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Elevator breaker intermittently tripping.

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I've got a senior citizen 4 story condo complex that I do service work for, with an elevator that has been causing me troubles for the past year.

6pm on Thanksgiving (Canada) 2021 I received an emergency call that the elevator at this building had stopped working. I was closer than the elevator guy, so I went there to see if I could get them out. I found that the breaker feeding the elevator had tripped. Everything checked out, so I reset the breaker and all was well. I could not find anything that would cause the breaker to trip nor could I replicate the issue, and I assumed that the breaker itself might be the problem. I didn't have a replacement (NA Stabloc 3P 100A), but I did have two 2P 125's that I made work for the weekend until I could get a replacement.

No new replacements were available, but I did find one that was used and in good condition. I installed that 'new' breaker and it's been working without fail until yesterday when I received another call that the breaker had tripped on six different occasions over the previous 2 days.

This time I was able to replicate the issue. I would run the elevator to the top floor twice in quick succession. The second time, just as the elevator would near the 4th floor, the breaker would trip. I repeated the test and got the same results.

I checked every wiring connection in the elevator control box, disconnect, and panel. I meggered the motor and the wiring and found no issues. I IR scanned the breaker, contactors, and disconnect for hot spots and saw nothing abnormal. The panel bus shows no signs of overheating or arcing.

I hooked up the power meter and ran the elevator a few times to see if anything would show up there. The voltages are consistent (212V idle, 210V under load), and the current values are close as well. There's a short inrush spike at startup (131A) which settles to 64A for the first 2 floors. It drops to 58A at about the 3rd floor, and stays there until it reaches the top. On the second run everything is identical, except that the breaker trips right before the elevator reaches the top (58A). No spike in current or dip in voltage. The breaker stays cool to the touch, and the IR doesn't show any abnormal heat either.

Not sure what else to tell them other than I need to find another breaker. I swapped out the 100A for the jury rigged 125's again and ran the elevator 4 times up and down without fail.

Any other ideas?
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· Registered
Residential, lite comm., Industrial
5,473 Posts
elevator is about 40 yrs old, unless its been replaced.. the car and the guides will have significant wear
if the elevator is able to move around sideways in the shaft (loose, worn out fit in the shaft way), it may be missing or hitting a limit switch or some such control
take a ride in it and pay attention to bumps or bangs in the ride
at any rate i would get out of that situation and call in some experienced elevator guys and leave it to them

· Registered
Residential, lite comm., Industrial
5,473 Posts

Here’s a really simple way of getting it done.
if you grew up using that it would be fine

but here osha and a host of others would not allow it
for a good reason, those are very disconcerting the first time you get on it
almost everyone would get injured badly the first time they tried it as an adult

my first was when i was in my early 30s in a boiler complex in a paper mill
it did not even have enclosed cars, just a simple conveyor belt with a standing platform and a hand hold about chest high
no way to stop it in an accident and no way to live through the basement or over the top
you had to get it right on the first and every try
i was extremely nervous and watched it go by for a bit before i ever tried it
i never did like it

· Registered
Residential, lite comm., Industrial
5,473 Posts
it began on about the fifth or higher floor and only went up 1 floor
it was moving slightly faster than the one in the video
the alternative was stairs all the way down, then walk around to more stairs up the rest of the way

i was doing an electrical motor driven equipment survey at the time and needed to keep track of which floor i was on
i was not familiar enough to be sure i restarted on the correct floor if i used the stairs, no other way to know which floor, no signs
in a cpl days i was past that point far enough to find the stairs down and be able to keep track of the floors again
part of the deal with the other stairs was they did not always connect to every floor on the way up, which is why it was difficult to keep up
there were also occasional partial levels that they did not want to call a full level and number it

all in all, it was challenging just to keep up with where i was, and occasionally how to get back lol
after spending a full morning walking around and around just one level and looking to see if i missed anything
my head sometimes got turned around for a minute
a few sets of stairs going down were dead end after a cpl levels
there were somewhere around 15 or 20 levels, some had motors, some did not

the entire complex contained three complete boilers, one was gas fired, then bark fired, then black liquor fired
each was built some years after the other, gas was really small package boiler, bark was bigger, black liquor was huge

black liquor is mostly concentrated pine sap resulting from refining the paper pulp, it also has a lot of lime and some other chemicals in it
the boiler's primary purpose was to recover the lime and reuse it in the process
the boiler actually had no bottom in it so that the nearly pure lime would precipitate down to the bottom to be recovered by conveyors etc.
the liquor was sprayed into the fire chamber with high pressure injectors to make a mist that would burn

before they built that boiler, they separated the sap and lime without burning the sap and made what they called tall oil (pronounced towel, dont ask me why)
this was sold to make turpentine and such, the story went that that portion of the mill alone would earn the payroll every week (who knows for sure)

about 10 yrs ago they built a new liquor boiler and the old one was mostly abandoned or scrapped, although some few things were still used as part of the gas and bark systems

quite the novella .... eh ?
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