Alarm Detection - YASKAWA Varispeed G7 Series 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
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.
• The main circuit DC voltage was
UV
below the Undervoltage Detection
(blinking)
DC Bus Level Setting (L2-05).
Undervolt
• The surge current limiting mag-
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
Cooling Fin Overheating
(blinking)
The temperature of the Inverter's cool-
Heatsink
ing fins exceeded the setting in L8-02.
Overtemp
Inverter's Cooling Fan Fault
FAN
An Inverter's cooling fan fault was
(blinking)
detected.
Cooling
This fault is detected when L8-32 is
Fan Fault
set to 0.
Inverter Overheating Pre-alarm
OH2
An OH2 alarm signal (Inverter over-
(blinking)
heating alarm signal) was input from a
Over Heat
multi-function input terminal (S3 to
2
S7).
-16
7
Table 7.3 Alarm Displays and Processing
Meaning
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.
Probable causes
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 previ-
ous 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
• Check the resistance and wiring
Replace the cooling fan. (Contact
our sales representative.)
Clear the multi-function input ter-
–
minal's overheating alarm input.
Corrective Actions
has not been done.
for the frequency setting potenti-
ometer, etc. (Check that the cur-
rent for terminals +V and –V is
20 mA or less.)