Canada

Instructions for Use – the New ISO 20607

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Instruc­tions are one of the basic items that users expect to get when they pur­chase a product, and yet these import­ant doc­u­ments are often poorly writ­ten, badly trans­lated, and incom­plete. Key product fea­tures are badly described, and inform­a­tion on fea­tures, set­tings and haz­ards may be absent. All of this des­pite the fact that the min­im­um require­ments […]

CE Mark

Brexit is such a waste

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Brexit: UK and EU Flags against a blue sky

This morn­ing I read news of the tests that the May Gov­ern­ment plans to use when assess­ing the Brexit deal they are try­ing to nego­ti­ate with the EU. The @CommonsEUexit report on the UK/EU future rela­tion­ship has just been pub­lished. Here are its “key tests” for judging a future deal. Full text of the report here – […]

Canada

Machinery Safety Labels: 3 Top Tools for Effective Warnings

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Safety label by Clarion Safety Systems
This entry is part 1 of 3 in the series Safety Labels

Machinery Safety Labels The third level of the Hier­archy of Con­trols is Inform­a­tion for Use. Safety Labels are a key part of the Inform­a­tion for Use provided by machine build­ers to users and are often the only inform­a­tion that many users get to see. This makes the design and place­ment of the safety labels crit­ic­al to […]

Canada

Safe Drive Control including Safe Torque Off (STO)

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Graph illustrating STO Function
This entry is part 12 of 16 in the series Emer­gency Stop

Ed. Note: This art­icle was revised 25-Jul-17 to include inform­a­tion on safe stand­still. Safe Drive Con­trol includ­ing STO Motor drives are every­where. From DC vari­able speed drives and index­ing drives, through AC Vari­able Fre­quency drives, servo drives and step­per motor drives, the cap­ab­il­it­ies and the flex­ib­il­ity of these elec­tron­ic sys­tems has giv­en machine design­ers unpre­ced­en­ted […]

Canada

ISO 13849 – 1 Analysis — Part 8: Fault Exclusion

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This entry is part 9 of 9 in the series How to do a 13849 – 1 ana­lys­is

Fault Con­sid­er­a­tion & Fault Exclu­sion ISO 13849 – 1, Chapter 7 [1, 7] dis­cusses the need for fault con­sid­er­a­tion and fault exclu­sion. Fault con­sid­er­a­tion is the pro­cess of examin­ing the com­pon­ents and sub-sys­tems used in the safety-related part of the con­trol sys­tem (SRP/CS) and mak­ing a list of all the faults that could occur in each one. This a def­in­itely non-trivi­al […]

CE Mark

An update on CE Marking Electrical Cable

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CE Mark­ing Wire and Cable In an earli­er post, I wrote about the require­ments for CE Mark­ing wire and cable and dis­cussed the <HAR> mark. In 2016, the Con­struc­tion Products Reg­u­la­tion 305/2011 (CPR) came into effect, repla­cing the Con­struc­tion Products Dir­ect­ive 89/106/EEC. The CPR included pro­vi­sions cov­er­ing any kind of mater­i­als that could be used in […]

Canada

ISO 13849 – 1 Analysis — Part 6: CCF — Common Cause Failures

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This entry is part 6 of 9 in the series How to do a 13849 – 1 ana­lys­is

What is a Com­mon Cause Fail­ure? There are two sim­il­ar-sound­ing terms that people often get con­fused: Com­mon Cause Fail­ure (CCF) and Com­mon Mode Fail­ure. While these two types of fail­ures sound sim­il­ar, they are dif­fer­ent. A Com­mon Cause Fail­ure is a fail­ure in a sys­tem where two or more por­tions of the sys­tem fail at the same time from a single […]

Canada

ISO 13849 – 1 Analysis — Part 5: Diagnostic Coverage (DC)

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A graph showing the theoretical "bathtub curve" for product failure rate over the lifetime of the product.
This entry is part 5 of 9 in the series How to do a 13849 – 1 ana­lys­is

What is Dia­gnost­ic Cov­er­age? Under­stand­ing Dia­gnost­ic Cov­er­age (DC) as it is used in ISO 13849 – 1 [1] is crit­ic­al to ana­lys­ing the design of any safety func­tion assessed using this stand­ard. In case you missed a pre­vi­ous part of the series, you can read it here. In the last instal­ment of this series dis­cuss­ing MTTFD, I brought up the […]

Canada

ISO 13849 – 1 Analysis — Part 4: MTTFD – Mean Time to Dangerous Failure

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This entry is part 4 of 9 in the series How to do a 13849 – 1 ana­lys­is

Func­tion­al safety is all about the like­li­hood of a safety sys­tem fail­ing to oper­ate when you need it. Under­stand­ing Mean Time to Dan­ger­ous Fail­ure, or MTTFD, is crit­ic­al. If you have been read­ing about this top­ic at all, you may notice that I am abbre­vi­at­ing Mean Time to Dan­ger­ous Fail­ure with all cap­it­al let­ters. Using MTTFD is […]

Canada

ISO 13849 – 1 Analysis — Part 3: Architectural Category Selection

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This entry is part 3 of 9 in the series How to do a 13849 – 1 ana­lys­is

At this point, you have com­pleted the risk assess­ment, assigned required Per­form­ance Levels to each safety func­tion, and developed the Safety Require­ment Spe­cific­a­tion for each safety func­tion. Next, you need to con­sider three aspects of the sys­tem design: Archi­tec­tur­al Cat­egory, Chan­nel Mean Time to Dan­ger­ous Fail­ure (MTTFD), and Dia­gnost­ic Cov­er­age (DCavg). In this part of the […]