Safety Analysis - Eaton PKZM0 /XTPR BC1NL Serie Handbuch

1 PKZM0-.../XTPR...BC1NL, PKZM0-...-T/XTPT...BC1NL motor-protective circuit-breakers

1.4 Safety analysis

The following safety functions were determined for
PKZM0-.../XTPR...BC1NL and PKZM0-...-T/XTPT...BC1NL:
"Switching off motor in case of overload via thermal release to avoid thermal
overheating of motor."
Following characteristics for functional safety for PKZM0-.../XTPR...BC1NL
and PKZM0-...-T/XTPT...BC1NL were determined due to field data from
experience and operational reliability and lifespan tests. The calculation was
carried out i.a. according EN 61508-2 / 7.4.4ff (Path 2
1oo1 consisting of Typ A subsystems and a Hardware Fault Tolerance (HFT)
of 0 and according IEC 62061 and EN ISO 13849.
EN IEC 61508 / EN IEC 62061 –
Operation mode with high or continuous demand (> 1/year)
Safety integrity level / SIL Claim Limit
Safe Failure Fraction (SFF)
Common Cause Failure (CCF)
Diagnostic Coverage (DC)
Frequency of dangerous failure per hour (PFH
EN IEC 61508 / EN IEC 62061 –
Operation mode with low demand (≤ 1/year)
Safety integrity level / SIL Claim Limit
Requirement for SIL 1 according to EN IEC 61508
Test interval
Safe Failure Fraction (SFF)
Common Cause Failure (CCF)
Diagnostic Coverage (DC)
Average probability of a dangerous failure when
safety function is on demand (PFD
User must check if relevant regulations and standards e.g. according
EN 50156 require a shorter test interval.
PKZM0-.../XTPR...BC1NL, PKZM0-...-T/XTPT...BC1NL 01/22 MN03402003Z-DE/EN www.eaton.com
)
D
)
avg
1.4 Safety analysis
), for the architecture
H
SIL 1 / SIL CL 1
25 %
not relevant because single channel system
0 %
-9
20.06 x 10
SIL 1 / SIL CL 1
-2 -1
≥ 10 up to < 10
1 year
25 %
not relevant because single channel system
0 %
• At an interval for the repeat test T1 of
12 month: PFD = 0.879 x 10
avg
• At an interval for the repeat test T1 of
36 month: PFD = 2.63 x 10
avg
-4
-4
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