20 replies to this topic

[skierdude9450]

In North America, as I take it, our evacuation motors are simply auxillary generators that produce electricity to power the main engine. However, what if the main drive was to fail? Is it possible to operate the lift at all in that case? After studying some European back-up systems, they have a diesel motor connected to a gearbox which powers the lift completely independent of the main drive (although at a maximum speed of 1.5 m/s). So I was wondering can we operate our lifts at all if the main drives fail?

[mikest2]

skierdude9450, on Oct 7 2008, 09:16 AM, said:

In North America, as I take it, our evacuation motors are simply auxillary generators that produce electricity to power the main engine. However, what if the main drive was to fail? Is it possible to operate the lift at all in that case? After studying some European back-up systems, they have a diesel motor connected to a gearbox which powers the lift completely independent of the main drive (although at a maximum speed of 1.5 m/s). So I was wondering can we operate our lifts at all if the main drives fail?

On our big lifts we run a main drive electric, an auxiliary (80-100%) diesel drive, and an evacuation diesel drive(1.5 m/s).This way if the power goes out or the main drive fails, we can still operate as we still have an evacuation drive. Some areas will run on their aux diesel at peak times to reduce their electrical utility peak demand charges.

[Lift Dinosaur]

Actually, Dude, that's sort of backwards.
In Europe, many resorts use diesel powered generators ("gen sets") to generate their own electricity in the event of a power outage. They may have a small diesel evacuation engine to run the lift at @1.5m/s in the event of an electric drive failure.
In North America, lifts are required to have at least power units (ANSI 3.1.2.1) one of which is an Auxiliary Power Unit (APU) with an independent power source - that means you can't have a second electric motor as a backup to you primary electric motor.
What you generally see in N.A. is:
Primary mover = electric motor (there are lifts that utilize diesel prime movers)
APU - this can be either full use (80-100% speed) and utilize the same controls as the primary mover; OR an evacuation APU which only is required to run the lift at 100FPM (.51 m/s) These units are generally diesel engines, while some older or smaller fixed grips utilized gasoline engines.

Hope this helps...

Dino

P.S. Ya got in there ahead of me Mike!!

This post has been edited by Lift Dinosaur: 07 October 2008 - 09:18 AM

[poloxskier]

skierdude9450, on Oct 7 2008, 07:16 AM, said:

In North America, as I take it, our evacuation motors are simply auxillary generators that produce electricity to power the main engine. However, what if the main drive was to fail? Is it possible to operate the lift at all in that case? After studying some European back-up systems, they have a diesel motor connected to a gearbox which powers the lift completely independent of the main drive (although at a maximum speed of 1.5 m/s). So I was wondering can we operate our lifts at all if the main drives fail?

I don't know if the new system will have an evac motor but the former River Run Gondola had the main electric drive, Diesel APU, and a Hydrostatic evac motor that acted directly on the teeth on the bullwheel so that it was not reliant on the gearbox or the rest of the drive line to provide power. I do not know the speed it would run it at but I would assume that it would be around the 1.5m/s mark.

The majority of aerial lifts, and some surface, in colorado, at least that I am familiar with, have a near full service APU more for the convenience of guests than anything, so that if power is lost the resort can continue to operate at close to full capacity.

This post has been edited by poloxskier: 07 October 2008 - 10:26 AM

[Lift Kid]

poloxskier, on Oct 7 2008, 01:23 PM, said:

I don't know if the new system will have an evac motor but the former River Run Gondola had the main electric drive, Diesel APU, and a Hydrostatic evac motor that acted directly on the teeth on the bullwheel so that it was not reliant on the gearbox or the rest of the drive line to provide power. I do not know the speed it would run it at but I would assume that it would be around the 1.5m/s mark.

I believe Aspen has something similar.

On the American Eagle at Copper, the diesel engine couples to the gearbox. On the Eagle Bahn at Vail, there are two diesel generators and two electric drive motors. I do not believe there is another engine that couples to the gearbox. Anybody know if that lift has another evac system? Maybe hydro?

[Lift Dinosaur]

poloxskier, on Oct 7 2008, 12:23 PM, said:

... and a Hydrostatic evac motor that acted directly on the teeth on the bullwheel so that it was not reliant on the gearbox or the rest of the drive line to provide power...

This is known as a Tertiary or "third" drive system. It is often a hydrostatic motor with a pinon gear that runs on a ring gear inside the bullwheel. For this to work, you need a fast disconnect coupling to disengage the bullwheel from the gearbox.
I'll look for some photos...

Dino

P.S Post 3 should have said "have at least TWO power units..."

[skierdude9450]

Okay that makes sense now. So are you saying that the majority of APUs are indeed not diesel-electric generators?

[aug]

At Schweitzer we have a 4CLD which was a Yan and is now a DoppleYan. This lift has a unique APU system. The Main electric motor and dc drive (Drive "A") and a second aux electric motor and seperate dc drive sized for that motor(Drive"B") 60% of speed . In a nearby vault there is a diesel genset to run either drive in the event of a power outage. I am not impressed with this system.

[Lift Dinosaur]

skierdude9450, on Oct 7 2008, 06:37 PM, said:

Okay that makes sense now. So are you saying that the majority of APUs are indeed not diesel-electric generators?

