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 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]. When it comes to…
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 MoreISO 13849 – 1 Analysis — Part 6: CCF — Common Cause Failures
Post updated 2019-07-24. Ed. 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…
Read MoreTesting Emergency Stop Systems
I’ve had a number of questions from readers regarding testing of emergency stop systems, and particularly with the frequency of testing. I addressed the types of tests that might be needed in…
Read MoreCSA Z432 Safeguarding of Machinery – 3rd Edition
If you build machinery for the Canadian market, or if you modify equipment in Canadian workplaces, you will be familiar with CSA Z432, Safeguarding of Machinery. This standard has been…
Read MoreEmergency stop devices: the risks of installer liability
On the MachineBuilding.net blog today, Alex D’Arcy, Sales Director at Hylec-APL provides some interesting insights into the liabilities associated with the installation of emergency stop devices on machinery. Hylec-APL provides technical…
Read MoreInterlock Architectures – Pt. 5: Category 4 – Control Reliable
Ed. note: I’ve made a few updates to this article since it was first published in 2011, with the most recent on 2020-05-11. – DN – The most reliable of the…
Read MoreInterlock Architectures – Pt. 4: Category 3 – Control Reliable
This post was updated on 2020-03-28. Category 3 system architecture is the first category that could be considered to have similarity to “Control Reliable” circuits or systems as was defined in…
Read MoreUpdates to Popular Articles
We’ve recently updated a couple of our popular articles! Check them out! Busting Emergency Stop Myths Reader Question: Multiple E‑Stops and Resets