KROHNE OPTISWITCH-3x00C User Manual
Safety Manual
OPTISWITCH series 3000
- contactless electronic switch
Content
Content
1 Functional safety
1.1 General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.2 Planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.3 Adjustment instructions . . . . . . . . . . . . . . . . . .
1.4 Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.5 Reaction during operation and in case of failure.
1.6 Recurring function test . . . . . . . . . . . . . . . . . . .
1.7 Safety-related characteristics . . . . . . . . . . . . . .
3
4
7
7
7
8
8
2 OPTISWITCH series 3000 • - contactless electronic switch
32741-EN-080414
1 Functional safety
1.1 General
Functional safety
Scope
Area of application
SIL conformity
Abbreviations, terms
This safety manual applies to measuring systems consisting of
the vibrating level switch OPTISWITCH series 3000 with
integrated oscillator VB60C:
OPTISWITCH 3100 C, 3200 C, 3300 C
Valid hardware and software versions:
l Serial number of the electronics >14215928
l Sensor software from Rev. 1.03
The measuring system can be implemented for level detection
of bulk solids (powders and granulates) which meets the
special requirements of safety technology.
This is possible up to SIL2 in a single channel architecture
(1oo1D), and up to SIL3 in a multiple channel, redundant
architecture.
Note:
With a special factory setting, the measuring system is also
suitable for detection of solids in water (see "Operating
instructions manual").
The SIL declaration of conformity can be downloaded from our
homepage in the Internet.
Further abbreviations and terms are stated in IEC 61508-4.
SIL Safety Integrity Level
HFT Hardware Fault Tolerance
SFF Safe Failure Fraction
PFD
PFH Probability of a dangerous Failure per Hour
FMEDA Failure Mode, Effects and Diagnostics Analysis
λ
sd
λ
su
λ
dd
λ
du
DC
S
DC
D
Average Probability of dangerous Failure on Demand
avg
Rate for safe detected failure
Rate for safe undetected failure
Rate for dangerous detected failure
Rate for dangerous undetected failure
Diagnostic Coverage of safe failures; DCS= λsd/(λsd+λsu)
Diagnostic Coverage of dangerous failures; DCD= λdd/(λdd+λdu)
32741-EN-080414
OPTISWITCH series 3000 • - contactless electronic switch 3
Functional safety
FIT Failure In Time (1 FIT = 1 failure/109h)
MTBF Mean Time Between Failure
MTTF Mean Time To Failure
MTTR Mean Time To Repair
Relevant standards
Safety requirements
l IEC 61508 (also available as DIN EN)
- Functional safety of electrical/electronic/programmable
electronic safety-related systems
Failure limit values for a safety function, depending on the SIL
class (of IEC 61508-1, 7.6.2)
Safety integrity level Low demand mode High demand mode
SIL PFD
4 ≥ 10
3 ≥ 10-4… < 10
2 ≥ 10-3… < 10
1 ≥ 10-2… < 10
-5
… < 10
avg
-4
-3
-2
-1
Safety integrity of hardware for safety-related subsystems of
type B (IEC 61508-2, 7.4.3)
Safe failure fraction Hardware
SFF HFT = 0 HFT = 1 HFT = 2
< 60 % not permitted SIL1 SIL2
60 % … < 90 % SIL1 SIL2 SIL3
90 % … < 99 % SIL2 SIL3 (SIL4)
≥ 99 % SIL3 (SIL4) (SIL4)
fault tolerance
PFH
≥ 10-9… < 10
≥ 10-8… < 10
≥ 10-7… < 10
≥ 10-6… < 10
-8
-7
-6
-5
1.2 Planning
Safety function
4 OPTISWITCH series 3000 • - contactless electronic switch
The safety function of this measuring system is the identi-
fication and signalling of the condition of the vibrating element.
A difference is made between the two conditions "covered"
and "uncovered".
32741-EN-080414
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