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 E 13 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.

 

Run command [FW,RV]

1

 

 

 

 

 

 

 

0

 

 

 

 

 

[USP] terminal

1

 

 

 

 

 

 

 

0

 

 

 

 

 

Alarm output terminal

1

 

 

 

 

 

 

 

0

 

 

 

 

 

Inverter output frequency

0

 

 

 

 

 

 

 

 

 

 

 

 

Inverter power supply

1

 

 

 

 

 

 

 

0

 

 

 

t

 

 

Events:

 

E13

Alarm

Run

 

 

 

 

 

 

 

cleared

command

 

 

 

 

 

 

 

Option

Terminal

Function Name

State

 

Description

 

Code

Symbol

 

 

 

 

 

 

 

 

13

USP

Unattended Start

 

ON

On powerup, the inverter will not resume a Run

 

 

 

Protection

 

 

command (mostly used in the US)

 

 

 

 

 

OFF

On powerup, the inverter will resume a Run

 

 

 

 

 

 

command that was active before power loss

 

 

 

C001 C007

 

Example (default input configuration shown see

 

 

 

~

 

 

page 66):

 

 

 

(none)

 

 

Notes:

 

 

 

 

 

 

 

 

 

 

USP

 

Note that when a USP error occurs and it is

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

canceled by a reset from a [RS] terminal input, the

 

7

6

5

4

3

2

1

L

PLC

P24

 

 

inverter restarts running immediately.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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.

See I/O specs on page 21,22.

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.

 

 

34

Page 36
Image 36
Hitachi hitachi series inverter Unattended Start Protection, Option Terminal Function Name State Description Code Symbol