Advanced services

2.  Lift- 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. The word ‘
elevator’is also synonymously used for lift.
 TYPES of lifts- DRIVE SYSTEM
Hydraulic Traction (Machine lift)
Hydraulic Elevators: • Pumps provide oil pressure for lift. An electric motor pumps the oil into a cylinder to move
the piston • They are used in low rise buildings up to 50 feet high or 5 stories maximum. • Speeds vary from 25 to 150
fpm (Feet Per Minute)
Hydraulic Elevator Types
• In-Ground: This type has a cylinder that extends into the ground the same height to which the elevator is to be
lifted.
• Hole-Less: This type uses telescoping pistons on one or both sides of the cab to lift it. The cylinder stands within the
hoist way and does not require a drilled hole. This class is typically limited to under 40’ of travel.
• Roped: This type is similar to a traction type elevator. The cab is elevated by an attached rope that is pulled by
pistons.
No wires, cables, or overhead machinery is required for the In-Ground and Hole-less types. A machine room is
required to house both the oil storage tank and the pump. The slow speeds of hydraulic elevators makes the ideal for
freight elevators up to 50 tons.

3. Pros and Cons-
 The main advantage of hydraulic systems is they can easily multiply the relatively weak force of the pump to
generate the stronger force needed to lift the elevator car.
 But these systems suffer from two major disadvantages.
 The main problem is the size of the equipment. In order for the elevator car to be able to reach higher floors, you
have to make the piston longer. The cylinder has to be a little bit longer than the piston, of course, since the
piston needs to be able to collapse all the way when the car is at the bottom floor.
 In short, more stories means a longer cylinder. The problem is that the entire cylinder structure must be buried
below the bottom elevator stop. This means you have to dig deeper as you build higher.
 This is an expensive project with buildings over a few stories tall. To install a hydraulic elevator in a 10 -story
building, for example, you would need to dig at least nine stories deep!
 The other disadvantage of hydraulic elevators is that they’re fairly inefficient. It takes a lot of energy to raise an
elevator car several stories, and in a standard hydraulic elevator, there is no way to store this energy. The energy
of position (potential energy) only works to push the fluid back into the reservoir. To raise the elevator car again,
the hydraulic system has to generate the energy all over again.

5. Traction Elevators (Pull Elevators).
 The Most Common type of Elevators. Cars pulled up by means of rolling steel ropes over a deeply grooved
pulley, commonly called a sheave.
 The weight of car balanced by a counter weight. Sometimes cars built in pairs and synchronized to move in
opposite directions, and serve as each other’s counterweigh.
 Traction elevators use steel cords or flat steel ropes a lot of traction elevators prefer the use of flat steel ropes
because they are extremely light due to its carbon fiber core and a high-friction coating, and does not require any
oil or lubricant. Because of these qualities, elevator energy consumption in high-rise buildings can be cut
significantly.
Different types of Traction Elevators
Geared Traction Elevator-
 The Gear Box Is attached to the Motor, to drive the wheel and pull the rope.
 These elevators typically operate at speeds from 38 to 152 meters (125500 ft) per minute and carry loads of up to
13, 600 kilograms (30, 000 lb).Machines Driven by AC or DC electric motors hoists.
 Geared machines use worm gears to control mechanical movement of elevator cars by "rolling" steel hoist ropes
over a drive sheave which is attached to a gearbox driven by a high speed motor.
 An electrically controlled brake between the motor and the reduction unit stops the elevator, holding the car at
the desired floor level.

6. Gearless Traction Elevator-
 There is a wheel attached to the motor. These elevators typically operate at speeds greater than 500 feet per
minute.
 A brake is mounted between the motor and drive sheave (or gearbox) to hold the elevator stationary at a floor.
Gearless Overhead-
 Gearless traction elevators are also used in high speed applications for tall hoist ways however they are typically
used for shorter hoist ways and lower speeds than their 1: 1 cousins. Like the 1: 1 machine the 2: 1 gearless
elevator consists of a traction sheave, brake drum and motor armature or rotor all mounted on a common shaft
supported by two roller bearings.
 The main difference is the roping configuration which allows for a motor rotational speed that is double that
employed in the 1: 1 machine for the same car speed (and hence the use of smaller motor frames for the same
horsepower).
 The gearless motor can be either A-C or D-C. They can be single or double wrapped

