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Why is functional safety required?

So that risks associated with machinery can be reduced by means of safety functions. Functional safety refers to the safeguarding of a machine control system that is responsible for ensuring the correct operation of personal protection.

Requirements for machine safety

Machinery in accordance with the Machinery Directive  

Machinery in accordance with the Machinery Directive

In order to achieve functional safety, defined measures must be taken. The risk assessment typically enables you to determine the various types and number of safety functions. The requirements for machine safety are described with the 3-stage method in Annex 1 of the Machinery Directive. According to this, the following general principles must be applied:

  • Design-related measures. The intended use and every reasonably foreseeable incorrect use is taken into consideration.
  • Technical safeguarding against risks that cannot be reduced by design. These include measures for functional safety.
  • Indicative measures. User notes, operating instructions, special instruction and training, personal protective equipment.

These requirements of the Machinery Directive are binding for all machine manufacturers.

Aim of functional safety

Functional safety prevents errors that may lead to hazardous situations on machinery. A distinction is made between various types of error:

  • Systematic errors: human error in the specification, design, and implementation of safety functions.
  • Random errors: hardware faults.
  • Errors with a common cause: triggered by an event, such as a surge voltage, which causes several units to fail.

These types of error can be reduced by taking appropriate organizational and/or technical measures. All requirements prescribed by standards for the functional safety of systems should be observed. The safety lifecycle for machines provides the basis for the possible procedures. Phoenix Contact again offers services that focus on these aspects.


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Auckland 1061
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