17 replies to this topic

[ceo]

Apparently happened this morning, local time. Might be disturbing to watch.
https://www.youtube....h?v=EcPTcQpkso4

[k2skier]

What lift manufacturer?

[Jonni]

Looks like a Dopp. I think I read it was installed in 2009.

[MNSkier]

Here is the latest: https://liftblog.com...dauri-rollback/

Can someone explain to me on a modern Dopp how it one would make an error so grievous that it would cause a rollback? It seems to me that the safety interlock systems would prevent something like this, or the actions would need to be quite deliberate to allow this to happen....

[Aussierob]

If you were attempting to operate the lift in Evacuation mode and weren't well trained on the procedures, it's possible to pump the brakes off, and either not know how to reapply them or panic.

[2milehi]

Typically on most North American Doppelmayrs the "Evac" mover needs two of the three brakes opened manually (Emergency or Service and Rollback). The Evac operator(s) then throttle up the Evac engine and push the lift through the brake. This action tells the operator that the Evac has the load and the Emergency or Service brake can be opened manually).

A lot of the safeties are bypasses in this mode. We practice the Evac on all of our lifts monthly, mechanics and electricians.

Europe could be doing it differently, we'll soon find out.

This post has been edited by 2milehi: 25 March 2018 - 11:25 AM

[Allan]

2milehi, on 25 March 2018 - 11:23 AM, said:

Typically on most North American Doppelmayrs the "Evac" mover needs two of the three brakes opened manually (Emergency or Service and Rollback). The Evac operator(s) then throttle up the Evac engine and push the lift through the brake. This action tells the operator that the Evac has the load and the Emergency or Service brake can be opened manually).

A lot of the safeties are bypasses in this mode. We practice the Evac on all of our lifts monthly, mechanics and electricians.

Europe could be doing it differently, we'll soon find out.

This seems odd to me. Our 2007 4CLF Doppelmayr has a fully operational braking system and safety system (running on only the second PLC, so none of the software generated faults) in evac mode. Is this not the norm? Which is similar to the rest of our equipment, with the exception of two lifts that we have to manually open the service brake.

[comeagain?]

Allan, on 25 March 2018 - 07:25 PM, said:

This seems odd to me. Our 2007 4CLF Doppelmayr has a fully operational braking system and safety system (running on only the second PLC, so none of the software generated faults) in evac mode. Is this not the norm? Which is similar to the rest of our equipment, with the exception of two lifts that we have to manually open the service brake.

The idea of manually bypassing safeties and opening brakes that will not re-close in the event of a rollback seems very strange to me. I can't imagine designing a control system that meant a process that will eventually happen with guests on the lift. Sure, have some provisions in case the PLC explodes in the panel, but as SOP, we're bypassing safety functions?

[2milehi]

Allan, on 25 March 2018 - 07:25 PM, said:

This seems odd to me. Our 2007 4CLF Doppelmayr has a fully operational braking system and safety system (running on only the second PLC, so none of the software generated faults) in evac mode. Is this not the norm? Which is similar to the rest of our equipment, with the exception of two lifts that we have to manually open the service brake.

Curious, is the PLC in your Doppelmayr an Allen Bradley?

[2milehi]

comeagain?, on 26 March 2018 - 04:45 PM, said:

The idea of manually bypassing safeties and opening brakes that will not re-close in the event of a rollback seems very strange to me. I can't imagine designing a control system that meant a process that will eventually happen with guests on the lift. Sure, have some provisions in case the PLC explodes in the panel, but as SOP, we're bypassing safety functions?

Not all the safety functions are bypassed. Only tower faults, Emergency stops, and grip profile faults can stop a lift. The Evac is typically only used when the PLC goes south. All of our Doppelmayrs (seven of them) can Evac in reverse so rollbacks are bypassed.

This post has been edited by 2milehi: 26 March 2018 - 05:12 PM

[Lift Dinosaur]

2milehi, on 26 March 2018 - 05:12 PM, said:

Not all the safety functions are bypassed. Only tower faults, Emergency stops, and grip profile faults can stop a lift. The Evac is typically only used when the PLC goes south. All of our Doppelmayrs (seven of them) can Evac in reverse so rollbacks are bypassed.

Sounds like you are talking about your detaches. Is it the same for the Wayback (4CLF)?
Thanks-
Dino

[comeagain?]

2milehi, on 26 March 2018 - 05:12 PM, said:

Not all the safety functions are bypassed. Only tower faults, Emergency stops, and grip profile faults can stop a lift. The Evac is typically only used when the PLC goes south. All of our Doppelmayrs (seven of them) can Evac in reverse so rollbacks are bypassed.

What's happening to your PLCs that you have to evac the lift?

[Allan]

2milehi, on 26 March 2018 - 05:07 PM, said:

Curious, is the PLC in your Doppelmayr an Allen Bradley?

Both of them in the lift are. The evac drive is a small diesel motor that couples to the driveline via a chain coupling.

[2milehi]

comeagain?, on 26 March 2018 - 05:33 PM, said:

What's happening to your PLCs that you have to evac the lift?

Two of the three times we've evaced guests off was due to no fault annunciation from the PLC. It is a royal pain in the dick to figure out what the fault is when there is no annunciation.

We have had some close calls with the Pilz PLC having an FS issue. It takes about 20 minutes to pull the stack, decode it, and hunt down the problem. Typically if we can't get a lift going in 20 minutes, the lift is evaced to get the people off.

In the off season I'll mess with the wiring of the clocked signal to paddle switches in the terminal and have the boys chase that issues. It can take them a couple of hours to find my induced fault.

This post has been edited by 2milehi: 27 March 2018 - 07:07 AM

[2milehi]

Lift Dinosaur, on 26 March 2018 - 05:22 PM, said:

Sounds like you are talking about your detaches. Is it the same for the Wayback (4CLF)?
Thanks-
Dino

Wayback is also included with the other detachables. The evac acts very simalar to the detachables.

[Lift Dinosaur]

2milehi, on 27 March 2018 - 06:48 AM, said:

Wayback is also included with the other detachables. The evac acts very simalar to the detachables.

Thanks!
Dino

[2milehi]

Allan, on 26 March 2018 - 05:51 PM, said:

Both of them in the lift are. The evac drive is a small diesel motor that couples to the driveline via a chain coupling.

Sounds like you got the Canadian built lift in that time period (mid 2000s) where St. Jerome went rouge and offered AB PLCs. I recall that Doppelmayr (Austria) in 2008 put that to a stop an only offered Pilz PLCs.

[comeagain?]

2milehi, on 27 March 2018 - 06:42 AM, said:

Two of the three times we've evaced guests off was due to no fault annunciation from the PLC. It is a royal pain in the dick to figure out what the fault is when there is no annunciation.

We have had some close calls with the Pilz PLC having an FS issue. It takes about 20 minutes to pull the stack, decode it, and hunt down the problem. Typically if we can't get a lift going in 20 minutes, the lift is evaced to get the people off.

In the off season I'll mess with the wiring of the clocked signal to paddle switches in the terminal and have the boys chase that issues. It can take them a couple of hours to find my induced fault.

Wow. Yeah, I'd say that's a good reason to not want people on the lift. And sounds like poor programming if you get faults or something without the PLC actually telling you what.