Option Description; Contents Of This Chapter; Overview - ABB ACS880-07 User Manual

Option description 15

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Option description

Contents of this chapter

This chapter describes the option +Q950, prevention of unexpected start-up, and its settings.

Overview

The option +Q950 uses the FSO-12 safety functions module (option +Q973) or the FSO-21
safety functions module (option +Q972) for the Prevention of unexpected start-up (POUS)
safety function. ABB installs the FSO module to the drive and sets default parameter values
for the option at the factory.
The user must install and connect an operating switch and an indication lamp (optional) on
site. These are not included in the delivery. The user can install the operating switch on, for
example, a control desk. See the machine-specific C-type standards on whether the indication
lamp is required.
When the user sets the operating switch to the open position, the POUS function activates
the Safe torque off (STO) function in the drive. The Safe torque off function disables the
control voltage of the power semiconductors of the drive output stage. This prevents the
drive from generating the torque required to rotate the motor. With the POUS function, the
user can do short-time operations (like cleaning) or maintenance work on the non-electrical
parts of the machinery without switching off and disconnecting the drive.
Note: The situations in which you can use the POUS function must always be based on a
risk assessment. Refer to IEC 60204-1:2016.