Machinery Safety 101

Understanding Safety Functions: the Safety-related stop function

A stop sign - A red octagon with a white border, and white block text reading STOP.
This entry is part of 3 in the series Under­stand­ing Safety Functions

The most used safety func­tion on machinery is the safety-related stop func­tion. The require­ments dis­cussed in this post are not gen­er­ally applic­able to pro­­cess-related stop func­tions unless the pro­cess and… 

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Manual reset using an HMI

A Siemens HMI displaying control functions and data.
This entry is part 2 of 3 in the series Under­stand­ing Safety Functions

Ques­tion: Can a safety-related stop func­tion, for example, be reset via a graph­ic­al object rep­res­ent­ing a reset but­ton on an HMI? The short answer: No, with an excep­tion. Read on if you’d like… 

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What is risk assessment?

This entry is part 11 of 10 in the series Risk Assess­ment

Risk assess­ment began as a dis­cip­line in the late 1960s, with some of the earli­est form­al papers pub­lished in the early 1970s. The early research­ers were part of the US military… 

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What exactly is PELV?

Photo of the interior of an electrical control cabinet showing the components and wireways on the backplane.

What exactly is PELV? Elec­tric­al design­ers run into all kinds of spe­cial­ized ter­min­o­logy as part of their work. IEC is notori­ous for cre­at­ing spe­cial­ized terms that are not famil­i­ar to… 

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Force and injury — How hard is too hard? ISO/TR 21260 will help

ISO/TS 15066 body model
This entry is part 5 of 5 in the series Hier­archy of Controls

Force rep­res­ents the mech­an­ic­al energy that causes injury to the human body. ISO/TC 199 has been work­ing on answer­ing that ques­tion since 2012.

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