Correct. Most are diesel engines that are shaft coupled thru the gearbox to run the lift.

For some reason, even though diesel fuel is STILL cheaper here than in Europe, N.A. Resorts haven't grasped the concept of still providing "full service" during a power outage. You can ride the lifts, but you can buy food or drink because the credit card readers and cash registers aren't working (sept for the Mom and Pop areas where it doesn't require electricity to open the Cigar Box!!)

Dino

[lift_electrical]

aug, on Oct 7 2008, 05:41 PM, said:

At Schweitzer we have a 4CLD which was a Yan and is now a DoppleYan. This lift has a unique APU system. The Main electric motor and dc drive (Drive "A") and a second aux electric motor and seperate dc drive sized for that motor(Drive"B") 60% of speed . In a nearby vault there is a diesel genset to run either drive in the event of a power outage. I am not impressed with this system.

Aug,

Was this the APU arrangement before the lift was modified?

[aug]

lift_electrical, on Oct 7 2008, 08:50 PM, said:

Aug,

Was this the APU arrangement before the lift was modified?

yes Yan original Equipment... vertical drive electric motors to a planetary hollowshaft gearbox. The aux. elec motor sits adjacent to the main and is coupled with a fibre cog belt to the input shaft of the gearbox.

[Kicking Horse]

I know that the lifts that I was the Drive op on the Diesel ran the lift at 788fpm were on the elec the speed was around 985fpm. (At Beaver Creek)

Then they also had a 3rd motor that I dont know anything about.

[aug]

Kicking Horse, on Oct 7 2008, 09:12 PM, said:

I know that the lifts that I was the Drive op on the Diesel ran the lift at 788fpm were on the elec the speed was around 985fpm. (At Beaver Creek)

Then they also had a 3rd motor that I dont know anything about.

The third one most likely is the hydraulic aux.power unit.( for evac only). The big diesel is the Standby engine( normaly ok to run and load with)

[SuperRat]

Does anyone have a lift that uses a groomer to power the tertiary drive? If so, do you have a groomer that can be wired into the lifts 24 volt safeties?

[lift_electrical]

aug, on Oct 7 2008, 08:58 PM, said:

yes Yan original Equipment... vertical drive electric motors to a planetary hollowshaft gearbox. The aux. elec motor sits adjacent to the main and is coupled with a fibre cog belt to the input shaft of the gearbox.

Yea, the Yans I was around had a Aux. diesal that drove a hydrastatic motor that drove the cog belt. The belt was very touchy as far as alignment. Also, we were not allowed in the motor room while this setup was running due to an incident (where?) to a maintenance person getting hurt when the hydrastatic motor blew up on him. Hard to watch the belt and everything else from outside the motor room. The worst part was having the aux. motor adjacent to the operator shack. Hard to get a nap in while the motor was blasting at 2000 rpm

[Aussierob]

SuperRat, on Oct 8 2008, 12:15 AM, said:

Does anyone have a lift that uses a groomer to power the tertiary drive? If so, do you have a groomer that can be wired into the lifts 24 volt safeties?

We don't, but it would be possible to do. Not sure of the technicalities of the lift codes though. They may specfically require the evac drive to be part of the lift. As for the 24v system, the alternator on the diesel engine provides the 24v at the drive and an alternator driven off the lift provides power at the return. If you were using the snowcat method, you would need a 24v supply if the batteries in the lift didn't have enough power to run the lift until the line was cleared.

[SuperRat]

Aussierob, on Oct 9 2008, 11:24 AM, said:

We don't, but it would be possible to do. Not sure of the technicalities of the lift codes though. They may specfically require the evac drive to be part of the lift. As for the 24v system, the alternator on the diesel engine provides the 24v at the drive and an alternator driven off the lift provides power at the return. If you were using the snowcat method, you would need a 24v supply if the batteries in the lift didn't have enough power to run the lift until the line was cleared.

I worked briefly at an area with a CTEC detachable that had a tertiary drive that was powered by the hydraulic pump of a cat. There was even a special hole in the terminal enclosure for routing the hydraulic lines. I never got the chance to see the system in operation. There was also a question about whether any of the area groomers were wired to be connected to the lift's controls which was required by the local tram board.

[lift_electrical]

Big Sky's tram is set up to run a tertiary with a cat. Not sure if they use it though.

[barnstormer]

SuperRat, on Oct 8 2008, 03:15 AM, said:

Does anyone have a lift that uses a groomer to power the tertiary drive? If so, do you have a groomer that can be wired into the lifts 24 volt safeties?

At Deer Valley, a number of the older Yan's were set up with a snowcat drive tertiary which we did test occasionally. I believe Northside, a 1993 CTEC detach, also had a snowcat tertiary. As far as electrical connections go, hopefully the lift's control system batteries would be enough to run the safeties for as long as it took to run the people off. The only other required connection would be two wires to close the cat's fuel solenoid when a stop is issued. That's all that runs to most non-fulltime APU's.

[liftmech]

At Crystal our one detach (Rex) had a tertiary motor which was run by an old LMC groomer. The tiller had been removed and the tiller controls ran the evac motor. I don't recall if the cat was wired into the lift or not- I don't think it was though. The hydrostatic motor was coupled to the lift via the splitter box in the front of the gearbox, opposite the input for the full-service aux engine.