7. Traction Elevators Disadvantages:
 Installation costs can be 15 -25% higher than the hydraulic elevators. Traction elevators might be initially offered
at a low and convenient price and then skyrocketed with outrages service charges.
 Maintenance is difficult because the machine is located in the headroom of the shaft and reaching it can be a
challenge. Serious accidents during construction and servicing of the elevator are highly probable. If the car is
stuck, the machine cannot be serviced from the top of the car, and insecure methods may then be needed.
 Traction elevators are initially offered at reasonable prices and the low income is later attained through frequent
servicing and high-priced spare parts. Obtaining the spare parts can be a nightmare since servicing may only be
performed by the original installer or by their service partners.
Traction Elevators Advantages:
 It uses less energy than hydraulic elevators because the motor is only used to overcome friction - there is no
lifting involved because of the counterweight system. The only time the motor is used in traction elevators to lift
the cab is when the counterweight is not even with the cab weight.
 The most inefficient of these elevators are older models that use direct current electricity - used because it is easy
to control speed with DC current.
 Most of the energy used by these elevators happens when it is idle from the heating, cooling and lighting
systems. Using LED lighting and timers for fans will help reduce the energy use.
 To put the energy use in relative terms, the energy used in light sensor stairways exceeds that of the energy used
for a traction elevator ride.

9.  TYPES of lift- USAGE
Passenger Goods Vehicle Dumbwaiter Scissor
Passenger Lift : A lift designed for the transport of passengers.
• Goods Lift : A lift designed primarily for the transport of goods but which may carry a lift attendant or other person
necessary for the unloading and loading of goods.
 Hospital
 Hotel
 Residential
 Office
 Institution
 Goods/Freight lifts •Used to transport heavy goods but depends on types of good transported. • Usually used in
shopping complex, airports, hotels, warehouse.
 Vehicle lifts •Used specifically to lift a car in multi storey car park or showroom. •had to be in the form of traction and
hydraulics. •Form of traction is more commonly used for high velocity.
 Dumbwaiter lifts •Dumbwaiters are small freight elevators that are intended to carry food rather than passengers.
•They often link kitchens with other rooms. •When installed in restaurants, schools, kindergartens, hospitals,
retirement homes or in private homes, the lifts generally terminate in a kitchen. •Avg height of the car ranges from
0.8m to 1.2m, these lifts are self-contained, these lifts can be easily moved to where they are needed.
 Scissor lifts •they’re excellent for indoor and outdoor construction, maintenance and installation applications.
Features: High load bearing capacity Long life Smooth operations.

10.  Considerations for Selection of Lifts
The considerations for selection of lifts shall be based on the following criteria:
a) Intended use of lift.
b) System performance
c) Accessibility requirements
d) Environmental conditions
e) Type of main drive for lift
g) Seismic considerations
 Maintenance
The considerations relating to maintenance shall be as follows:
a) The lift installation shall receive regular cleaning, lubrication, adjustment and adequate servicing by authorized
competent persons at such intervals as per type of equipment and frequency of service demand.
b) In order that the lift installation is maintained at all times in a safe condition, a proper maintenance schedule shall be
drawn up in consultation with the lift manufacturer and rigidly followed. The provision of a log book to record all items
relating to general servicing and inspection is recommended for all lifts.
c) Any accident arising out of operation or maintenance of the lifts shall be duly reported to the authority in accordance
with the rules laid down.
d)The company entrusted with maintenance contract shall have valid license to maintain the lifts. The persons assigned
for maintenance work shall be appropriately qualified and experienced as required by Lift Acts and Rules

11.  Energy Efficiency and Sustainability
Design options like space restrictions, reliability and safety, riding comfort have been the major market and
technological driver. The following should be encouraged for reducing power consumption and promoting
sustainability in buildings.
a) Energy efficient a.c. variable voltage variable frequency (VVVF) motor drive or equivalent. Lifts with 1-speed
and 2-speed motor control are not recommended for passenger lifts because of high power consumption, poor
passenger comfort and tripping hazard.
b) When the lift has answered the last call and stopped at a landing and no further landing call is registered, the car
and landing doors shall close. If there is no further landing call after pre-determined period but not less than 90 s,
the light and fan inside the car shall both be automatically switched off. Car lights and fan shall switch on
automatically before the lift doors start to open or the lift is set in motion.
c) Under normal operating status, at least one lift car of a lift bank shall operate under a standby or sleep mode
during off-peak period when the traffic demand on the vertical transportation system is low. During low demand
periods, even completely shutting down one or more lifts within a group can be a good energy saving option,
without compromising quality of service.
d) Where a number of lifts are installed together, their controls are interconnected to optimize their operation. By
efficiently delivering passengers with the least amount of trips, starts and stops, the energy consumed is
significantly reduced.
e) Energy saving LED lamps for car lighting in place of conventional lamps.
f) Gearless type machines to reduce transmission losses.

