User Documentation

Periodic inspections
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5. Periodic inspections
Periodic functional inspections are used to discover
non-visible and dangerous faults which cannot be
detected by the self-diagnostics. It is therefore
important to check the functionality of the SIL3 relay
with the proper frequency.
The operator must determine the type of tests and
the proper time intervals. The time intervals are
partly determined by the calculation of each
individual safety circuit of the system (the PFD
values).
The inspections should be carried out so that the
flawless operation of the safety functions in
conjunction with components can be proven.