A.4.2.6 Series of standards IEC 61508 (VDE 0803)
This series of standards describes the current state of the art.
IEC 61508 is not harmonized in line with any EU directives, which means that an automatic
presumption of conformity for fulfilling the protective requirements of a directive is not implied.
The manufacturer of a safety-related product, however, can also use IEC 61508 to fulfill basic
requirements of European directives in accordance with the latest conceptual design, for
example, in the following cases:
● If no harmonized standard exists for the application in question. In this particular case, the
manufacturer may use IEC 61508. although no presumption of conformity exists here.
● A harmonized European standard (e.g. EN 62061, EN ISO 13849, EN 60204-1) references
IEC 61508. This ensures that the appropriate requirements of the directives are fulfilled
("standard that is also applicable"). When manufacturers apply IEC 61508 properly and
responsibly in accordance with this reference, they can use the presumption of conformity
of the referencing standard.
IEC 61508 covers all the aspects that must be taken into account when E/E/PES systems
(electrical, electronic, and programmable electronic system) are used in order to execute 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.
A.4.2.7 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.
Appendix
A.4 Standards and specifications
Safety Integrated - SINAMICS G110M, G120, G120C, G120D and SIMATIC ET 200pro FC-2
428 Function Manual, 01/2017, FW V4.7 SP6, A5E34261271B AD
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