Chapter 8 Troubleshooting & Maintenances
8-1
8.1 Fault display
Caution
When a fault occurs, the inverter turns off its output and displays the fault status described below. In this
case, the cause must be corrected before the fault can be cleared. If protective function keeps active, it could
lead to reduction in product life and damage to the equipment.
Protective
function
Keypad
display
Description
Over Current
OC-U
OC-V
OC-W
The inverter turns off its output when the output current of the inverter flows
more than 200% of the inverter rated current.
Ground Fault
Protection
Ground Fault
The inverter turns off its output when a ground fault occurs and the ground
fault current is more than the internal setting value of the inverter. Over current
trip function may protect the inverter when a ground fault occurs due to a low
ground fault resistance
Over voltage
protection
Over Voltage
The inverter turns off its output if the DC voltage of the main circuit increases
higher than the rated value (400V class: 820 V dc) when the motor decelerates
or when regenerative energy flows back to the inverter due to a regenerative
load. This fault can also occur due to a surge voltage generated at the power
supply system.
Low Voltage
Protection
Low Voltage
The inverter turns off its output if the DC voltage is below the detection level
(400V class: 400Vdc) because insufficient torque or over heating of the motor
can occurs when the input voltage of the inverter drops.
Overload (trip)
Protection
Over Load
The inverter turns off its output if the output current of the inverter flows at
180% of the inverter rated current for more than the current limit time (S/W).
Inverter
overheat
InvOver Heat
The inverter turns off its output if the heat sink over heats due to a damaged
cooling fan or an alien substance in the cooling fan by detecting the
temperature of the heat sink.
Inverter NTC
Thermistor Open
InvThem OP
When inverter NTC Thermistor is open, inverter stops its output.
Motor overheat
MotOver
Heat
When motor temp exceeds 150
℃
, inverter stops its output to protect motor
from overheated.
Motor NTC
Thermistor Open
MotThem OP
When motor NTC Thermistor is open, inverter stops its output.
Electronic Thermal
E-Thermal
The internal electronic thermal of the inverter determines the over heating of
the motor. If the motor is overloaded the inverter turns off the output. The
inverter cannot protect the motor when driving a multi-pole motor or when
driving multiple motors, so consider thermal relays or other thermal protective
devices for each motor. Overload capacity: 180% for 1 min.
External fault B
Ext Trip-B
Use this function if the user needs to turn off the output by an external fault
signal.
IGBT Short
Arm Short-U
Arm Short-V
Arm Short-W
Arm Short-DB
Inverter output is stopped when IGBT Arm short or output short occurs.
Encoder error Encoder Err
Displayed when Encoder signal fault occurs.