Unattended Start Protection
If the Run command is already set when power is turned ON, the inverter starts
running immediately after powerup. The Unattended Start Protection
(
USP
)
function
prevents that automatic startup, so that the inverter
will not run without outside
intervention. When USP is active and you need to reset an alarm and resume running,
either turn the Run command OFF, or perform a reset operation by the terminal
[
RS
]
input or the keypad Stop/reset key.
In the figure below, the
[
USP
]
feature is enabled. When the inverter power turns ON,
the motor does not start, even though the Run command is already active. Instead, it
enters the USP trip state, and displays E13 error code. This requires outside
intervention to reset the alarm by turning OFF the Run command per this example
(
or
applying a reset
)
. Then the Run command can turn ON again and start the inverter
output.
Option
Code
Terminal
Symbol
Function Name
State
Description
ON
On powerup, the inverter will not resume a Run
command
(
mostly used in the US
)
13
USP
Unattended Start
Protection
OFF
On powerup, the inverter will resume a Run
command that was active before power loss
Valid for inputs
:
C001~C005
Required settings
(
none
)
Notes
:
x
Note that when a USP error occurs and it is
canceled by a reset from a
[
RS
]
terminal input,
the inverter restarts running immediately.
x
Even when the trip state is canceled by turning
the terminal
[
RS
]
ON and OFF after an under
voltage protection E09 occurs, the USP function
will be performed.
x
When the running command is active
immediately after the power is turned ON, a
USP error will occur. When this function is
used, wait for at least three
(
3
)
seconds after the
powerup to generate a Run command.
Example (default input configuration shown for
–FU models; –FE and –FR models require input
configuration—see
page 3–49
):
See I/O specs on
page 4–6.
5
4
3
2
1
L
PCS P24
USP
Inverter output frequency
0
t
Inverter power supply
1
0
Alarm output terminal
1
0
[USP] terminal
1
0
Run command [FW,RV]
1
0
Events:
E13
Alarm
cleared
Run
command
4
20
Operations and
Monitori
ng
4
−
20
Operations and
Monitoring
