Stephan Rose said:
Incorrect
I know what you are talking about...
Light curtain and nudge sensors....which are nothing but signals being
sent
to the controller.
Well, I'm by far not an expert on elevators but I know how mine works. The
"nudge" sensor (?), which for me, is a metal bar that runs the height of
both doors is a MECHANICAL switch that kills the drive to close the door.
Yes, it's up to the controller to open the doors however for a split second
there is no juice going to the door close drive. The controller senses this
problem and opens the doors. Even if the controller "WANTED" to keep
closing the door it can't. There's no power for it to while that bar is
depressed.
The only reason I know this functionality of my elevator is because it
broke. It's a "always on" form of protection and because it was no longer
on or able to function the doors would not close. It's also the first time
I got to see the inner set of doors closed with the outer set open. One of
those, "Ohhhhh, I get it", moments.
There are simply too many "backups" put in place. One I forgot to mention
is a resistance safety. If the doors are not able to "freely" close then
the controller will re-open. To test, wait for the doors to close and put
both palms of your hands on the outer part of the door and push inward.
With even a slight force the doors should open. With this however I see
your point, the controller is in charge.
Since you know a lot about it maybe you can answer a question for me.
We're told that when the doors start to open the elevator must be completely
stopped. Ours wasn't thus it failed inspection. So it got fixed. The part
I do not understand is since then I have always been aware of this. I've
been in MANY elevators where the doors are opening yet I see at least an
inch of movement between the elevator floor and the building floor. Granted
by the time even a 5 year old could fit through the door the movement has
stopped. Yet I see a brand new certificate posted inside. What's the real
story?