Implementing The Prevention Of Unexpected Start Function - ABB ACS800-17LC Hardware Manual

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Implementing the Prevention of unexpected start function

The drive equipped with option +Q950 supports the Prevention of unexpected start
function according to standards IEC/EN 60204-1:1997; ISO/DIS 14118:1996 and
EN 1037:1996. The circuit conforms to EN 954-1, Category 3.
The Prevention of unexpected start function disables the control voltage of the
power semiconductors of the drive output stage, thus preventing the motor-side
converter from generating the voltage required to rotate the motor. By using this
function, short-time operations (like cleaning) and/or maintenance work on non-
electrical parts of the machinery can be performed without switching off the power
supply to the drive.
The operator activates the prevention of unexpected start function using a switch
mounted on a control desk. When the function is activated, the switch is opened, and
an indicator lamp will light.
WARNING! The prevention of unexpected start function does not disconnect the
voltage of the main and auxiliary circuits from the drive. Therefore maintenance work
on electrical parts of the drive can only be carried out after isolating the drive system
from the main supply.
Note: If a running drive is stopped by using the Prevention of unexpected start
function, the drive will cut off the motor supply voltage and the motor will coast to
stop.
For more information, see Wiring, start-up and operation instructions of safety
options (+Q950, +Q951, +Q952, +Q963, +Q964, +Q967 and +Q968) for ACS800
cabinet-installed drives (3AUA0000026238 [English]).
Planning the electrical installation