Machinery Safety 101

Get the Basics Right!

For more than 15 years I’ve been teach­ing people about risk assess­ment, machinery safety and CE Mark­ing of machinery in private, onsite classes and through present­a­tions at safety con­fer­ences. Things are about to change! This fall, Com­pli­ance InSight Con­sult­ing will begin offer­ing open-enrol­­ment work­shops in CE Mark­ing, Risk Assess­ment Func­tion­al Safety, and Machinery Safety, all with a focus…

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How to migrate from EN 954 – 1 to EN ISO 13849 – 1 or EN 62061

Edit­or­’s note – When I read this art­icle on the machinebuilding.net blog, I thought that it was import­ant enough that we should reprint it here. The text includes links to the machinebuilding.net web site. These resources can def­in­itely help you in apply­ing this inform­a­tion. If you have ques­tions that you would like to dis­cuss, please con­tact me and…

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Interlocking Devices: The Good, The Bad and the Ugly

This entry is part 1 of 7 in the series Guards and Guard­ing

Note: A short­er ver­sion of this art­icle was pub­lished in the May-2012 edi­tion of  Man­u­fac­tur­ing Auto­ma­tion Magazine. When design­ing safe­guard­ing sys­tems for machines, one of the basic build­ing blocks is the mov­able guard. Mov­able guards can be doors, pan­els, gates or oth­er phys­ic­al bar­ri­ers that can be opened without using tools. Every one of these guards…

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31-Dec-2011 – Are YOU ready?

This entry is part 8 of 8 in the series Cir­cuit Archi­tec­tures Explored

31-Decem­ber-2011 marks a key mile­stone for machine build­ers mar­ket­ing their products in the European Uni­on, the EEA and many of the Can­did­ate States. Func­tion­al Safety takes a pos­it­ive step for­ward with the man­dat­ory applic­a­tion of EN ISO 13849 – 1 and ‑2. As of 1‑Janu­ary-2012, the safety-related parts of the con­trol sys­tems on all machinery bear­ing a CE Mark will be…

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Inconsistencies in ISO 13849 – 1:2006

This entry is part 7 of 8 in the series Cir­cuit Archi­tec­tures Explored

I’ve writ­ten quite a bit recently on the top­ic of cir­cuit archi­tec­tures under ISO 13849 – 1, and one of my read­ers noticed an incon­sist­ency between the text of the stand­ard and Fig­ure 5, the dia­gram that shows how the cat­egor­ies can span one or more Per­form­ance Levels. If you look at Cat­egory 2 in Fig­ure 5, you will notice…

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Interlock Architectures Pt. 6 – Comparing North American and International Systems

industrial Control Console
This entry is part 6 of 8 in the series Cir­cuit Archi­tec­tures Explored

I’ve now writ­ten six posts, includ­ing this one, on the top­ic of cir­cuit archi­tec­tures for the safety-related parts of con­trol sys­tems. In this post, we’ll com­pare the Inter­na­tion­al and North Amer­ic­an sys­tems. This com­par­is­on is not inten­ded to draw con­clu­sions about which is “bet­ter”, but rather to com­pare and con­trast the two sys­tems so that…

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Interlock Architectures – Pt. 5: Category 4 — Control Reliable

This entry is part 5 of 8 in the series Cir­cuit Archi­tec­tures Explored

Ed. note: I’ve made a few updates to this art­icle since it was first pub­lished in 2011, with the most recent today, 6‑Dec-18. – DN – The most reli­able of the five sys­tem archi­tec­tures, Cat­egory 4 is the only archi­tec­ture that uses mul­­tiple-fault tol­er­ant tech­niques to help ensure that com­pon­ent fail­ures do not res­ult in an unac­cept­able…

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Interlock Architectures – Pt. 4: Category 3 – Control Reliable

Category 3 Architecture Logic Block Diagram
This entry is part 4 of 8 in the series Cir­cuit Archi­tec­tures Explored

Cat­egory 3 sys­tem archi­tec­ture is the first cat­egory that could be con­sidered to have sim­il­ar­ity to “Con­trol Reli­able” cir­cuits or sys­tems as defined in the North Amer­ic­an stand­ards. It is not the same as Con­trol Reli­able, but we’ll get to in a sub­sequent post. If you haven’t read the first three posts in this series, you may…

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Understanding the Hierarchy of Controls

The Hierarchy of Controls illustrated as an inverted triangle with each level of the hierarchy written one above the other, starting with Inherently Sfe design, then Engineering Controls, then Information for Use, then Administrative Controls and finally descending to PPE at the bottom. An arrow with the text "Effectiveness" on it runs parallel to the triangle and points downward from Inherently safe design to PPE.
This entry is part 4 of 5 in the series Hier­archy of Con­trols

(Eds. note: This art­icle was ori­gin­ally writ­ten in 2011 and was updated in Nov. 2018.) The “Hier­archy of Con­trols” is one approach to risk reduc­tion that has become entrenched in the Occu­pa­tion­al Health and Safety (OHS) sec­tor. There are oth­er approaches to risk reduc­tion which are equally effect­ive but are less rigidly struc­tured. If you…

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Missing MTTFd data

Deal­ing with the huge inform­a­tion void that exists while try­ing to com­plete reas­on­able con­trol reli­ab­il­ity assess­ments is a major chal­lenge for every engin­eer or tech­no­lo­gist tasked with this activ­ity. Here are a few thoughts on what to do now, and where things may be going…

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