6 Protective Function
6-1
FVR-C11S-EN
6
6 Protective Function
6-1 List of protec-
tive functions
When the protective function is activated, inverter output is instantly cut
off (while the motor coasts until it is stopped), and an alarm is issued,
and the details of the alarm are displayed on the keypad panel.
Alarm Name
Keypad
panel
display
Contents of operation
Overcurrent
OC1
During
acceleration
If the inverter output current momentarily ex-
ceeds the overcurrent detection level because of
an overcurrent in the motor or the short-circuit in
the output circuit, the output is shut down, an
alarm is issued, and the inverter is tripped.
OC2
During
deceleration
OC3
While running at
constant speed
Overvoltage
OU1
During
acceleration
If the DC voltage of the main circuit exceeds the
overvoltage detection level because of an in-
crease in the regenerating current from the mo-
tor, etc., output is shut down, an alarm is issued,
and the inverter is tripped. However, protection
against inadvertent overvoltage loading (e.g.
high-voltage line) might not be provided.
OU2
During
deceleration
OU3
While running at
constant speed
Undervoltage
LU
If the DC voltage of the main circuit falls below the undervoltage de-
tection level because of a lowered power supply, output is shut down
to protect the inverter. If the restart function after momentary power
failure is not activated, an alarm is issued and the inverter is tripped.
If the restart function is activated, the inverter restarts automatically
with no alarm.
For further details of the protective function, refer to the descriptions
of Function F14.
Overheating of
heat sink
OH1
If the temperature of the heat sink used for cooling the rectifier diodes
and IGBTs rises because of cooling fan failure, etc., protective func-
tion is activated to stop operation, an alarm is issued, and the inverter
is tripped.
