Omron VARISPEED L7 User Manual

7-3
7
OV
DC Bus Overvolt
DC Bus Overvoltage
The DC bus voltage has exceeded the
overvoltage detection level.
Default detection levels are:
200 V class: 410 VDC
400 V class: 820 VDC
The deceleration time is set too short
and the regenerative energy from the
motor is too large.
Increase the deceleration time (C1-
02/04/06/08) or connect a braking
option.
The power supply voltage is too high.
Check the power supply and
decrease the voltage to meet the
inverter’s specifications.
The braking chopper / braking resistor
is not working.
Check the braking chopper / resis-
tor.
UV1
DC Bus Undervolt
DC Bus Undervoltage
The DC bus voltage is below the Und-
ervoltage Detection Level
(L2-05). The default settings are:
200V class: 190 VDC
400 V class: 380 VDC
The voltage fluctuations of the power
supply are too high.
Check the input voltage.
A momentary power loss occurred.
The terminal screws of the input power
supply are loose.
Check the wiring of the input termi-
nals.
An open-phase error occurred at the
input terminals.
Check the input voltage and the
wiring of the input terminals.
The acceleration time is set too short.
Extend the settings in
C1-01/03/05/07
Main Circuit MC Operation Failure
The MC stopped responding during
Inverter operation.
An error occurred in the inrush current
prevention circuit while the Inverter
was running.
Replace the Inverter.
UV2
CTL PS Undervolt
Control Power Supply Undervoltage
Undervoltage of the control circuit
while the Inverter was running.
External load was pulling down the
Inverter’s power supplies or there was
an internal short in the power/gate drive
board.
Remove all connection to the con-
trol terminals and cycle the power
to the Inverter.
Replace the Inverter.
UV3
MC Answerback
Inrush Current Prevention Circuit Fault
An overheating of the charging resistor
for the DC bus capacitors occurred.
The MC of the charging circuit did not
respond 10 sec. after the MC ON signal
has been output.
(Applicable Inverter Capacities
200 V class: 37 to 55 kW)
The contactor of the inrush current pre-
vention circuit is defective.
Cycle the power to the Inverter.
Replace the Inverter if the fault
continues to occur.
PF
Input Phase Loss
Main Circuit Voltage Fault
An unusual big ripple on the DC bus
voltage has been detected.
Only detected when L8-05=1 (enabled)
The wiring terminals for the input
power supply are loose.
Tighten the input terminal screws
A phase loss occurred in the input
power supply.
Check the power supply voltage
A momentary power loss occurred
The voltage fluctuation of the input
power supply is too high.
The voltage balance between the input
phases is bad.
LF
Output Phase Loss
Output Open-phase
An open-phase occurred at the Inverter
output.
The fault is detected when the output
current falls below 5% of the inverter
rated current and L8-07=1 (enabled)
There is a broken wire in the output
cable.
The motor winding is broken.
The output terminals are loose.
Reset the fault after correcting its
cause.
The motor has a capacity less than 5%
of the Inverter's maximum motor
capacity.
Check the motor and Inverter
capacity.
Table 7.1 Resetable Faults
Display Meaning Probable Causes Corrective Actions

Omron VARISPEED L7 Specifications

General

Brand	Omron
Model	VARISPEED L7
Category	Inverter
Language	English