User Documentation

4 2714570000/01/12-2020
Scope and denitions
1.1 Scope
This safety manual applies to the safety relays
SCS 24VDC P1SIL3ES LL 2633940000
SCS 24VDC P1SIL3ES LL-T 2634010000
from the Weidmüller SAFESERIES product family.
Manufacturer:
Weidmüller Interface GmbH & Co KG
Klingenbergstraße 26
32758 Detmold
Germany
Certication body:
TÜV NORD CERT GmbH
Zertizierungsstelle
Maschinen
Benannte Stelle 0044
Langemarckstraße 20
45141 Essen
Germany
The safety relay fulls the safety integrity level 3
(SIL 3) for low demand mode of operation. The de-
vice is certied according to EN 61508:2010 and
may bear the following TÜV certication mark.
Certicate Registration No
44 207 13773719
1.2 Termsandabbreviations
SafetyIntegrityLevel(SIL):
Four discrete levels (SIL1 to SIL4). The higher the
safety integrity level of a safety-related system, the
lower the probability that it will not perform the re-
quired safety functions.
AverageProbabilityofFailureonDemand
(PFD
avg
):
Average probability of failure of a safety function
working in low demand mode of operation.
ProbabilityofFailureperHour(PFH):
VAverage probability of failure of a safety function
working in high demand or continuous mode of op-
eration.
SafeFailureFraction(SFF):
Percentage part of safe failures and dangerous de-
tected failures of a safety function or a sub-system
related to all failures.
HardwareFaultTolerance(HFT):
HFT = n means, that n+1 faults could cause a loss
of the safety function.
Lowdemandmodeofoperation:
Frequency of demands on a safety-related system
no greater than one per year and no greater than
twice the proof-test frequency.
1 Scope and denitions