx. 820 V
OH
(blinking)
Cooling Fin Overheating
Heat-
The temperature of the Inverter's cool-
sink
ing fins exceeded the setting in L8-02.
Over-
temp
FAN
Inverter's Cooling Fan Fault
(blink-
An Inverter's cooling fan fault was
ing)
detected.
Cooling
This fault is detected when L8-32 is
Fan
set to 0.
Fault
Inverter Overheating Pre-alarm
OH2
An OH2 alarm signal (Inverter over-
(blinking)
heating alarm signal) was input from a
Over
multi-function input terminal (S3 to
Heat 2
S7).
Table 7.3 Alarm Displays and Processing
Probable causes
-
See causes for UV1, UV2, and UV3
faults in the previous table.
The power supply voltage is too high.
The ambient temperature is too high.
There is a heat source nearby.
The Inverter cooling fan has stopped.
• A short-circuit between +V, −V, and
AC terminals occurred.
• Overload in the control circuit ter-
minal.
The Inverter's cooling fan has
stopped.
-
Protective and Diagnostic Functions
Corrective Actions
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.
See corrective actions for UV1, UV2,
and UV3 faults in the previous table.
Decrease the voltage so it's within
specifications.
Install a cooling unit.
Remove the heat source
Replace the cooling fan. (Contact your
Yaskawa representative.)
• Make sure that incorrect wiring has
not been done.
• Check the resistance and wiring for
the frequency setting potentiometer,
etc. (Check that the current for ter-
minals +V and –V is 20 mA or less.)
Replace the cooling fan. (Contact our
sales representative.)
Clear the multi-function input termi-
nal's overheating alarm input.
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