BDCS 7 (vertical transportation)

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  1. hydraulic elevators
    • lifted by plunger, or ram, set in the ground directly under the car and operated with oil as the pressure fluid
    • used for passenger and freight for 2 to 6 story buildings or about 50ft
    • 2000lbm to 20,000lbm
  2. electric elevators
    • cab suspended by cables (known as ropes) that are draped over a sheave and attached to a counter-weight
    • aka traction elevators
    • travel from 250fpm to 1800fpm
    • 2,000lbm to 5,000lbm
    • types: 1)gearless traction elevators 2)geared traction elevators
  3. gearless traction elevators
    • type of electric elevator
    • use a direct current (DC) motor directly connected to the sheave
  4. geared traction elevator
    • type of electric elevator
    • used for slow speeds from 25fpm to 450fpm
    • high speed DC or AC motor drives a worm gear reduction assembly to provide a slow sheave speed
  5. roping
    refers to arrangement of cables supporting the elevator
  6. single wrap
    • simplest type of roping
    • rope passes over the sheave only once and is then connected to the counterweight
  7. double wrap
    • for high-speed elevators, when additional traction is required
    • disadvantage of double wrapping is that there are more bends in the cable and consequently a shorter rope life
  8. selective collective operation
    • most common type of system
    • elevator remembers and answers all calls in oen direction and then reverses and answers all calls in opposite direction
  9. governer
    senses the speed of the car and if is exceeded, the brake is applied
  10. safety rail clamp
    grips the side rails if there is an emergency
  11. safety edges
    movable strips on the leading edge of the door that activates a switch to reopen the door if something contacts it
  12. height of car controls
    • max 54" for side approaches
    • max 48" for front approach
  13. interval or average waiting time
    • diversified offices between 30 to 35 sec
    • hotels and apartments from 40 to 70 sec or more
  14. elevator code classes
    • A
    • B
    • C1
    • C2
    • C3
  15. class A elevator
    • general freight and no item can exceed 1/4 of the rated capacity of the elevator
    • rating cannot be less than 50lbm/sf of platform area
  16. class B elevators
    used for motor vehicle loading and are rated at no less than 30lbm/sf
  17. class C elevators
    industrial truck loading based on 50lbm/sf
  18. class C1 elevators
    includes the truck
  19. class C2 elevators
    does not include the truck
  20. class C3 elevators
    concentrated loading with the truck not carried and with increments greater than 25% rated capacity
  21. min width of stair
    • 36"
    • 44" with occ more than 50
  22. max distance between landings
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BDCS 7 (vertical transportation)
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