Functional Safety Components - ABB ACS580 Series Hardware Manual

264 Maintenance

Functional safety components

The mission time of functional safety components is 20 years which equals the
time during which failure rates of electronic components remain constant. This
applies to the components of the standard Safe torque off circuit as well as any
modules, relays and, typically, any other components that are part of functional
safety circuits.
The expiry of mission time terminates the certification and SIL/PL classification
of the safety function. The following options exist:
• Renewal of the whole drive and all optional functional safety module(s) and
components.
• Renewal of the components in the safety function circuit. In practice, this is
economical only with larger drives that have replaceable circuit boards and
other components such as relays.
Note that some of the components may already have been renewed earlier,
restarting their mission time. The remaining mission time of the whole circuit is
however determined by its oldest component.
Contact your local ABB service representative for more information.