834-835 / 973
a CSA International company
FMEA of the (close/open)
Circuit type B wz diag.
No.
Values
Description
Component
Failure Rate
(λs)
Failure modes
factors / open
Failure modes types
/ short
Qty of
compts
safe=S
danger=D
no-effect=N
Diagnostic
Detect=Y
Undet=N
Redundanc
y ?
safe=S
danger=D
no-effect=N
Diagnostic
Detect=Y
Undet=N
IEC61508
Annex A,
D.coverage
Safe
Rev'led
Safe Un-
rvld
Dangrs
Detect
Dangrs Un-
detec
Safe
Rev'led
Safe Un-
rvld
Dangrs
Detect
Dangrs Un-
detec
Safe No-
effect
SOLENOID CONTROL BOARD
Open condition
Short condition
1 R1
Resistor
0.00041
0.9
0.1
1
s
no
No
d
yes
medium
0
0.00037
0
0
0
0
3.7E-05
4.1E-06
0
23 R23
Resistor
0.00041
0.9
0.1
1
s
yes
No
s
No
low
0.00037
0
0
0
0
4.1E-05
0
0
0
22 C1
Capacitor
0.0005
0.2
0.8
1
d
yes
No
d
yes
medium
0
0
0.00009
0.00001
0
0
0.00036
0.00004
0
26 D1
Diode
0.00725
0.8
0.2
1
s
no
No
s
yes
medium
0
0.0058
0
0
0.00145
0
0
0
0
32 Q1
MOSFET - N CHANNEL
0.0031
0.2
0.8
1
d
yes
No
d
yes
medium
0
0
0.00056
6.2E-05
0
0
0.00223
0.00025
0
43 IC4
BUFFER IC4B O/P
0.0086
0.033open
1
d
yes
No
n
No
medium
0
0
0.00026
2.8E-05
0
0
0
0
0.0086
0.0086
0.033short to +
1
d
yes
No
n
No
medium
0
0
0.00026
2.8E-05
0
0
0
0
0.0086
0.0086
0.033short to -
1
d
yes
No
n
No
medium
0
0
0.00026
2.8E-05
0
0
0
0
0.0086
0.0086
0.033short to pin above
1
n
no
No
n
No
no diagnostics
0
0
0
0
0
0
0
0
0.00888
0.0086
0.033short to pin below
1
s
no
No
n
No
no diagnostics
0
0.00028
0
0
0
0
0
0
0.0086
48
IC3
COMPARATOR SINGLE 1V6-5V5 PUSH-PULL - 3
0.0069
0.04open
1
d
no
No
n
No
no diagnostics
0
0
0
0.00028
0
0
0
0
0.0069
0.0069
0.04short to +
1
d
no
No
n
No
no diagnostics
0
0
0
0.00028
0
0
0
0
0.0069
0.0069
0.04short to -
1
d
no
No
n
No
no diagnostics
0
0
0
0.00028
0
0
0
0
0.0069
0.0069
0.04short to pin above
1
d
no
No
n
No
no diagnostics
0
0
0
0.00028
0
0
0
0
0.0069
0.0069
0.04short to pin below
1
d
no
No
n
No
no diagnostics
0
0
0
0.00028
0
0
0
0
0.0069
53
IC2
74LVC2G00 DUAL TWO INPUT NAND - 3 O/P MAIN
0.005
0.025open
1
d
yes
No
n
No
medium
0
0
0.00011
1.3E-05
0
0
0
0
0.005
0.005
0.025short to +
1
d
yes
No
n
No
medium
0
0
0.00011
1.3E-05
0
0
0
0
0.005
0.005
0.025short to -
1
d
yes
No
n
No
medium
0
0
0.00011
1.3E-05
0
0
0
0
0.005
0.005
0.025short to pin above
1
d
yes
No
n
No
medium
0
0
0.00011
1.3E-05
0
0
0
0
0.005
0.005
0.025short to pin below
1
d
yes
No
n
No
medium
0
0
0.00011
1.3E-05
0
0
0
0
0.005
60
uP
Microcontroller PIC12small controller - PIN 2 reset
0.0091
0.00714open
1
s
yes
No
n
No
medium
6.5E-05
0
0
0
0
0
0
0
0.0091
0.0091
0.00714short to +
1
s
yes
No
n
No
medium
