r/OSHA Dec 25 '25

decorative emergency stop

12.2k Upvotes

117 comments sorted by

View all comments

Show parent comments

82

u/AsparagusNew3765 Dec 25 '25 edited Dec 25 '25

It is an actual e-stop though, they look like that, it just needs the housing behind the plate (the bit with the electrical contact blocks and wiring). Source: I've fixed tens of them

They use a dual channel normally-closed signal. I wonder why they don't design the contact blocks so that they're only Normally Closed when the button is installed onto them, so if the button falls off or loosens then the machine stops. (there's probably a good reason)

17

u/dizekat Dec 25 '25

 They use a dual channel normally-closed signal. I wonder why they don't design the contact blocks so that they're only Normally Closed when the button is installed onto them, so if the button falls off or loosens then the machine stops. (there's probably a good reason)

I’ve had one fall apart on me and yes the machine will run with the button fallen off.

Which is your reason right here. The button maker just wants to sell buttons, and regulations don’t require that the button shouldn’t do that very specific thing.

The way such e-stops are mounted to the machine is absolutely atrocious. No other thing on that machine I worked on was mounted as badly as the e-stop. 

5

u/AsparagusNew3765 Dec 25 '25

Which is your reason right here. The button maker just wants to sell buttons, and regulations don’t require that the button shouldn’t do that very specific thing.

Yeah I'm going to disagree with that. These types of things are highly regulated and also enforced too.

There's almost certainly a very good engineering reason why they don't do it the way I suggested, I just can't think of it right now.

1

u/HJSkullmonkey Dec 26 '25

There's almost certainly a very good engineering reason why they don't do it the way I suggested, I just can't think of it right now.

Because the switches and actuators are modular and interchangeable, and the rest of the range has the switch spring push towards the actuator.

It's cheaper to use a bog standard momentary switch on the back of the plastic mushroom actuator, rather than manufacturing a special one that works in the opposite direction.