This post was updated 2019-07-24 I often get questions from clients about how to get started on Functional Safety using ISO 13849. This article is the first in a series that will walk you through the basics of using ISO 13849. Keep in mind that you will need to hold a copy of the 3rd edition of ISO 13849 – 1 [1]…
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 another article covering Checking Emergency Stop Systems. This article will focus on the frequency of testing rather than the types of tests. The Problem Emergency…
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 around since 1992, with the last major revision published in 2004. CSA has reconvened the Technical Committee responsible for this important standard to revise the…
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 products and solutions in the field of industrial machinery and emergency stop systems. Check out Alex’s article. If you need to know more about the…
Interlock 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 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…
Read MoreInterlock Architectures – Pt. 4: Category 3 – Control Reliable
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…
Read MoreNew contact block design for Emergency Stop devices from Siemens
One issue that frequently comes up when inspecting machinery is the contact blocks used on emergency stop devices. Until now, e‑stop devices were normally fitted with the same contact blocks used on other operator devices, and in cases where the e‑stop system is single channel, you could lose the contact block off the back of…
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
Reader Question: Multiple E‑Stops and Resets
I had an interesting question come in from a reader today that is relevant to many situations: “When you have multiple E‑Stop buttons I have often gotten into an argument that says you can have a reset beside each one. I was taught that you were required to have a single point of reset. Who is correct?” — Michael Barb,…
Read MoreUnderstanding the 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…
Read More