Risk Analysis/Assessment - Siemens SINAMICS V90 Operating Instructions Manual

EN 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 EN 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.
8.1.2.7

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 12100-1 "Safety of Machinery - basic terminology, general principles for design"
EN ISO 13849-1 (successor to EN 954-1) "Safety-related parts of control systems"
EN ISO 12100-1 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 12100-1)
– Identification of the hazards (EN ISO 12100-114)
– 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.
SINAMICS V90, SIMOTICS S-1FL6
Operating Instructions, 07/2015, 6SL3298-0AV60-0BP0
Safety Integrated function
8.1 Standards and regulations
209