Machine Safety – does new technology create new hazards?

When NFPA 79 changed by removing requirements for hard wiring machine safety devices in 2002, many automation suppliers introduced new safety rated devices for machine guarding. Domestic standards also have updated requirements to provide direction for use of safety rated devices. Do the new devices represent new hazards, such as lighted emergency stop buttons?

11/07/2012


Jokab Safety giant E-Stop at Pack Expo 2010Since 2002, when NFPA 79 changed by removing requirements for hard wiring machine safety devices, we’ve seen automation suppliers introducing lots of new safety rated devices for machine guarding. Also since 2002, additional domestic standards have likewise updated their requirements to provide direction for use of safety rated devices. Don’t some of these new products introduce possibilities for new hazards? Take for example – lighted emergency stop buttons?

                                                                                                            

Just think for a moment about how a red mushroom button on a safety rated emergency button might work if the red palm button lights up when it’s been activated? Wow, if that’s how it works, the lighted red palm button would surely differentiate it from other red buttons on any operator panel. Right? Has anybody already used any of these devices? Is this how they all work? Or, do lighted emergency stop buttons all work the same way? Aren’t they all regulated by industry standards?

 

Let’s see? For the design and testing of emergency stop devices we have IEC 60947-5-5:2005, Control circuit devices and switching elements – Electrical emergency stop device with mechanical latching function. This standard provides detailed specifications relating to the electrical and mechanical construction of emergency stop devices with mechanical latching function and their testing. For applications of emergency stop devices we have NFPA 79 – 2012, Electrical Standard for Industrial Machinery, ANSI B11.19 – 2010, Performance Criteria for Safeguarding, ISO 13850:2006, Safety of machinery -- Emergency stop -- Principles for design, and IEC 60204-1:2005, Safety of machinery – Electrical equipment of machines. All four of these standards regulate the applications of emergency stop devices in machine control systems. Only IEC 60947-5-5 regulates the design, build and test of an emergency stopping device, however, I don’t believe it addresses the design/application of a lighted button.   

So, if we have a lighted button in a safety rated e-stop device is the light function part of the safety rating? Why is this important? Well, if the device is applied in a Cat 3 or 4 (EN 954) safety circuit does the light need to be redundant in the event the first bulb burns out? Is it a safety critical hazard if the bulb doesn’t even work? Or, is the bulb’s only purpose to aid in reducing the trouble shooting time for resetting the device? Do all lighted e-stop devices from all suppliers function the same way regarding the light function? Can anybody help us out here? 

Do lighted button e-stop devices create a new hazard? 

Your comments or suggestion are always welcome so please let us know your thoughts. Submit your ideas, experiences, and challenges on this subject in the comments section below. Click on the following text if you don't see a comments box, then click into and scroll down in: Machine Safety: Does new technology create new hazards? 

J.B. Titus, CFSERelated articles:

ANSI B11.19-2010, Performance Criteria for Safeguarding

NFPA 79 – 2012, Electrical Standard for Industrial Machinery

E-Stops and Your Compliance

E-Stops Aren’t Safety Devices 

Contact: www.jbtitus.com for “Solutions for Machine Safety”.



