[Noisebridge-discuss] Elevator repair

Jake jake at spaz.org
Tue Feb 1 14:12:06 UTC 2011

Okay so Monday night, Rachel and I climbed through the hatch in the 
cieling of the elevator, just like in the movies, and stood on top of the 
thing to figure out why it doesn't let itself be called when it's there.

I was right that there is a switch activated when the elevator is at the 
top of its travel, but that's like a foot higher than our floor and is not 
being triggered.  The button that is being triggered is the same kind 
however, and is in a metal junction box and its arm has a roller bearing 
on it and is very serious like you would expect.


My theory now is that inside that junction box is either one Dual-Pole 
microswitch (two sets of contacts) or two separate microswitches, and one 
of them is failing intermittently.

One of them makes the elevator stop at our floor, and is working.  The 
other tells the system the elevator has arrived and is ready to go and is 
not making contact all the time.  Apparently this also happens on the 
second floor.

I say the solution is to open either the safety switchbox above and 
examine the microswitches inside, and order two or three of them, or do 
the same to the actual switchbox that stops our elevator which presumably 
has the same switches in it anyway.

When we open the switchbox below it, whether to examine it or to put in 
the new switches (buttons technically) we will do so by moving the 
elevator down from our floor, hit STOP after a couple of feet, and then 
climb out the ceiling hole to access the switchbox of our floor by 
standing on top of the elevator again.  Because we can't access the 
switchbox while the elevator is properly stopped on our floor.

There is a mechanism to prevent opening the internal gate of the elevator 
when not on a proper floor but it doesn't work, and if it did we could 
easily bypass it by tugging a cable on top of the elevator while opening 
the gate, so that elevator repairpersons could take a break and get a 
kombucha while not finished fixing the elevator, while it's 2 feet low.

Note that when i say switches, i am talking about momentary switches also 
known as buttons, most likely "micro switches" made of Bakelite with a 
lever arm and a clicky noise, but we won't know until we open one of the 
boxes.  I should have done that Monday night (the topmost box) and taken 
pictures so that someone could go to the elevator parts store.  Whatever.

Someone should make an elevator repair wiki and put these posts on it.


> Wait you debugged the elevator?  Let's fix it then!  Having it actually
> work properly would be the best solution.  I'll be happy to be the one
> to Do it if you can show me this microswitch of which you speak.

i am just mentally picturing the problem.  The elevator comes to our
floor, which is the top floor, and there's a button "A" on the rail to
keep it from going too far.  There is another button "B" which tells the
system that it's on the third floor, and is ready to be called to another
floor because it's done moving around.  The button "A" is being triggered
before button "B" and the elevator stops moving before it really "arrives"
at the third floor.

When one goes in there and presses the 3 button again, the button bypasses
the stop switch for long enough to run the motor enough to bump it up a
quarter-inch until it presses button "B" telling the system it's arrived
at the third floor and everything is okay.

It might not be as simple as adjustment however, because it could be that
the capacitor or diode protecting the buttons' contacts from the inductive
kick of the relay it triggers has failed to protect the button contacts,
and the button needs to be replaced.  Only an elevator-repairfolk will
have the exact correct replacement button, and really know how to adjust

As much as I would be okay with getting covered in grease and mouse-shit
trying to find both buttons and adjusting them, and hoping that the
problem is only adjustment (which is slightly unlikely) i think it's
probably better to have the repair made by the professional.  However if
the landlord/property owner flat-out says that they'd rather us try to fix
it first, we should go for it.

But at this point, with the elevators' behavior properly sussed out (the
note on the door is excellent) it should be easy for a repairperson to do
the job without wasting too much time.


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