Lifts
Lift is an appliance designed to transport persons or materials between two or more levels in a
vertical or substantially vertical direction by means of a guided car.
Dumb waiter lifts, moves in guess in a vertical direction, has net floor area not exceeding 1m2.
To inside height of 1.2m. has a capacity not exceeding 250kg. Used for carrying materials only
and not people.
Lift pit-
The space in the lift well below the level of the lowest lift landing served.
Lift landing-
Portion of building or structure used for discharge of passengers it goods or both into or from a
lift car.
Rated load-
The maximum load for which the lift car is designed and installed to carry at rated speed
Rated speed-
The mean of the maximum speed attained by the lift car in the upward and downward direction
with rated load in the lift car.
MRL Lift-
Machine room less lift, it does not have a fixed machine room, on top of the hoistway, instead,
the traction hoisting machine, is installed either on the top side wall of the hoistway or on its
bottom.
Consideration for selection of lift-
Intended use of lift-
The number of lifts and their capacities (that is list and speed) required for given building shall
be suitably decided to meet intended requirement
System performance-
Based on building type (residential, commercial, etc)
Accessibility-
Public use lifts should meet requirements in accordance with, 13 part 3 development control
rules and general building requirements
Environmental conditions-
Lifts exposed to atmospheric conditions, weathers or any other adverse condition shall be
appropriately designed and protected for that particular condition.
Type of main drive of lift-
Whether electric traction, geared or gear less, or hydraulic depending on speed, height, capacity
Civil engineering requirements-
Machinery location, that is, machinery to be located in machine room or machinery to be kept
inside lift well thereby eliminating conventional machine room.
Seismic considerations-
Whether the lift is to be protected against seismic forces or whether the lift is to be rescued to a
landing on detection of earthquake or both.
Types of lifts-
Traction (electrical) lift-
-virtually limitless rise
-high speeds, but high installation cost
Hydraulic lift-
-limited to heights of about 60ft
-lower speeds
-lower initial cost-higher power consumption
-in case pressure in lift is released, the lift will be in free fall.
-supported by a piston at the bottom of the elevator that pushes the elevator up as an electric
motor forces oil or another hydraulic fluid into piston
-have a maximum speed of 200 feet per minute.
Gearless traction lift-
Have wheel attatched directly to the motor.
Capable of speeds up to 2000 ft. Per minute and they have a maximum travel distance of sound
2000 feet, so they are the natural choice fir High rise buildings.
Geared traction elevators are middle of the road in terms of initial cost, ongoing maintenance
cost. Gearless have high initial cost.
