Safety Integrated; Standards And Regulations; General Information; Aims - Siemens SINUMERIK 808D Function Manual

22

Safety Integrated

22.1

Standards and regulations

22.1.1

General information

22.1.1.1

Aims

Manufacturers and operating companies of equipment, machines, and products are responsible for ensuring the required
level of safety. This means that plants, machines, and other equipment must be designed to be as safe as possible in
accordance with the current state of the art. To ensure this, companies describe in the various standards the current state of
the art covering all aspects relevant to safety. When the relevant Standards are observed, this ensures that state-of-the-art
technology has been utilized and, in turn, the erector/builder of a plant or a manufacturer of a machine or a piece of
equipment has fulfilled his appropriate responsibility.
Safety systems are designed to minimize potential hazards for both people and the environment by means of suitable
technical equipment, without restricting industrial production and the use of machines more than is necessary. The
protection of man and environment must be assigned equal importance in all countries, which is it is important that rules and
regulations that have been internationally harmonized are applied. This is also designed to avoid distortions in the
competition due to different safety requirements in different countries.
There are different concepts and requirements in the various regions and countries of the world when it comes to ensuring
the appropriate degree of safety. The legislation and the requirements of how and when proof is to be given and whether
there is an adequate level of safety are just as different as the assignment of responsibilities.
The most important thing for manufacturers of machines and companies that set up plants and systems is that the legislation
and regulations in the country where the machine or plant is being operated apply. For example, the control system for a
machine that is to be used in the US must fulfill local US requirements even if the machine manufacturer (OEM) is based in
the European Economic Area (EEA).
22.1.1.2

Functional safety

Safety, from the perspective of the object to be protected, cannot be split-up. The causes of hazards and, in turn, the
technical measures to avoid them can vary significantly. This is why a differentiation is made between different types of
safety (e.g. by specifying the cause of possible hazards). "Functional safety" is involved if safety depends on the correct
function.
To ensure the functional safety of a machine or plant, the safety-related parts of the protection and control devices must
function correctly. In addition, the systems must behave in such a way that either the plant remains in a safe state or it is
brought into a safe state if a fault occurs. In this case, it is necessary to use specially qualified technology that fulfills the
requirements described in the associated Standards. The requirements to achieve functional safety are based on the
following basic goals:
● Avoiding systematic faults
● Controlling systematic faults
● Controlling random faults or failures
Benchmarks for establishing whether or not a sufficient level of functional safety has been achieved include the probability of
hazardous failures, the fault tolerance, and the quality that is to be ensured by minimizing systematic faults. This is
expressed in the Standards using different terms. In IEC/EN 61508, IEC/EN 62061 "Safety Integrity Level" (SIL) and EN ISO
13849-1 "Categories" and "Performance Level" (PL).
22.1.2

Safety of machinery in Europe

The EU Directives that apply to the implementation of products are based on Article 95 of the EU contract, which regulates
the free exchange of goods. These are based on a new global concept ("new approach", "global approach"):
● EU Directives only specify general safety goals and define basic safety requirements.
● Technical details can be defined by means of standards by Standards Associations that have the appropriate mandate
from the commission of the European Parliament and Council (CEN, CENELEC). These standards are harmonized in
line with a specific directive and listed in the official journal of the commission of the European Parliament and Council.
Legislation does not specify that certain standards have to be observed. When the harmonized Standards are observed,
it can be assumed that the safety requirements and specifications of the Directives involved have been fulfilled.
● EU Directives specify that the Member States must mutually recognize domestic regulations.
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