Emergency Stops

[mordred]

OHSA in Canada also specifies that E-stops cannot be covered

 

[TheStarr]

OSHA requires:

In accordance with 9.2.5.4.1,
emergency stop functions shall
be designed to be initiated by a​

single human action.

Check out the attachment from Omron, good info on a variety of electrical components.

 

[Kev77]

OSHA requires:

In accordance with 9.2.5.4.1,
emergency stop functions shall
be designed to be initiated by a​

single human action.


What does this mean? I can use one finger in a guarded PB. That is a single action.

 

[leitmotif]

Yup it sure is. However E stop has an additional requirement that is to latch (ie contacts open) in the SHUTDOWN position and require mechanical action (I believe two actions ie twist and a "pull" to reset.

Dan Bentler

 

[LadderLogic]

What does this mean? I can use one finger in a guarded PB. That is a single action.

As long as you don't have to lift a cover first, yes. Otherwise that would be two.

 

[JesperMP]

SICK ES21-AT1140:

 

[MartiniRossy]

We have been moving the E-Stops fromt the OIP's to a small enclosure mounted nearby. That has helped significantly with accidental E-Stops.

 

[silva.foxx]

In the past I have fitted keyed-release e/stops with keys issued to supervisors / teamleaders. The hassle it caused in getting the supe to release the e/stop was enough to prevent nuisance knocks of the button!

 

[kb9ttx]

For what it is worth, a good rule of thumb is that someone should be able to stop a machine in an emergency with nothing more than the bloody stump that is still attached. Adding covers or collars to emergency stop buttons are both presumptive and arrogant at least in my opinion.

 

[Protiusmime]

Training and Balance

Non-emergency use of E-stops can happen when operators are not sufficiently trained on their consoles. Well-designed systems should not rely on an operator's frantic dive-at-the-console move. Where I work, we relocate the E-Stops out of the grouping of and above the other controls, at a height where no one can lean over the E-Stop. When an accidental E-stop shutdown occurs more than a couple of times, some follow-up training is in order. There are other types of methods than a pushbutton, etc. And lastly... SAFETY FIRST. A few moments of downtime is far less a problem than compromising the safety systems.