Relevant Failure Modes; Fault Exclusions; Operation Delays; General Rules, Notes And Definitions - ABB ACS880 User Manual

Relevant failure modes


Internal failures of safety relays and STO. These failures are included in the PFH value of
the function.

Fault exclusions


Fault exclusions (not considered in the calculations):
•
any short and open circuits in the cables of the safety circuit
•
any short and open circuits in the cabinet terminal blocks of the safety circuits.

Operation delays


Total delay for the POUS function: less than 100 ms.

General rules, notes and definitions

Validation of the safety functions


You must do an acceptance test (validation) to validate the correct operation of safety
functions.

Validation procedure

You must do the acceptance test using the checklist given in section
acceptance test on page 16:
•
at initial start-up of the safety function
•
after any changes related to the safety function (wiring, components, safety function
related parameter settings etc.)
•
after any maintenance action related to the safety function.
The acceptance test must include at least the following steps:
•
you must have an acceptance test plan
•
you must test all commissioned functions for proper operation, from each operation
location
•
you must document all acceptance test.

Acceptance test reports

You must store the signed acceptance test reports in the logbook of the machine. The
report must include, as required by the referred standards:
•
a description of the safety application (including a figure)
•
a description and revisions of safety components that are used in the safety
application
•
a list of all safety functions that are used in the safety application
•
a list of all safety related parameters and their values
•
documentation of start-up activities, references to failure reports and resolution of
failures
•
the test results for each safety function, checksums, date of the tests and confirmation
by the test personnel.
You must store any new acceptance test reports performed due to changes or
maintenance in the logbook of the machine.
Option description and instructions 21
Start-up and