Hazardous Energy Control Procedures HECP

3 July, 2018

Trapped Key Interlocking

in Control Functions, Functional Safety, Hazardous Energy Control Procedures, Interlocks, Interlocks /

This is a trapped key interlock on the door of an electrical switchgear cabinet. To open the door the key must be inserted and turned to withdraw a bolt that holds the door closed. With the bolt withdrawn, the key is held in the lock. The upstream switching device is held open by another interlock using the same key; since the key can only be in one of the two locks, it prevents accidentally closing the upstream switch while the cabinet is open for maintenance. The interlock is attached to the door with one-way screws to discourage casual removal of the lock, which would defeat the system.

This entry is part 3 of 7 in the series Guards and Guarding

Many machine designers think of interlocks as exclusively electrical devices; a switch is attached to a movable mechanical guard, and the switch is connected to the control system. Trapped Key Interlocking is a way to interlock guards that is equally effective, and often more appropriate in severe environmental conditions. Copyright secured by Digiprove © 2018Acknowledgements: As cited.Some Rights ReservedOriginal content here is published under…

15 May, 2018

Five reasons you should attend our Free Safety Talks

by Doug Nix

in Events, Free Talks, Functional Safety, Hazardous Energy Control Procedures, Interlocks, Interlocks, ISO 13849, Lockout, News, Ontario, Pre-Start Health and Safety Reviews, Standards /

No Comments

Reason #1 – Free Safety Talks You can’t argue with Free Stuff! Last week we partnered with Schmersal Canada and Franklin Empire to put on three days of Free Safety Talks. We had full houses in all three locations, Windsor, London and Cambridge, with nearly 60 people participating. We had two great presenters who helped…

15 May, 2018

Q & A: Can Safety PLCs be used for Lockout?

by Doug Nix

in Functional Safety, Hazardous Energy Control Procedures, ISO 13849, Lockout, Ontario, Q & A /

3 Comments

This entry is part 2 of 2 in the series Q&A

The question of lockout and the use of safety PLCs as a means to meet the lockout requirements comes up more and more frequently these days. Can Safety PLCs be used for lockout? Safety professionals don’t always agree on this controversial topic! During the Free Safety Talks that we did with Schmersal Canada and Franklin Empire, this…

15 March, 2011

Updates to Popular Articles

by Doug Nix

in Canada, CE Mark, Control Functions, Emergency Stop, Hazardous Energy Control Procedures, Robotics, USA /

No Comments

This entry is part 8 of 16 in the series Emergency Stop

We’ve recently updated a couple of our popular articles! Check them out! Busting Emergency Stop Myths Reader Question: Multiple E‑Stops and Resets

28 February, 2011

Understanding the Hierarchy of Controls

by Doug Nix

in Canada, CE Mark, Complementary Protective Measures, Control Functions, Control Reliability, Emergency Stop, EU European Union, Functional Safety, General, Guards and Guarding, Hazardous Energy Control Procedures, Hierarchy of Controls, Interlocks, Interlocks, Lockout, Ontario, Risk Assessment, Robotics, USA /

8 Comments

The Hierarchy of Controls illustrated as an inverted triangle with each level of the hierarchy written one above the other, starting with Inherently Sfe design, then Engineering Controls, then Information for Use, then Administrative Controls and finally descending to PPE at the bottom. An arrow with the text "Effectiveness" on it runs parallel to the triangle and points downward from Inherently safe design to PPE.

This entry is part 4 of 5 in the series 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…

29 November, 2010

Using E‑Stops in Lockout Procedures

by Doug Nix

in Canada, Control Functions, Emergency Stop, EU European Union, Hazardous Energy Control Procedures, Lockout, USA /

4 Comments

This entry is part 6 of 16 in the series Emergency Stop

Emergency stop devices are sometimes, incorrectly, used as part of a lockout procedure for machinery. Learn more about how to correctly used these devices as part of Hazardous Energy Control Procedures for industrial machinery.

3 September, 2010

Busting Emergency Stop Myths

by Doug Nix

in Canada, Control Functions, Emergency Stop, EU European Union, Guards and Guarding, Hazardous Energy Control Procedures, International, Lockout, Robotics, USA /

7 Comments

This entry is part 5 of 16 in the series Emergency Stop

There are a number of myths that have grown up around emergency stops over the years. These myths can lead to injury or death, so it’s time for a little Myth Busting here on the MS101 blog!