Emergency Stop Switch

[wbd]

Hello,
Are there any requirements/standards for Emergency Stop Switches for equipment? These would used to shutdown a piece of equipment for a emergency, either equipment failure or a personnel in harms way situation.
Should they be spring action return or maintained and manually reset?
Thank You

 

[jraef]

It depends on where you are at. In the US and Canada it can be either, depending upon the design of your control circuit, but there are other standards that must be condisered such as lock-out / tag-out requirements etc. For instance if the E-Stop button is the only means of locking out the system, then it must be latched and have a key cylindar or some other lockable means. In IEC areas I believe it must always be latched in, pull to release in all cases.

"Venditori de oleum-vipera non vigere excordis populi"

 

[RalphChristie]

wbd

Sorry, I don't have any references, but in my opinion it would be beter if they are manually resettable. If the button is pressed, there is no way how the circuit could be energized without resetting the button. If the button is automatically resettable (spring action return), there is a chance for a remote start.

Regards
Ralph

 

[panelman]

We design our panels so that when an emergency stop is operated the stop must be reset AND then a separate reset must be operated, normally on the panel


This method is recommended (mandated?) in one of the BSEN standards we operate, all depends on the risk assessment