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 FunctionName 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
Validfor inputs:C001~C005
Requiredsettings (none)
Notes:
xNote that when a USP error occurs and it is
canceled by a reset from a [RS] terminal input,
the inverter restarts running immediately.
xEven 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.
xWhen 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.
54321L
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

420

Operations and
Monitoring
4 20
Operations and
Monitoring