Home Forums General Discussion Technical Questions Dover LMH

...I am having a problem on a Dover LMH,can,t find why dda output is staying up all the time.this is causing issues with my retiring cam activating when it shouldn,t be..cannot determine from prints where this gets its feed..any help to put me in the right direction much appreciated..

Looks like DDA is the output that lights your down directional arrows. Doubt it is the cause of your problem, more likely a symptom or an unrelated shorted output.

problem being..this is a freight elevator with peelle doors..there are no direction arrows..unfortunately..this output is triggering the cd output with doors opened..

Is it possible DDA is mislabeled? I haven't worked on an LMH freight but I do see CD picks the RC for freight doors. Seems like the output still should be CD not DDA though. It sounds like it is using CD as if it has passenger doors, closing the door instead of picking the RC, is OPT12 set for freight doors?

It is possible that someone programmed the unused PLC output to do another function if there was a bad output. It's PLC ladder logic and if you have the IDEC program and interface it can be routed to another output easily. If someone did that and did not mark prints, trouble shooting can be very difficult unless you have the program and interface.

Unfortunately TKE considers the LMH obsolete now. The IDEC PLC is no longer supported by IDEC and they do not manufacture the modules or power supply anymore. Vertical express(TKE parts) did have some remaining stock on the modules and some other parts a year or 2 ago when I needed an output module, but I was told after their stock is gone they have no way of replacing it. They are telling all their customers who have the LMH and the LMT(traction) controls to look at modernization as they don't plan on supporting this product anymore.

So you may want to suggest that your customer look at modernization as well just due to parts issue with these controls. But I will say the LMHs I have maintained have been very reliable for the most part, it just comes down to that one day you will need parts.

Thanks,powerspike took out the cpu,as well as the option12 in the RAM. for freight elevator control,driving the cd,rc outputs crazy.
this was a good one.Vertical Express has total said there is no suport for this equipment..need to backup data for future problems.

I work 4 tke and we can't get nothing for these,was told by my office to make a list of all lmh's for sales guy

Ya me too, last time we needed a relay board they wouldn't give us one until the branch manager told them we had a signed MOD proposal.

And then they don't want us fixing bad traces in the field anymore. It's one of those "I can't tell you you can fix that board but if that elevator is back in service today I don't think we have a problem"