8. Maintenance and Inspection
8-3
8-3 Protective functions
The VAT2000 has the protective functions shown in Table 8-3.
Table 8-3 Protective function
Name
Function
Overcurrent trip
(OC-1 to 9)
The output is cut off and the inverter stops if the instantaneous value of the
output current exceeds the preset value.
Overvoltage trip
(OV-1 to 9)
The output is cut off and the inverter stops if the instantaneous value of the DC
voltage in the main circuit exceeds the preset value.
Undervoltage trip
(UV-1 to 9)
The output is cut off and the inverter stops if the DC voltage drops to approx.
65% or less due to a power failure or voltage drop during operation.
Overcurrent limit
If an overload occurs, the output frequency is automatically adjusted so that the
output current is less than the overcurrent limit (150% as a standard) set with
B18-0.
Overvoltage limit
If the output frequency is reduced suddenly, the DC voltage will rise in the main
circuit due to the regenerative power. The output frequency will be automatically
adjusted to prevent the DC voltage in the main circuit from exceeding the preset
value.
Overload trip
(OL-1)
The output will be cut off and the inverter will stop if the overload characteristics
set with C22-0, 1 and 2 are exceeded.
The setting (150% for 1 min. as a standard) can be changed according to the
characteristics of the motor.
Overheat
(UOH)
A thermistor is installed to detect temperature rises of the heatsink.
Self-diagnosis
(IO, dER, CPU)
The built-in CPU, peripheral circuits and data are tested and monitored for
abnormalities.
Grounding trip
(Grd1 to 9)
The output will be cut off and the inverter will stop if a ground fault is detected.
Power module fault
(PM-1 to 9)
The operation of the main circuit power module protection function is detected,
and the inverter will stop if a fault is detected.
