Skilifts.org / SORT Forum

Hello,

I was wondering if anyone knows the diffrence between "Emergency Shutdown" and "Emergency Stop" on the same panel.

Thanks!

See attached picture

Remembering from my former Doppelmayr 8-MGD:

Regular stop: electromagnetic braking with about -0.4 m/s² (DC motor shortly works as a brake, generating power -- returned to the grid or dissipated as heat), service brake applies when speed is less than 0.2 m/s, motor is simultaneously shut down. Gentlest stop.

Emergency stop: electromagnetic braking with about -0.6 m/s², service (or emergency, see the manual) brake applied when speed is less than 0.2 m/s, motor is simultaneously shut down.

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.

Your case my differ, depending on local regulations and changes in the maker's philosophy ("changes" is a more accurate word than "advances").

Thanks Razvan for the information!

I was told for this installation it was state code to have it.

Although many and most lifts are different depending on the vintage ,manufacturer , upgrades etc . Here is my spin on the control panel . A few years ago the "e- stop" button was changed to "emergency shutown" button, same thing just semantics (ANSI requirement). On the panel pictured, there are two types of push buttons on the panel , maintained and momentary. On 90s vintage Dopp's they had a service stop button that was a momentary button. This stop was not a re-gen stop but a stop that was decelerated and stopped by the service brake ( high speed brake) alone, My point being that the emergency shutdown stop button in the photo looks a lot like a momentary button. ANSI requires a maintained switch on the emergency shutdown switch. the E-Stop button looks like a maintained button.. . E- stop and Emergency shutdown to me mean the same thing , remove the energy from the motor by opening the line contactor and stop the lift with the low speed brake and at nearly zero speed apply the service brake( highspeed brake) . What vintage lift is this?

aug, on 13 August 2012 - 04:35 PM, said:

This is Orange Bubble Express, Canyons resort Park City Utah.

In attached picture is a 1996 Doppelmayr low voltage panel drive station with the service stop in the middle.

 IMG_1285.jpg (1.35MB)
Number of downloads: 169

Looking at another picture from the same lift (Orange Bubble) there is a "Stop SB" like the one pictured in the 1996 lift panel.

 IMG_2062.jpg (1.28MB)
Number of downloads: 128

You know what? This type of control presentation overtaxes the intelligence of the average lift operator.
Poor design, I say. Electrical engineers do not operate tramways. Go back to human-machine interface school.
This post has been edited by Emax: 13 August 2012 - 05:26 PM

On the same note ...like the fire alarm or fire ext . behind glass the sign says " In emergency, Break glass" And then????
This post has been edited by aug: 13 August 2012 - 05:39 PM

This is not only applicable to a vintage lift, my lift was built in 2007 and the external panels looked the same. Indeed the Emergency Stop mushroom is a maintained button.
Gentle stop (like the stop one makes at the end of the day, when last tourists get down from the last gondola) and an emergency stop, which applies both brakes for the case when the cable derailed or someone's head is about to be caught in a closing door. I can't see no need for any other stopping method.

Here's an excerpt from the manual:
" There are five ways of stopping the lift (SA1 – SA5):
SA1 = Stop:
Activated by pressing one of the stop buttons or by the stop circuit. The drive will
slow down automatically within a preadjusted time (electrical brakes; a=-0,4m/s²).
When the drive motor reaches minimal speed (0,2m/s) the service brake comes
into operation and the main drive will be shut down.
SA2 = Emergency Stop:
Activated by pressing one of the stop buttons or by the stop circuit. The drive will
slow down automatically within a preadjusted time (electrical brakes; a=-0,6m/s²).
When the drive motor reaches minimal speed (0,2m/s) the service brake comes
into operation and the main drive will be shut down.
SA3 = Stop-SB:
Activated by pressing the Stop-SB button on the control panel of the drive station
or by the Stop-SB circuit. The drive will shut down immediately and the lift will be
brought to a standstill mechanically by the service brake (a=~-0,3m/s²).
SA4 = Stop-EB:
Activated by pressing one of the Stop-EB button in drive or return station or by
the Stop-EB circuit. The drive will shut down immediately and the lift will be
brought to a standstill mechanically by the emergency brake (a=~-0,3m/s²).
SA5 = Stop-SB+EB:
Activated by the Stop-SB+EB circuit. The drive will shut down immediately and
the lift will be brought to a standstill mechanically by the emergency brake and
the service brake (a=~-0,6m/s²)."

Reminiscent of that joke with the Microsoft-built car: in case of impact, airbags were deployed after the user clicked "OK" in the "Are you sure?" pop-up window.

Bud is right about the interface.

We ended up abandoning the normal stop on the pedestals where the ops use is high, the main panels still have all 4 stops for morning checks.

We ended up abandoning the normal stop on the pedestals where the ops use is high, the main panels still have all 4 stops for morning checks.

Just curious, you got rid of the "normal stop"? Your pedestals have a "service stop"?

I understand the "overwhelming the operator part". Two types of "e-stop" buttons? One performs a true e-stop (drive disengaged and drive sheave brake applied) and the other e-stop is a ramped stop performed by the drive then brakes apply. The true e-stop is for loss of control (unwanted acceleration, overspeed, lift won't stop, etc.) and the ramped is for a smoother controlled stop (derail, decel fault, etc.)

Explain all that to an operator and their eyes get all glassy.

The Service Stop =SA3 buttons are only on the main control panels our pedestals had normal stop= SA1, emergency stop=SA2, emergency shutdown=SA5, speed selection knob, start, reset, (ready at return terminal) and signal buttons

Using the list Razvan provided we ditched the SA1 normal stop in favor of SA2

In the good old days there were no stop buttons, we just wanted the lift to run, then we had a stop button with a sign that said"don't stop the lift!"

Their eyes are glassy when they punch in in the am.

True.

I think at least some of the issue is the different (and competing) design philosophies of the two main manufacturers. One follows the 'more is better' school, to the detriment of exasperated mechanics and electricians everywhere. Don't get me wrong, if safety is a concern, then by all means provide a safety function. Four separate stop buttons that all mean different things to different people, though? Why? Why not provide a 'normal' stop for normal situations such as loading mishaps, and an emergency shutdown for all other aspects?

liftmech, on 17 August 2012 - 06:56 AM, said:

These systems are supposed to be smart. Seems to me that the system should be the arbitrator of the needed stopping procedure. The operator should only need to choose (I intentionally avoided "decide") between NORMAL and EMERGENCY. If there are echelons within these basic categories, then the logic solver should make the appropriate changes regarding brakes, regen strength, stopping distance, etc. to suit the accumulated data.

A button somewhere to actuate each of what might be many stopping scenarios would be nice - for testing purposes only. The operator need not play the multiple choice game, as they have trouble enough picking the right one when there are only two choices.

Hell, why not use a large potentiometer at each control station - kinda' like a volume control - to choose braking intensity. Or maybe even a brake pedal like is in the guy's Toyota? (it now over-rides the gas pedal, you know)

Emax, on 17 August 2012 - 09:07 AM, said:

How about a button that regulates the decelaration based on how hard the button is pushed?

wbl

"How about a button that regulates the deceleration based on how hard the button is pushed?"

... or differentiate between a tap and a slam?

exactly

How about we drill into the op's heads what the 2 buttons are for....... And when each should be used....
This post has been edited by Kicking Horse: 24 August 2012 - 05:32 PM