Engineers' Choice Awards
The Engineers' Choice Awards highlight some of the best new control, instrumentation and automation products as chosen by Control Engineering subscribers.
System Integrator Giants
The System Integrator Giants program lists the top 100 system integrators among companies listed in CFE Media's Global System Integrator Database.
System Integrator of the Year
Each year, a panel of Control Engineering and Plant Engineering editors and industry expert judges select the System Integrator of the Year Award winners in three categories.
Design of Safe and Reliable Hydraulic Systems for Subsea Applications
This eGuide explains how the operation of hydraulic systems for subsea applications requires the user to consider additional aspects because of the unique conditions that apply to the setting
How to Maximize Factory Automation Efficiency with Low Cost Machine Vision
This eGuide illustrates solutions, applications and benefits of machine vision systems.
Wireless Reliability in Harsh Environments
Learn how to increase device reliability in harsh environments and decrease unplanned system downtime.
September 2018
Optimize controls via cloud software, ladder logic simulation, industrial wireless best practices
August 2018
Augmented reality and virtual reality education, autotuning PID control, cybersecurity advice, educating engineers
July 2018
Ladder logic best practices and object-oriented programming, safety instrumented systems, enclosure design issues and challenges, process control advice
Edge Computing
This article collection contains several articles on how today's technologies heap benefits onto an edge-computing architecture such as faster computing, better networking, more memory, smarter analytics, cloud-based intelligence, and lower costs.
Data Center Design
Data centers, data closets, edge and cloud computing, co-location facilities, and similar topics are among the fastest-changing in the industry.
PLCs
Programmable logic controllers (PLCs) represent the logic (decision) part of the control loop of sense, decide, and actuate. Featured articles in this digital report compare PLCs and programmable automation controllers (PACs), industrial PCs, and robotic controllers.
SIDB

Find and connect with the most suitable service provider for your unique application. Start searching the Global System Integrator Database Now!

August 2018
SCADA standardization, capital expenditures, data-driven drilling and execution
June 2018
Machine learning, produced water benefits, progressive cavity pumps
April 2018
ROVs, rigs, and the real time; wellsite valve manifolds; AI on a chip; analytics use for pipelines
John O. Ayuk, PE, CFSE, PMP, CAP
Automation Engineer; Wood Group
Doug Baker
System Integrator; Cross Integrated Systems Group
Jose S. Vasquez, Jr.
Jose S. Vasquez, Jr.
Fire & Life Safety Engineer; Technip USA Inc.
Data Centers: Impacts of Climate and Cooling Technology
This course focuses on climate analysis, appropriateness of cooling system selection, and combining cooling systems.
Safety First: Arc Flash 101
This course will help identify and reveal electrical hazards and identify the solutions to implementing and maintaining a safe work environment.
Critical Power: Hospital Electrical Systems
This course explains how maintaining power and communication systems through emergency power-generation systems is critical.
Engineers' Choice Awards
The Engineers' Choice Awards highlight some of the best new control, instrumentation and automation products as chosen by Control Engineering subscribers.
System Integrator Giants
The System Integrator Giants program lists the top 100 system integrators among companies listed in CFE Media's Global System Integrator Database.
System Integrator of the Year
Each year, a panel of Control Engineering and Plant Engineering editors and industry expert judges select the System Integrator of the Year Award winners in three categories.
Design of Safe and Reliable Hydraulic Systems for Subsea Applications
This eGuide explains how the operation of hydraulic systems for subsea applications requires the user to consider additional aspects because of the unique conditions that apply to the setting
How to Maximize Factory Automation Efficiency with Low Cost Machine Vision
This eGuide illustrates solutions, applications and benefits of machine vision systems.
Wireless Reliability in Harsh Environments
Learn how to increase device reliability in harsh environments and decrease unplanned system downtime.
September 2018
Optimize controls via cloud software, ladder logic simulation, industrial wireless best practices
August 2018
Augmented reality and virtual reality education, autotuning PID control, cybersecurity advice, educating engineers
July 2018
Ladder logic best practices and object-oriented programming, safety instrumented systems, enclosure design issues and challenges, process control advice
Edge Computing
This article collection contains several articles on how today's technologies heap benefits onto an edge-computing architecture such as faster computing, better networking, more memory, smarter analytics, cloud-based intelligence, and lower costs.
Data Center Design
Data centers, data closets, edge and cloud computing, co-location facilities, and similar topics are among the fastest-changing in the industry.
PLCs
Programmable logic controllers (PLCs) represent the logic (decision) part of the control loop of sense, decide, and actuate. Featured articles in this digital report compare PLCs and programmable automation controllers (PACs), industrial PCs, and robotic controllers.
SIDB

Find and connect with the most suitable service provider for your unique application. Start searching the Global System Integrator Database Now!

