

Emergency Shutdown...Emergency Stop
#21
Posted 24 August 2012 - 06:57 PM
#22
Posted 25 August 2012 - 03:17 AM
Ultimately it is not the maintenance personnel, owners or the manufacturers who have created this issue; we really need to look at the ANSI committee.
The committees that draft the codes ultimately end talking about liability, now we are talking lawyers. Regardless of the intensions, the codes final outcome is about liability, not always functionality.
We had this same issue when B77 came up with the RPD’. I for one, what with the higher speeds that the lifts are being operated to today defiantly, will not dispute the need for an RPD system. But with that said at the time the RPD requirement came into effect, there was not a switch able to perform all of the functions required by the new code, they just went ahead and wrote the code in then left it up to the manufacturers to design a system. Keep in mind most of the codes that fall into the electronics category have a grey area for interpretation, and EVERY manufacturer will interpret the design parameters differently. Therefore we end up with different operational characteristics between manufacturers.
So as I see it there are two choices 1. Train your operators properly on your system (contrary to many opinions it is possible) and 2. Talk with your manufacturer and ask for a remote stop station that would be directly adjacent to your operator and make the switch you want used clearly obvious to your personnel. Then again with some of the electronically minded personnel at each area, come up with your own. As long as a station, as required by code, is near the operator, your authority having jurisdiction should not have a problem with a secondary station or single switch prominent on your existing station, then again I could be wrong, I have been once or twice before. From some of the comments I have seen it may be a worthwhile endeavor.
This post has been edited by chasl: 25 August 2012 - 03:25 AM
#23
Posted 27 August 2012 - 07:07 AM
vons, on 24 August 2012 - 06:57 PM, said:
My solution to this was to place the e-stop button off-plane - that is, at the top of the station. Easy enough to distinguish the two when done this way.
The state still insisted that the e-stop have a guard around it though. The photo shows an older version that uses the standard "cup guard". I have since changed them to the chrome rack handle scheme - much less costly and far more practical. The second photo shows these button guards.

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#24
Posted 27 August 2012 - 08:45 AM

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Going back to the very first post using the picture as the reference…Hummm even I am confused, perhaps the questions is somewhat misleading, isn’t the label Emergency Shutdown a visual light (not an actual stop button) that indicates some type of Emergency Stop has occurred?
…and adding to the confusion it would seem if that if that is true there are now two indicator lights for that condition (see the Christmas tree indicators).
Bud - I like the pedestal layout.
#25
Posted 27 August 2012 - 08:53 AM
Kelly, on 27 August 2012 - 08:45 AM, said:

Going back to the very first post using the picture as the reference…Hummm even I am confused, perhaps the questions is somewhat misleading, isn’t the label Emergency Shutdown a visual light (not an actual stop button) that indicates some type of Emergency Stop has occurred?
…and adding to the confusion it would seem if that if that is true there are now two indicator lights for that condition (see the Christmas tree indicators).
Bud - I like the pedestal layout.
Which one?
#26
Posted 27 August 2012 - 05:17 PM
Kelly, on 27 August 2012 - 08:45 AM, said:

Going back to the very first post using the picture as the reference…Hummm even I am confused, perhaps the questions is somewhat misleading, isn’t the label Emergency Shutdown a visual light (not an actual stop button) that indicates some type of Emergency Stop has occurred?
…and adding to the confusion it would seem if that if that is true there are now two indicator lights for that condition (see the Christmas tree indicators).
Bud - I like the pedestal layout.
every panel on that lift has that button, even the AUX start panel in the motor room has it too. Every panel on this lift has the emergency shutdown button.
Its not just this lift, its on all the panels that were being manufactured back at Doppelmayr's office for the upcoming installations.

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It is part of the christmas tree on the low voltage panel (Drive station) for both terminals.

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edits: added pictures
This post has been edited by SkiLiftsRock: 27 August 2012 - 05:22 PM
#27
Posted 03 September 2012 - 11:48 AM
4 stop buttons makes sense if they are to be used by a mechanic however 4 different stop switches seems like utter madness for a lift operator.
Any advantages of stop selection are overshadowed by the time it would take to make a decision on what stop to select…hummmm do I select stop #17…ah hell just hit emergency cause it gives me a 10 minute break until the mechanic shows up to reset the system.

