The phone rings on my desk. It’s an engineer from a manufacturing company in Colorado calling to ask for advice. He wants to know if a contactor should be applied to an output circuit to achieve a safe circuit? What’s wrong here? Yea, the first question is where’s the risk assessment? What level of hazard are we dealing with? Is ...

Check this out! Do you wire your e-stops to a standard (non Safety) PLC or controller in order to comply with the mandatory category 0 or 1 stop? Think twice is my advice! Yes, the safety standards such as NFPA 79, 9.2.5.4.1.3 require that an e-stop "shall function as either Category 0 or a Category 1 stop". These are stopping ...

Great News!   My machine safety blog is now part of an innovative new educational-based safety website that’s sole purpose is to serve the safety needs of general industry.  I’m excited to be a part of a group of industry experts who’ve come together to provide up-to-date, comprehensive information, ideas, forums, ...

How many hands can I see for “safety device”? Now, how many of you say – no, an e-stopping device is not a safety device? I see! So the room is practically divided into two camps. One of the camps has several individuals that sit on safety standards committees and others who are suppliers of e-stopping devices. You guys have ...

Tolerable risk is the term used for the past several years referring to a level of residual risk for a given hazard after applying risk reduction measures. ANSI B11.TR3; 2000 further defines tolerable risk as: Risk that is accepted for a given task and hazard combination [hazardous situation]. However, as more focus continues to be directed at ...

I often hear discussions about NFPA 79 (Electrical Standard for Industrial Machinery) having more importance than the ANSI B11 series of machine tool standards. Conversely, there’s an equal if not larger camp of user’s that profess the ANSI B11 series as “the rule of the land” inferring that NFPA 79 takes a back seat to ...

We’ll – from where I stand it’s been since 1999 that the voluntary consensus standards began their migration march of updating approaches for machine safe guarding. That first standard was RIA 15.06 for industrial robots. One of many changes of this updated standard was the requirement to conduct a risk analysis on all robots ...

Some folks in machine safety are off learning about European standards like IEC 60204, IEC 62061, and the recently updated ISO 13849-1. These standards talk about the safe guarding of machines and use terms like; SIL (Safety Integrity Level), PL (Performance Level), MTTFD  (Mean Time To Fail dangerous), SIL Claim Limit to mention a few! All ...

How can this be? How could machine safety be more simple and easy than hard wiring 50 or 100 relays back to a machine control system? We’ve been doing it this way for over 30 years and our machine up time is above average at 68%!  How many of us have heard this story? We’ll, the safety landscape has changed! Industry has new ...

Some folks in machine safety are off learning about European standards like IEC 60204, IEC 62061, and the October 2006 updated ISO 13849-1. These standards talk about the safe guarding of machines and use terms like; SIL (Safety Integrity Level), PL (Performance Level), MTTFD  (Mean Time To Fail dangerous), and SIL Claim Limit to mention a ...