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greenspun.com : LUSENET : Elevator Problem Discussion : One Thread

Iam an elevator maintenance guy from singapore i got some doubts if any body can help I will appreciate.

1)How to calculate the pit depth distance? 2)How to calculate the main sheave diameter? 3)How to calculate the buffer stroke? 4)How to calculate the speed governor speed trip data? 5)How to calculate the car platform area?

If there is any formula please let me know thanks

-- Lakshmanan Raja (rajas73@hotmail.com), June 25, 2004

Well there is no such calculation but you can refer to BS5655 part 5 where you can find the arrangements for lifts starting from 400Kg 0.5m/s up to 5000Kg 0.63 m/s including arrangements for 3.5m/s.

the selection of appropriate lift speed for a given lift travel is usually based on general experience rather than precise traffic calculations, except for the most elaborate installations.

I may give you layout for general purpose passengers lift installations for 630 Kg 8 person lift: Car internal size: Width 1100mm, Depth 1400mm, height 2200mm, Well min dimension: Width 1800, depth 2100mm Car entrance: width 800mm, height 2000mm clear entrance: width 800mm, height 2000mm Pit depth: 1700mm headroom:(from top level) 4000mm for 1.00m/s 4200mm for 1.6m/s Machine room: area 15 square meters width 2500mm depth 3700mm height 2600mm unless you are using MRL good luck

-- (mo_is2@hotmail.com), June 26, 2004.

Energy accumulation-type buffers has to have the total stopping distance of the buffers to be at least equal to twice the gravity stopping distance corresponding to 115% of the rated speed with minimum of 65mm and for this stroke to be covered by a static load of between 2.5 and 4 times the mass of the car (car and rated load).

the quick way to check for traction sheave Diameter of Traction sheave/diameter of rope=40/1 i.e for 13mm cable Diameter of sheave should be at least 520mm.

speed trip data is made by the manufacturer of the speed governor and normally limited to 115% of nominal speed.

-- (mo_is2@hotmail.com), June 26, 2004.

Thanks a lot mo_is2@hotmail.com, now iam clear about the speed governor trip and sheave diameter.

The buffer stroke calculation I am not able to understand. How to find the gravity stopping distance? Could you please explain me again with an example?

Once again thanks for the immediate help.

-- raja (rajas73@hotmail.com), June 26, 2004.

(for specified speed V) the gravity stopping distance equals to=Vsquare divided /2x9.81.

so buffer stroke (or stopping distance) is required by law for a full loaded car travelling at 115% of rated speed to be at least twice the gravity stopping distance: buffer stroke =2X(VX115)(VX115)/(2X9.81)=0.135XVsquare.

for 1m/s car the stopping distance is 0.135m when buying any buffer all the data is calculated by the manufacturer so you do not have to worry about unless you are using a normal spring which's not allowed. I hope this is ok.

-- (mo_is2@hotmail.com), June 28, 2004.

Thanks a lot for the help.I got it now.

-- raja (rajas73@hotmail.com), June 28, 2004.

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