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BETA Monitoring
Monitoring of Plants and Devices
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TT5 2 EMERGENCY-STOP modules
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Siemens ET B1 · 10/2008
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Risk analysis and selection of a suitable category
Engineers and operators assume responsibility for the correct
risk assessment.
It is difficult to make a quantitative assessment of the risk, so that
when selecting the category, the reasonable risk can be
determined within a broad band width.
This becomes clear if you select "F2 – frequently to continuous"
instead of "F1 – rarely to frequently", for the risk parameters
"
F – Frequency and duration" when drawing up a risk graph
(
see image).
The whole band width of safety categories may lie between the
assessment of "often" and "frequently".
Key standards
•
EN 60204-1 (VDE 0113-1):1998
"
Safety of machinery – Electrical equipment of machinery
Part 1: General requirements"
•
EC Machine Directive 98/37/EC
•
EN 292-1:1991
"
Basic concepts, general principles for design
Part 1: Basic terminology, methodology "
•
EN 292-2:1991 and EN 292-2/A1:1995
"
Basic concepts, general principles for design
Part 2: Technical principles and specifications "
•
EN 418:1992
"
Safety of machinery – EMERGENCY-STOP equipment,
functional aspects, principles for design"
•
EN 954-1:1996
"
Safety of machinery – Safety-related parts of control systems
Part 1: General principles for design"
•
EN 1088:1995
"
Safety of machinery – Interlocking devices associated with
guards – Principles for design and selection".
I2_08404b
B 1 2 3 4
minor injury
serious and irreversible
injury of one or several
personsor death of a
person
rarely to frequently
frequently to constantly
possible under certain
circumstances
possible under certain
circumstances
hardly possible
preferred categories for
reference points
possible category which requires
additional measures with regard
to the risk
overdimensioned measures with
regard to the risk
Categories
hardly possible
seriousness of injury
Risk parameter F:
Risk parameter P:
frequency and
duration
possibility of
avoiding injuries
Risk parameter S:
© Siemens AG 2008