#28
Posted 05 September 2012 - 06:00 PM
Kelly, on 03 September 2012 - 11:48 AM, said:
4 stop buttons makes sense if they are to be used by a mechanic however 4 different stop switches seems like utter madness for a lift operator.
Any advantages of stop selection are overshadowed by the time it would take to make a decision on what stop to select…hummmm do I select stop #17…ah hell just hit emergency cause it gives me a 10 minute break until the mechanic shows up to reset the system.

Yeah...too many choices. What Razvan described in the second post made sense with the different ways of stopping the lift, but has there been an incident where if the "Properly Trained" operator could have used the stop for such emergency? maybe not. ANSI might just be trying to to what is safe and have the best of options for any emergency situation.
Razvan's quote: Emergency shutdown: motor is shut down (power to it is shut down, i.e. its contactor is opened), then service or emergency brake (or both; check your manual) is applied immediately, bringing the lift to a more aggressive stop.
#29
Posted 06 September 2012 - 11:07 AM

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Simple fix to it all!!! Simpler times. Recent find at a defunct MI ski area
#31
Posted 09 September 2012 - 02:32 PM
2milehi, on 08 September 2012 - 06:01 PM, said:
Score one for the French!
#32
#33
Posted 09 September 2012 - 06:39 PM
Lift Dinosaur, on 09 September 2012 - 06:00 PM, said:
Dino
10-4. My oversight.
#34
Posted 23 March 2017 - 09:05 AM
#36
Posted 23 March 2017 - 04:17 PM
What kind of wear/damage can happen to braking systems with that kind of forceful "stop NOW" application? I can't imagine they'd take very many applications, stopping a fully loaded lift, until they'd wear down pretty significantly. That's a heckuva lot of energy to dissipate. Consider also, not only do those systems have to stop the lift, but they have to hold it, too, to prevent a rollback.
#37
Posted 23 March 2017 - 04:46 PM
fireonthemountain, on 23 March 2017 - 09:05 AM, said:
I don't know the B77 at all, but we've had this requirement in the Z98 for a while. I always thought the engine shutdown was more to protect the employees and machinery if something were to go sideways.
I'd chat with Doppelmayr if your lift still has their controls running it - it may be a simple solution.
#38
Posted 23 March 2017 - 04:55 PM
_litz, on 23 March 2017 - 04:17 PM, said:
What kind of wear/damage can happen to braking systems with that kind of forceful "stop NOW" application? I can't imagine they'd take very many applications, stopping a fully loaded lift, until they'd wear down pretty significantly. That's a heckuva lot of energy to dissipate. Consider also, not only do those systems have to stop the lift, but they have to hold it, too, to prevent a rollback.
If the operator stopped it - they can reset, here anyways.
No damage should happen from any stop. Slight wear on the brake pads (they can last for years under normal operating and testing.) It's not necessarily a stop now application, especially on an unloaded or downhill loaded lift - where E-Shutdowns can actually be longer than a normal stop. An uphill loaded lift will stop itself pretty quickly without any braking power. These systems are designed to be used to stop and hold and should be tested regularly to make sure they do. This is all based on our equipment.
#39
Posted 24 March 2017 - 11:08 AM
I would personally like to see
- "Stop" - Used in most situations like a misload, at the end of the day, or other common stops. Ops can restart like normal.
- "Emergency Stop" - Used to stop NOW. Life or death type situations or when other controls aren't working, and should ideally never be used (except during testing). I would expect it to cut power to the drive. Ops can still restart, albeit probably different procedures.
If the PLC has multiple ways to slow/stop the lift in different situations it is stopping automatically, that's great. But the operator controls should be consistent in whatever method they trigger.
_litz, on 23 March 2017 - 04:17 PM, said:
On the lifts that I ran this season (All old Riblet doubles), ops can reset emergency stops. They are all labeled "Emergency Stop" but also have older labels that say "Emergency Shutdown". The only exception is the lift that requires you to manually pump up the emergency brake.
#40
Posted 24 March 2017 - 04:37 PM
In case of emergency, nobody should have to think .. it should just be instinctual.
A good example of this is locomotives : there's no big red button for an engineer to push called "Emergency Stop".
Instead, if you advance the brake lever fully, there's "full brake", and then, after a slight detente, there's "emergency brake".
What's the most instinctual thing you do when you want to stop NOW? you slap the brake on FULL (just like your car, when you stomp the brake). This design simply ensures that when you do that instinctual action, it takes care of the emergency application for you.
I can easily see how those consoles with all those multiple stop modes can be quite intimidating ....
In many applications, all over various industries, many operators just want a "go" button and a "stop" button, so they don't have to think.
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