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

Option description and instructions 11

2
Option description and
instructions

Contents of this chapter

This chapter describes the operation of the option +Q950: Prevention of unexpected start-
up and instructs how to wire and use it.

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 modules to the inverter units and sets
default parameter values for the option at the factory. The user installs and wires an
operating switch and an indication lamp (optional) on site. These are not included in the
delivery.
When safety pulse encoders are used in the safety application, also the FSE-31 pulse
encoder interface modules (option +L521) are installed in the inverter units. ABB installs
the FSE modules to the inverter units and sets the delivery configuration for the cabinet
safety option at the factory.
The user activates the POUS function with an operating switch mounted, for example, on
a control desk. When the switch is open (off), the POUS function is active and the POUS
indication lamp is on.
When the user switches off the POUS switch, he/she actually activates the Safe torque off
(STO) function in the inverter unit. The STO function disables the control voltage of the
power semiconductors of the inverter unit output stage. This prevents the inverter unit from
generating the torque required to rotate the motor(s). With this function, the user can do