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What is an E-stop?

By: Luke Frey – Sales Manager at Rees, Inc.

The term Emergency Stop Switch may have several different formal definitions, depending on what resource or standard to which you are referring. I would summarize those various definitions by providing the following definition: An emergency stop switch is a device that, when actuated by an individual, performs an immediate shutdown of the equipment to which it is wired/programmed. Pretty basic concept, right? Things go wrong, people get worried, BOOM. Switch is activated, equipment is stopped, and crisis is hopefully fully averted. So how does Rees fit into the picture?

Rees manufactures push buttons, some of which fulfil the requirements of various Emergency stop switch standards. Some of these requirements may change based upon the equipment that is being used, so it is very important for users to know which standards apply to their intended use. Based upon the most common uses we see for our buttons, these are the most common requirements we come across:

  • Must have a yellow background
  • Actuator itself must be Red
  • The Contacts must be maintained – Meaning that when the switch is activated, it must be able to remain in that position until it is manually reset by an individual. (There is usually a button or handle on the switch that allows this to be done.)
  • The achievement of Normally Closed contact separation is the direct result of a specified movement of the switch actuator through non-resilient members. (example: NOT dependent upon springs)

There are other features that some of our customers prefer as well, such as:

  • Lockable Buttons – The ability to, once the device has been actuated, use a padlock, hasp, or some other form of locking device on switch in order to assure that it cannot be reset until the locking device has been removed.
  • Various Trip Forces – The determined amount of pressure, in weight, that it takes to actuate the switch.

In conclusion, I hope that this provides you with a more thorough knowledge of common e-stop requirements, as well as how Rees fits into the equation. If you have further questions about how Rees products may be used as e-stops on your equipment, please reach out to us and we will be happy to help you as best we can. If we are unable to fully understand the application or provide an answer, we have Sales Reps across the Midwest that will be happy to help as well. Be safe and thanks for choosing Rees.

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