Risk Analysis/Assessment - Siemens Sinamics S120 Function Manual

Standards and regulations
10.2 Safety of machinery in Europe
safety functions and/or to ensure the appropriate level of functional safety. Other hazards
(e.g. electric shock) are not part of the standard, similar to DIN ISO 13849.
IEC 61508 has recently been declared the "International Basic Safety Publication", which
makes it a framework for other sector-specific standards (e.g. EN 62061). As a result, this
standard is now accepted worldwide, particularly in North America and in the automotive
industry. Today, many regulatory bodies already stipulate it (e.g. as a basis for NRTL listing).
Another recent development with respect to IEC 61508 is its system approach, which
extends the technical requirements to include the entire safety installation from the sensor to
the actuator, the quantification of the probability of hazardous failure due to random
hardware failures, and the creation of documentation covering all phases of the safety-
related lifecycle of the E/E/PES.
10.2.7

Risk analysis/assessment

Risks are intrinsic in machines due to their design and functionality. For this reason, the
Machinery Directive requires that a risk assessment be performed for each machine and, if
necessary, the level of risk reduced until the residual risk is less than the tolerable risk. To
assess these risks, the following standards must be applied:
● EN ISO 12100 "Safety of Machinery - General Design Principles - Risk Assessment and
Minimizing Risks"
● EN ISO 13849-1 (successor to EN 954-1) "Safety-related parts of control systems"
EN ISO 12100 focuses on the risks to be analyzed and the design principles for minimizing
risk.
The risk assessment is a procedure that allows hazards resulting from machines to be
systematically investigated. Where necessary, the risk assessment is followed by a risk
reduction procedure. When the procedure is repeated, this is known as an iterative process.
This can help eliminate hazards (as far as this is possible) and can act as a basis for
implementing suitable protective measures.
The risk assessment involves the following:
● Risk analysis
– Determines the limits of the machine (EN ISO 12100)
– Identification of hazards (EN ISO 12100)
– Estimating the level of risk (EN 1050 Paragraph 7)
● Risk evaluation
As part of the iterative process to achieve the required level of safety, a risk assessment is
carried out after the risk estimation. A decision must be made here as to whether the
residual risk needs to be reduced. If the risk is to be further reduced, suitable protective
measures must be selected and applied. The risk assessment must then be repeated.
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Function Manual, (FHS), 07/2016, 6SL3097-4AR00-0BP6
Safety Integrated