6.5E-05
0
0
0
0
0
0
0
0.0091
0.0091
0.00714short to -
1
s
yes
No
n
No
medium
6.5E-05
0
0
0
0
0
0
0
0.0091
0.0091
0.00714short to pin above
1
n
no
No
n
No
no diagnostics
0
0
0
0
0
0
0
0
0.00916
0.0091
0.00714short to pin below
1
d
yes
No
n
No
medium
0
0
5.8E-05
6.5E-06
0
0
0
0
0.0091
uP
Microcontroller PIC12small controller - PIN 28 Open Coil FB
0.0091
0.00714open
1
s
yes
No
n
No
low
6.5E-05
0
0
0
0
0
0
0
0.0091
0.0091
0.00714short to +
1
s
yes
No
n
No
low
6.5E-05
0
0
0
0
0
0
0
0.0091
0.0091
0.00714short to -
1
s
yes
No
n
No
low
6.5E-05
0
0
0
0
0
0
0
0.0091
0.0091
0.00714short to pin above
1
s
yes
No
n
No
low
6.5E-05
0
0
0
0
0
0
0
0.0091
0.0091
0.00714short to pin below
1
s
yes
No
n
No
low
6.5E-05
0
0
0
0
0
0
0
0.0091
uP
Microcontroller PIC12small controller - UN-USED PINS
0.0091
0.5714NOT USED
1
n
no
No
n
No
no diagnostics
0
0
0
0
0
0
0
0
0.0143
61 sol
Thompson solenoid
0.0152
0.52short
1
d
yes
No
n
No
low
0
0
0.00474
0.00316
0
0
0
0
0.0152
0.0152
0.28sticking
1
d
yes
No
n
No
low
0
0
0.00255
0.0017
0
0
0
0
0.0152
0.0152
0.14spring failure
1
d
yes
No
n
No
low
0
0
0.00128
0.00085
0
0
0
0
0.0152
0.0152
0.06open
1
d
yes
No
n
No
low
0
0
0.00055
0.00036
0
0
0
0
0.0152
No. Values
Description
Component
Failure Rate
(λs)
Failure
modes
factors /
open
Failure modes
types / short
Qty of
compts
SOLENOID CONTROL BOARD
OPEN
SHORT
1
R1
Resistor
0.00041
0.9
0.1
1
23
R23
Resistor
0.00041
0.9
0.1
1
22
C1
Capacitor
0.0005
0.2
0.8
1
26
D1
Diode
0.00725
0.8
0.2
1
32
Q1
MOSFET - N CHANNEL
0.0031
0.2
0.8
1
43
IC4
BUFFER IC4B O/P
0.0086
0.033
open
1
0.0086
0.033
short to +
1
0.0086
0.033
short to -
1
0.0086
0.033
short to pin
above
1
0.0086
0.033
short to pin
below
1
safe=S
danger=D
no-effect=N
Diagnostic
Detect=Y
Undet=N
Redunda
ncy ?
safe=S
danger=D
no-effect=N
Diagnostic
Detect=Y
Undet=N
IEC61508
Annex A,
D.coverage
Open condition
Short condition
s
no
No
d
yes
medium
s
yes
No
s
No
low
d
yes
No
d
yes
medium
s
no
No
s
yes
medium
d
yes
No
d
yes
medium
d
yes
No
n
No
medium
d
yes
No
n
No
medium
d
yes
No
n
No
medium
n
no
No
n
No
no diagnostics
s
no
No
n
No
no diagnostics
Safe
Rev'led
Safe
Un-rvld
Dangrs
Detect
Dangrs
Un-detec
Safe
Rev'led
Safe
Un-rvld
Dangrs
D tect
Dangrs
Un-det c
Safe No-
effect
0
0.00037
0
0
0
0
3.7E-05 4.1E-06
0
0.00037
0
0
0
0
4.1E-05
0
0
0
0
0
0.00009 0.00001
0
0
0.00036 0.00004
0
0
0.0058
0
0
0.00145
0
0
0
0
0
0
0.00056 6.2E-05
0
0
0.00223 0.00025
0
0
0
0.00026 2.8E-05
0
0
0
0
0 086
0
0
0.00026 2.8E-05
0
0
0
0
0.0086
0
0
0.00026 2.8E-05
0
0
0
0
0.0086
0
0
0
0
0
0
0
0
0.00888
0
0.00028
0
0
0
0
0
0
0.0086