The introduction of the new Machinery Directive 2006/42/EG brings with it fundamental changes to risk assessment and risk reduction. As a competent partner for the machine-building industry Weidmüller supports its customers to help them comply with the new requirements.
Part 1 Closer look at MTTF values of relays and opto modules
In order to be able to make binding statements with regard to the failure probability of systems and individual signal lines engineers require so-called MTTF values. The statistical key indicator MTTF stands for “Mean Time To Failure”, which denotes the average operating time until a failure or malfunction occurs.
For the machine and systems builder adhering to the new standard begins with reducing risks in control and drive technology applications, as these are the source of the greatest risks. By disclosing and making available all values necessary to perform a conformity assessment Weidmüller supports users in the fields of application in which its relays and opto modules are utilised.
Part 2 High MTBF times with high quality power supplies
One essential criterion required in order to be able to make a binding statement on the failure probability of a system is information on the reliability of the installed power supply units.
By utilising high quality power supply units with high MTBF values on the one hand and by additionally creating a redundant power supply on the other mechanical and systems engineers are able to significantly reduce risks to their applications and, as a result, they are also complying with the new Machinery Directive.
Part 3 Surge protection to avoid failures resulting from a common cause
One requirement resulting from the new Machinery Directive is the avoidance of common cause failures (CCFs) in regards to machine safety as described by the EN ISO 13849-1 standard.
One suitable step for the avoidance of common cause failures is providing reliable surge voltage protection. When machine and facility engineers are able to determine that they can prevent a direct or indirect lightning strike from causing destruction, they are entitled to 15 of the 100 evaluation points in the Machinery Directive assessment scale. This already gives them almost a quarter of the 65 points need to fulfill the CCF requirement.
Published in November 2013
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