[DrewADesign]

They effectively don’t do anything in most elevators in the US during normal operation. The ADA requires elevator doors remain open at least 3-seconds. Usually, people-moving elevators are most efficient when doors close as quickly as possible, so they start closing exactly at 3 seconds. I’ve used elevators with less common use cases — huge ones in hospitals, freight elevators, hotel service elevators — that might be configured to stay open longer than the 3 second minimum, assuming people will push the door close button as soon as they’re ready.

[b112]

Nothing you've said indicates why the button does nothing.

I can enter an elevator is under a second and push the button. This is doubly faster when not waiting for the doors to open fully, effectively making my button push at 0 seconds from door full open.

If you're saying "3 seconds is not long to wait, so it's the same as the button doing nothing", this is false, untrue, and I often use it.

Alternatively, requiring elevator door to wait 3 seconds as a default does not negate someone overriding that.

I've manipulated the button and seen timing differences. It does work. It does make a difference.

Did you mean something else?

[DrewADesign]

> Nothing you've said indicates why the button does nothing.

Let me expound a bit —

The close-door button cannot override the ADA minimum 3-second open time… the door must remain open for at least 3 seconds no matter what you press. But, most are configured to automatically close at 3 seconds. So as soon as the door-close function is no longer overridden, the door starts closing anyway, so pressing the button has no effect. With the door-open button and door sensor, they generally start closing immediately when they’re not active, so since the doors are already closing, the door-close button has no effect. If the door-open button is configured to open the door more than momentarily, the door close button should function.

If the elevator is designed to stay open longer than the 3-second period during which the door-close button is overridden, it will be available after the first 3 seconds. So if it’s configured to stay open for 10 seconds, the door-close button will be inactive for 3 seconds, but will start a door close, when pressed, from the 4th through the 10th second. At 10 seconds, the door will be closing anyway.

If a regular people-moving elevator is configured to be capable of closing the door in less than 3 seconds, it’s out-of-code. Since professional elevator companies maintain and configure most (all?) up-to-code elevators, and they’re probably liable for them to some extent, I doubt that’s common. It’s not like I’ve studied it or anything though.

I’m pretty sure that timing it out with a stopwatch would reveal that no matter what is happening, the door stays open for a minimum of 3 seconds. Anything beyond 3 seconds depends on how it’s configured, but most are configured to close as soon as they legally can.

[b112]

Well it's a good explanation, and I've just looked at the ADA requirements citing what you're specifying, but perhaps it's a case of older construction and time.

The 1991 requirements don't seem to mention this, and it wasn't until 2012? that the new rules came into effect it seems. And that's only for new construction or alterations. How many elevators are legacy? And it's not like I use elevators daily, I think the last time I used one was 2 years ago.

But an interesting dive into it. Thanks for responding cogently.