Here are some more questions I’ve been asked regarding emergency stop requirements. These ones came to me through the IEEE PSES EMC-PSTC Product Compliance Forum mailing list. Primary Sources There…
Read MoreCan Emergency Stop be used as an “on/off” control?
Every couple of months I get an email asking me if there is any reason why e‑stop functions can’t be used as the primary power control (on/off button) for machinery. Following…
Read MoreIntroduction to Functional Safety Seminars
If you are interested in functional safety, and I know many readers are based on the statistics I see for my other functional safety-related posts, I think you will be interested in this.…
Read MoreEmergency Stop Pull-Cords
This article was updated 2020-06-13, adding links to the Rockwell Automation and Schmersal pull-cord data, and on 2019-04-26, adding specific details related to IEC 60947 – 5‑5 [7]. Additional vendor links and…
Read MoreEmergency Stop Failures
I am always looking for interesting examples of machinery safety problems to share on MS101. Recently I was scrolling Reddit/r/OSHA and found these three real-world examples. Broken Emergency Stop Buttons The…
Read MoreSafe Drive Control including Safe Torque Off (STO)
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,…
Read MoreHow to do a 13849 – 1 analysis: Complete Reference List
Post updated 2019-07-24. Ed. As promised in previous posts, here is the complete reference list for the series “How to do a 13849 – 1 analysis”! If you have any additional resources you…
Read MoreISO 13849 – 1 Analysis — Part 8: Fault Exclusion
Post updated 2019-07-24. Ed. 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…
Read MoreISO 13849 – 1 Analysis — Part 3: Architectural Category Selection
Post updated 2019-07-24. Ed. 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…
Read MoreISO 13849 – 1 Analysis — Part 2: Safety Requirement Specification
This article was updated 2019-07-24. Ed. Developing the Safety Requirement Specification The Safety Requirement Specification sounds pretty heavy, but actually, it is just a big name for a way to organize the…
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