Updated 2020-10-31. DN 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…
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 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 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 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 MoreMore E‑Stop Questions
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…
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