Alarm Detection - Omron VARISPEED F7 User Manual

Alarm Detection

Alarms are Inverter protection function that do not operate the fault contact output. The system will automati-
cally return to its original status when the cause of the alarm has been removed.
During an alarm condition, the Digital Operator display flashes and an alarm output is generated at the multi-
function outputs (H2-01 to H2-03) if programmed
When an alarm occurs, take appropriate countermeasures according to the table below.
Display
EF
External Fault
(flashing)
UV
DC Bus Undervolt
(flashing)
OV
DC Bus Overvolt
(flashing)
7
OH
Heatsnk Overtmp
(flashing)
OH2
Over Heat 2
(flashing)
OH3
Motor Overheat 1
(flashing)
10
7-
Table 7.2 Alarm Detection
Meaning
Forward/Reverse Run Commands
Input Together
Both the forward and the reverse
run commands are input simulta-
neously for 500ms or more. This
alarm stops the motor.
DC Bus Undervoltage
The following conditions
occurred
The DC bus voltage was below
the Undervoltage Detection Level
Setting (L2-05).
The MC of the inrush current pre-
vention circuit opened.
The control power supply voltage
was below the CUV level.
UV Alarm is only detected when
the drive is in a stopped condition
DC Bus Overvoltage
The DC bus voltage exceeded the
overvoltage detection level.
200 V class: 410 VDC
400 V class: 820 VDC
OV Alarm is only detected when
the drive is in a stopped condition
Heatsink Overheat
The temperature of the Inverter's
cooling fin exceeded the tempera-
ture programmed in L8-02.
Enabled when L8-03 = 3
Overheat Alarm
An OH2 alarm signal is input
from a multi-function digital
input terminal (S3 to S7) that is
programmed to OH2 Alarm Sig-
nal Input (H1- = B)
Motor Overheating Alarm
Detected when the level at A2,
programmed for motor tempera-
ture (Thermistor input, H3-09 =
E), exceeds 1.17 V for the time
L1-05 and L1-03 = 3.
Probable causes
The external forward and reverse
command were input simulta-
neously.
For the probable causes please
have a look at UV1, UV2 and
UV3 in table 7.1.
The power supply voltage is too
high.
The ambient temperature is too
high.
There is a heat source nearby.
The Inverter cooling fan(s) has
stopped.
An external overheat condition
exists that was connected to one
of the multi-function input termi-
nals S3 to S7.
Overheating of the motor as mea-
sured by the motor thermistor.
Corrective Actions
Check external sequence
logic, so only one input is
received at a time.
For the corrective actions
please have a look at UV1,
UV2 and UV3 in table 7.1
Check the power supply and
decrease the voltage to meet
the Inverter's specifications
Check for dirt build-up on the
fans or heatsink.
Reduce the ambient tempera-
ture around the Inverter
Replace the cooling fan(s).
Check the external overheat
signal connected to the speci-
fied digital input.
Verify the parameter settings
in H1-
Recheck the cycle time and
the size of the load.
Recheck the accel and decel
times (C1- )
Recheck the V/f pattern
(E1- ).
Recheck the motor rated cur-
rent value (E2-01)