A.4.2.8
Risk reduction
Risk reduction measures for a machine can be implemented by means of safety-related control
functions in addition to structural measures. To implement these control functions, special
requirements must be taken into account, graded according to the magnitude of the risk. These
are described in EN ISO 13849-1 or, in the case of electrical controllers (particularly
programmable electronics), in EN 61508 or EN 62061. The requirements regarding safety-
related controller components are graded according to the magnitude of the risk and the level
to which the risk needs to be reduced.
EN ISO 13849-1 defines a risk flow chart that instead of categories results in hierarchically
graduated Performance Levels (PL).
IEC/EN 62061 uses "Safety Integrity Level" (SIL) for classification purposes. This is a
quantified measure of the safety-related performance of a controller. The required SIL is also
determined in accordance with the risk assessment principle according to ISO 12100 (EN
1050). Annex A of the standard describes a method for determining the required Safety
Integrity Level (SIL).
Regardless of which standard is applied, steps must be taken to ensure that all the machine
controller components required for executing the safety-related functions fulfill these
requirements.
A.4.2.9
Residual risk
In today's technologically advanced world, the concept of safety is relative. The ability to ensure
safety to the extent that risk is ruled out in all circumstances – "zero-risk guarantee" – is
practically impossible. The residual risk is the risk that remains once all the relevant protective
measures have been implemented in accordance with the latest state of the art.
Residual risks must be clearly referred to in the machine/plant documentation (user information
according to EN ISO 12100).
A.4.2.10
EC declaration of conformity
The EC Declaration of Conformity for the product can be obtained from your local Siemens
office or in the Internet at:
EC declaration of conformity (
https://support.industry.siemens.com/cs/ww/en/view/67385845
A.4.3
Machine safety in the USA
A key difference between the USA and Europe in the legal requirements regarding safety at
work is that, in the USA, no legislation exists regarding machinery safety that is applicable in
all of the states and that defines the responsibility of the manufacturer/supplier. A general
requirement exists stating that employers must ensure a safe workplace.
Appendix
A.4 Standards and specifications
Safety Integrated - SINAMICS G110M, G120, G120C, G120D and SIMATIC ET 200pro FC-2
430
Function Manual, 01/2017, FW V4.7 SP6, A5E34261271B AD