Hello,
We have an Otis 211 that we are getting intermittent STLD faults. Once we get to the site and reset it it will run for a couple of days or week then get another STLD fault. We have looked at some of the obvious things such as slowdowns, interlocks, valve(new)and selector. It is so intermittent we cannot nail down the actual cause. I ran the unit to every floor for 2 hrs with no hickups or issues. Does anyone have any suggestions.

Thanks

We had the same thing. Last things we did was physicaly check limit switches (both the contacts weren't quite right and the pivot) and also added some maxglide around packing. Ours seemed to mostly trip in middle of night or after sitting a couple of hours and then a slight rush of traffic, after these had no calls for over a month

It just a suggestion, try making the lowest landing your home landing for a month. Then check your stall time value, it may be set too low.

If the system has an over speed valve, that's worth checking.

Check the stall time. It should be set to 45 seconds for a normal floor height. If it has longer floors try increasing it. Also is the recycler working, it recycles to warm the oil up, if that's turned off it could just be cold oil after it sits for a while. Also try adding cat oil additive to the oil. It helps with the stiction issue.

Good point Magic!

Yeah like he said. Check and see if your unit has OLT and its enabled.

Funny I missed that after spending several hours running a unit to heat up the oil today! The manager was on vacation so no one called it in. And it was down since before Christmas...

99% of the time if your problem is not an interlock, it is you your L3S limit switch. The car will leave the bottom floor and the switch will not make. After a few runs, up or down, you stall out.

had same problem, never saw it happen car always ran fine, watched it for many hours, and many calls. we swapped tape reader, checked all switches, etc etc, even changed the main cpu board. after exhausting every possible solution, we changed the valve, and that did it. could not believe it was the valve, especially after running it so many hours, over the course of a month of calls, the valve never acted up while we were there. good luck

WPeak had same thing, selector magnets were sliding down off their tape and it would do it in the down direction leaving 4th floor. Check magnet positions. Been running like a champ for 2 years.

Yes definitely check your magnets. 211s are notorious for magnets moving. After checking them you may want to go around the edges with some clear silicon.