August 2018
SCADA standardization, capital expenditures, data-driven drilling and execution
June 2018
Machine learning, produced water benefits, progressive cavity pumps
April 2018
ROVs, rigs, and the real time; wellsite valve manifolds; AI on a chip; analytics use for pipelines
John O. Ayuk, PE, CFSE, PMP, CAP
Automation Engineer; Wood Group
Doug Baker
System Integrator; Cross Integrated Systems Group
Jose S. Vasquez, Jr.
Jose S. Vasquez, Jr.
Fire & Life Safety Engineer; Technip USA Inc.
Data Centers: Impacts of Climate and Cooling Technology
This course focuses on climate analysis, appropriateness of cooling system selection, and combining cooling systems.
Safety First: Arc Flash 101
This course will help identify and reveal electrical hazards and identify the solutions to implementing and maintaining a safe work environment.
Critical Power: Hospital Electrical Systems
This course explains how maintaining power and communication systems through emergency power-generation systems is critical.
Engineers' Choice Awards
The Engineers' Choice Awards highlight some of the best new control, instrumentation and automation products as chosen by Control Engineering subscribers.
System Integrator Giants
The System Integrator Giants program lists the top 100 system integrators among companies listed in CFE Media's Global System Integrator Database.
System Integrator of the Year
Each year, a panel of Control Engineering and Plant Engineering editors and industry expert judges select the System Integrator of the Year Award winners in three categories.
Design of Safe and Reliable Hydraulic Systems for Subsea Applications
This eGuide explains how the operation of hydraulic systems for subsea applications requires the user to consider additional aspects because of the unique conditions that apply to the setting
How to Maximize Factory Automation Efficiency with Low Cost Machine Vision
This eGuide illustrates solutions, applications and benefits of machine vision systems.
Wireless Reliability in Harsh Environments
Learn how to increase device reliability in harsh environments and decrease unplanned system downtime.
September 2018
Optimize controls via cloud software, ladder logic simulation, industrial wireless best practices
August 2018
Augmented reality and virtual reality education, autotuning PID control, cybersecurity advice, educating engineers
July 2018
Ladder logic best practices and object-oriented programming, safety instrumented systems, enclosure design issues and challenges, process control advice
Edge Computing
This article collection contains several articles on how today's technologies heap benefits onto an edge-computing architecture such as faster computing, better networking, more memory, smarter analytics, cloud-based intelligence, and lower costs.
Data Center Design
Data centers, data closets, edge and cloud computing, co-location facilities, and similar topics are among the fastest-changing in the industry.
PLCs
Programmable logic controllers (PLCs) represent the logic (decision) part of the control loop of sense, decide, and actuate. Featured articles in this digital report compare PLCs and programmable automation controllers (PACs), industrial PCs, and robotic controllers.
SIDB

Find and connect with the most suitable service provider for your unique application. Start searching the Global System Integrator Database Now!

August 2018
SCADA standardization, capital expenditures, data-driven drilling and execution
June 2018
Machine learning, produced water benefits, progressive cavity pumps
April 2018
ROVs, rigs, and the real time; wellsite valve manifolds; AI on a chip; analytics use for pipelines
John O. Ayuk, PE, CFSE, PMP, CAP
Automation Engineer; Wood Group
Doug Baker
System Integrator; Cross Integrated Systems Group
Jose S. Vasquez, Jr.
Jose S. Vasquez, Jr.
Fire & Life Safety Engineer; Technip USA Inc.
Data Centers: Impacts of Climate and Cooling Technology
This course focuses on climate analysis, appropriateness of cooling system selection, and combining cooling systems.
Safety First: Arc Flash 101
This course will help identify and reveal electrical hazards and identify the solutions to implementing and maintaining a safe work environment.
Critical Power: Hospital Electrical Systems
This course explains how maintaining power and communication systems through emergency power-generation systems is critical.
click me