List Of Protective Operations - IMO VXSM75-1 Instruction Manual

6. Protective Operation
6-1

List of Protective Operations

When an error occurs to the inverter, a
protective function is activated to trip the
inverter immediately, displaying the name of the
alarm at the LED and allowing the motor to
coast to stop.
Name of alarm Display
Overcurrent OC1
protection
OC2
OC3
Overvoltage OU1
protection
OU2
OU3
Undervoltage LU
protection
Input phase Lin
loss
protection
Heat sink OH1
overheat
External OH2
alarm
input
Braking dbH
resistor
overheat
Motor 1
overload
Motor 2 OL2
overload
Inverter OLU
overload
Memory error Er1
Keypad panel Er2
communication
error
CPU error Er3
Option error Er4
Er5
Output phase Er7
loss
RS485 Er8
communication
error
Table 6-1-1 List of alarm display and protective operations
6-1
Description of operation
During The protective function is activated when an overcurrent flowing in
acceleration the motor or a short circuit or ground fault in the output circuit
During causes the instantaneous inverter output current to exceed the
deceleration overcurrent detection level.
During constant
speed operation
During The protective function is activated when the regenerative power from
acceleration the motor increases to cause the DC link voltage of the main circuit
During to exceed the overvoltage detection level (Approx. 400 Vdc for 200V
deceleration class, Approx. 800V for 400V class). When an excessive voltage is
During constant added to the source voltage, the inverter trips due to the overvoltage,
speed operation but inverter protection against the overvoltage is impossible.
The protective function is activated when the source voltage drops to cause the DC
link voltage in the main circuit to become lower than the undervoltage detection
level (Approx. 200 Vdc for 200V class, Approx. 400V for 400V class). If F14 Restart after
momentary power failure has been selected, no alarm display is given. If the voltage
drops below the control power maintenance level, no alarm is displayed.
When the inverter is operated while one of the three phases of the power supply
connected to the main power supply input terminals L1/R, L2/S and L3/T of the main
circuit is missing or there is an unbalance among the three-phase voltages, the rectifying
diode or smoothing capacitor of the main circuit may be broken. The inverter is stops
upon an alarm in these cases.
The protective function is activated when the temperature of the heat sink of the inverter
overheat is high because of a broken cooling fan or for other reasons.
The protective function is activated by a contact signal from an alarm contact of the
external device such as the braking unit, braking resistor, and external thermal overload
relay connected to the control circuit terminal (THR). Or an overheat protective function is
activated by the PTC thermistor.
If the electronic thermal overload relay (for braking resistor) has been selected for
function code F13, the protective function is activated upon a high operation frequency of
the braking resistor to prevent the resistor from being burned due to the temperature rise.
OL1 If electronic thermal overload relay 1 has been selected for function code F10, the
protective function is activated by a motor current exceeding the set operation level.
If motor 2 has been selected and driven and electronic thermal overload relay 2 has been
selected for function code A06, the protective function is activated by the current in motor
2 exceeding the set operation level.
The protective function is activated by an output current exceeding the overload current
rating to protect the semiconductor elements in the main circuit of the inverter from high
temperatures.
The protective function is activated by a data writing error or other errors in the memory.
The protective function is activated when a data transmission error or transmission
stoppage is detected between the keypad panel and the control section in the keypad
panel operation mode.
The protective function is activated by electric noise or other errors developed in the
CPU, or if P24 is overloaded.
Error during operation of option
The protective function is activated during auto tuning when there is a broken wire or no
connection in the inverter output circuit.
The protective function is activated when a communication error occurs during
communication through RS485.
Protective Operation