PushButtons Extended Vs Flush

What are things to consider when choosing between extended vs flush pushbutton types?

Kid

As example switch handles are required to be OFF in DOWN position - thinking is that if something falls and knocks switch to DOWN the safest is to turn off.

Somewhat same thinking for flush vs exposed
E stop or "regular" stop buttons in my mind should always be exposed. Starts etc should always be flush to prevent erroneous starting.

Operators will probably prefer the exposed because they can hit them with a broom from across the room. That is the main reason I NEVER use them when possible. Yes I am mean and rotten and just cannot stand them sitting in their chair - my justification for my hard heart is they need the cardio vascular exercise.

Electrically I do not think it makes any difference.

Dan Bentler

What's more critical or dangerous? A machine suddenly unexpectingly starting or one stopping. In most cases it is more important that machinery doesn't start unexpectedly and it takes a required conscious effort to start it. So, a flush mount is used so that the operator has to push it with his finger and not slap at it or accidentally lean on it. The stop on the otherhand is often extended so that it can be slapped at quickly to stop the machine. It could be argued however, that the kind of quick stop like that should be done with a mushroom head easily accessible and that a controlled stop (again taking a conscious effort) could also be flush too.

Another reason to use an extended head, although I don't like them, is for maintained stop. You can buy an adapter that once you push the extended head in, your flip it over the PB and it holds it in. Again, I'd rather use a maintained push/pull mushroom head for that. Some people use these for maintained jog too (with the flip adapter) and I REALLY think those are unsafe, unless you have readily accessible pull cords everywhere.

The Plc Kid said:

What are things to consider when choosing between extended vs flush pushbutton types?

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Extended when you want to make it easy for the operator.
Flush when you want to make it hard.

We use the hmi for maintined jog and mushroom head buttons for estops.

So it sounds like flush is the way to go for me. Thanks for the advice Guy's

the flush also break less

Dirty environment?
The flush is harder to clean when the button gets stuck.

leitmotif said:

Starts etc should always be flush to prevent erroneous starting.

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In many of the remaining sites in the lumber industry, we use 3 position push-pulls, push to stop, pull to start. Fewer buttons on the panel.

leitmotif said:

Operators will probably prefer the exposed because they can hit them with a broom from across the room.

Dan Bentler

Click to expand...

Dan, also in the lumber industry, operators that have a pickeroon handy, prefer to have the flush buttons.

A pickeroon is a tool made from an axehandle and has a metal hook on the end. It is used much like a fisherman would use a gaff, except it has less hook more like a pickaxe. They snag the item and pull it to them.

The reason they prefer the flush buttons is because that way the pickeroon hook point does not slide off an exposed button. the ring holds the pickeroon on top of the button!

Did a few sawmill inspections
Dang if they are not the coldest place on earth in winter.

Know picaroon well. They like the flush huh? Always thought sawmill workers were an unique breed of cat.

Dan Bentler

I always use flush - harder for a careless loose arm to bump a button and turn off a critical process. Also use protective rings on E/stops - nothing worse than a telephone exchange or data centre running merrily on generators when there is a power outage and someone bumps/leans against an E/stop and shuts downs the generators!