schmersal PROTECT-PSC - Calculation example

Overview
1
Instruction Manual PROTECT-PSC
V 2.6R01 / 04.19
1–12
1.9 Calculation example
F
F
i
i
g
g
u
u
r
r
e
e
1
1
-
-
4
4
C
C
a
a
l
l
c
c
u
u
l
l
a
a
t
t
i
i
o
o
n
n
e
e
x
x
a
a
m
m
p
p
l
l
e
e
/
/
P
P
e
e
r
r
f
f
o
o
r
r
m
m
a
a
n
n
c
c
e
e
L
L
e
e
v
v
e
e
l
l
/
/
S
S
a
a
f
f
e
e
t
t
y
y
I
I
n
n
t
t
e
e
g
g
r
r
i
i
t
t
y
y
L
L
e
e
v
v
e
e
l
l
1.9.1 Performance Level
The PL of the entire system is calculated as follows:
PL
Low
= c
N
Low
= 1
Result according to Table 1-1 : PL = c
1.9.2 SIL with high demand rate
The SIL of the entire system is calculated as follows:
PFH = PFH
sensor
+ PFH
PROTECT-PSC
+ PFH
actuator
= 5.2 * 10
-6
/h + 1.5 *10
-8
/h + 2.6 * 10
-8
/h
= 5.2 * 10
-6
/h
Result according to Table 1-4 : SIL = 1
1.9.3 SIL with low demand rate
The SIL of the entire system is calculated as follows:
PFD = PFD
sensor
+ PFD
PROTECT-PSC
+ PFD
actuator
= 4.1 * 10
-3
+ 3.0 * 10
-4
+ 1.9 * 10
-4
= 4.6 * 10
-3
Result according to Table 1-3 : SIL = 2
Sensor
PL : c
PFH : 5.2 * 10
-6
/h
PFD : 4.1 * 10
-3
PROTECT-PSC
PL : e
PFH : 1.5 * 10
-8
/h
PFD : 3.0 * 10
-4
Actuator
PL : e
PFH : 2.6 * 10
-8
/h
PFD : 1.9 * 10
-4