Rockwell Automation Allen-Bradley POINT Guard - Page 183

Rockwell Automation Publication 1734-UM013J-EN-P - July 2014 183
Safety Data Appendix D
Figure 62 - PFD vs. Proof Test Interval 1734-OB8S Series A
Mission Time for all modules is 20 years.
PFD
Proof Test Interval [years]
Cat. No.
Proof Test Interval
(Mission Time)
PFD
PFH
(1/hour)
Spurious Trip Rate (STR)
(2)
(2) Calculated based on ISA TR-84 method.
MTTF
spurious
(3)
(years)
(3) Mean Time to Failure (Spurious).
Year Hour
1734-IB8S
Series A
1 8760 2.11E-06
5.10E-10 2.666E-06 42.78
2 17520 4.23E-06
5 43800 1.06E-05
10 87600 2.11E-05
20 175200 4.23E-05
1734-OB8S
Series A
1 8760 2.13E-06
5.14E-10 3.229E-06 35.33
2 17520 4.27E-06
5 43800 1.07E-05
10 87600 2.13E-05
20 175200 4.27E-05
1734-IE4S
Series A
1 8760 1.6E-07
3.7E-11
9.402E-07 121.42
2 17520 3.2E-07
5 43800 8.1E-07
10 87600 1.6E-06 3.8E-11
10
(1)
(1) This data is for dual channel mode of operation.
87600 2.4E-06 5.5E-11
20 175200 3.3E-06 3.9E-11