schmersal PROTECT-PSC - Page 19

Overview
1
Instruction Manual PROTECT-PSC
V 2.6R01 / 04.19
1–11
Either by means of the process (application) or by means of organisational
measures, it must be ensured that the safety function is requested at least once
per year.
Every element of the chain must satisfy all requirements (e.g. restrictions of the
safety integrity of the hardware due to the architecture) of the resultant SIL
In order to determine the SIL, the PFH or PFD factors of the chain (sensor 
PROTECT-PSC  actuator) must be added together depending on the operating
mode. The resultant SIL can be determined using the following tables.
 PFD
i
SIL
 10
-4
bis < 10
-3
3
 10
-3
bis < 10
-2
2
 10
-2
bis < 10
-1
1
T
T
a
a
b
b
l
l
e
e
1
1
-
-
3
3
O
O
p
p
e
e
r
r
a
a
t
t
i
i
n
n
g
g
m
m
o
o
d
d
e
e
w
w
i
i
t
t
h
h
l
l
o
o
w
w
d
d
e
e
m
m
a
a
n
n
d
d
r
r
a
a
t
t
e
e
 PFH
i
SIL
 10
-8
bis < 10
-7
3
 10
-7
bis < 10
-6
2
 10
-6
bis < 10
-5
1
T
T
a
a
b
b
l
l
e
e
1
1
-
-
4
4
O
O
p
p
e
e
r
r
a
a
t
t
i
i
n
n
g
g
m
m
o
o
d
d
e
e
w
w
i
i
t
t
h
h
h
h
i
i
g
g
h
h
d
d
e
e
m
m
a
a
n
n
d
d
r
r
a
a
t
t
e
e
/
/
c
c
o
o
n
n
t
t
i
i
n
n
u
u
o
o
u
u
s
s
d
d
e
e
m
m
a
a
n
n
d
d