can u tell me what are the advantages and disadvantages of using a machine roomless type of elevator with permanent magnet control system? also please indicate the maximum speed you can reach for that type of elevator?

-- john sylvestus (john_sylvestus@yahoo.com), October 29, 2003

Answers

Some advantages are that no machine room is required and certain of the loads are transferred to the earth instead of imposing them upon the building structure. They are reportedly less costly than conventional traction elevators for comparable applications.

Permanent magnet machines have advantages and disadvantages irrespective whether they are used in a machine room less (MRL) arrangement or not.

The usual speed of such MRL's as I know about is 200 fpm. For the typical rise for which they are commonly used, that is sufficient.

Most present day designs are restricted as to capacity.

In many jurisdictions in the U.S., MRL arrangements do not comply with prevailing codes.

-- John Brannon (akaelevman@aol.com), October 29, 2003.

ARCHITECT: The Machine room less design is a great for architects because they dont need an big house built on top of a building over each elevator shaft. Also they dont need to design in the larger structural steel beams support, access to mr, ect ect. In most states there is no machine room at all because the controls are in the return jamb. Calif must have a seperate room inside the bldg next to the hoistway.

CONSTRUCTION: The machine room less design is great for general contractor because the installation cost and time is down and you can get rid of the outside hoist sooner and use the elevator for construction purpose.

OWNER: The machine room less design is great for him because he has a very efficent elevator power wise and if he chooses Kone he has a very reliable elevator.

CHOICES: there are so many machine room less elevator designs with the machine being installed every where, I have even seen the hoist machine being built into the crosshead above the cab in China. Allways choose the company with the most experiance installing these with thousands installed all over the world choose KONE.

-- Jim (elevator555@hotmail.com), October 30, 2003.

Machineroomless elevator.

I haven't had any experience with a machineroomless elevator, so please bear with me. Just as a question, how do you fix the stuff safely if there isn't a machine room? Especially should the not be access to the jambs ( occupied)? Since we live in earthquake country, what kind of access do you have to the equipment to make inspections and repairs? Do they require you to have rapelling gear to get the weights back in the rails (or weights back in the frames as we found out in Northridge-94 Thank God they used thru-bolts on the weights, otherwise we might have had the weights sitting in the cab), or climbing gear to check out the machine for shifting or damage? Speaking of weights, does anyone still use rods in their weights, or did they present calc's about weight frame strength? It'll be fascinating when the next large EQ rolls through here. Cheers!

-- Steve (magnevator@verizon.net), October 31, 2003.

On Otis's GEN2 every floor has access as per the australian lift code also has a feature which has a battery backup for the brake and if at anytime there is a power failure or drive going down etc you can turn the key and push the brake release button and the lift will "jog" to the next floor up and stop when it gets to the door zone.

-- dayle (daylebrenda@iprimus.com.au), October 31, 2003.

For the description of MRL, u can chk out the elevator-world.com n in that the issue of April-2003 which desceibes the basic funtion, the power consumption n the resue mechanism in MRL. Its bascially abt one company product but its also a general article. so good to read! Hope this clears all the doubts regarding the power consumption. \ Basically for lifting a particular load, u hav to use a minimum power. so if the elevator is 630 with machinroom or w/o the efficency n hence the power consumption will be also same if u adapt the same machine to be used in machine-room elevator or machineroom less elevator.

Rahul

-- rahul singh (rah@softhome.net), June 06, 2004.