12. g) Improvement in total power factor of the motor drive of a lift at the isolator connecting lift to the buildings
electrical supply circuit.
h) Regenerative drives to recycle energy rather than wasting it as heat. The regenerated energy may be used for
charging batteries, staircase lighting, lobby lighting, etc. j) Use of high efficiency motors such as Permanent Magnet
Synchronous Motors, or Induction motors having minimum efficiency class equivalent to IE2 as per accepted
standard.
k) Adoption of materials and practices that are environmentally friendly and sustainable shall be promoted.
 PLANNING AND DESIGN GUIDELINES
Two basic considerations, namely, the quantity of service required and the quality of service desired, determine the
number and type of lifts to be provided in a particular building. The quantity of service factor, that is, how many
people might use the lift system over a defined period of time is represented by the handling capacity. The quality of
service factor, that is, how well the lift system deals with its passengers is represented by passenger waiting time and
lobby queuing. These factors are interrelated and depend, among other things, on the type of building and its use and
on the type of occupier. Both these factors require proper study into the character of the building, extent and duration
of peak periods, frequency of service required, type and method of control, type of landing doors, etc.
The architect/engineer doing the planning work should establish the lift system at a very early stage in consultation
with the lift manufacturer/ consulting engineer and not after the rest of the building has been designed.

14. GENERAL TERMS RELATING TO LIFTS-
 Automatic Rescue Device ARD- Elevator emergency automatic rescue device (also
known as ARD) is a special device installed in an elevator which is only used during
an event of a power failure or blackout in a building.
 Buffer- A device designed to stop a descending car or counter weight beyond its normal
limit of travel by storing or by absorbing and dissipating the kinetic energy of the car or
counterweight.
 Oil buffer- A buffer using oil as a medium which absorbs and dissipates the kinetic
energy of the descending car or counterweight.
 Oil buffer stroke- The oil displacing movement of the buffer plunger or piston,
excluding the travel of the buffer plunger accelerating device.

15.  Spring buffer- A buffer which stores in a spring the kinetic energy of the descending car or
counterweight.
 Call Indicator- A visual and audible device in the car to indicate to the attendant the lift
landings from which calls have been made.
 Slack Rope Switch- Switch provided to open the control circuit in case of slackening of
rope(s).
 Suspension Ropes- The ropes by which the car and counter weight are suspended.
 Total Headroom- The vertical distance from the level of the top lift landing to the bottom of the
machine room slab.

16.  Elevator car : That part of an elevator that includes the platform, enclosure, car frame, and door.
 Machine beam : A steel beam, positioned directly over the elevator in the machine room and is
used to support elevator equipment.
 Machine room : This usually located at the top of the shaft and accommodates the winding
machine, etc.
 Pit : That part of an elevator shaft that extends from the threshold level of the lowest landing
door down to the floor at the very bottom of the shaft.
 Shaft : A hoist way through which one or more elevator cars may travel.
 Counterweight or balance-weight. A unit, consisting of steel weights, which counter balance the
weight of the car and a portion of the load, and to which the suspension ropes are attached.
 Traction drive : Lift whose lifting ropes are driven by friction in the grooves of the driving
sheave of the machine.
 Trailing cable : Flexible cable providing electrical connection between the lift car and a fixed
point or points.
 Bottom clearance : The distance, including buffer compression, the platforms could travel below
the bottom landing until the full weight of the car, when loaded, rests on the buffer.
 Top clearance :The vertical distance between the top car attachment and the bottom of the
diverting pulley or any steelwork supporting equipment; there must be an adequate margin
between this and the car will not contact the diverting pulley or steelwork.

17.  Guide rails- These, fixed truly vertical in the shaft, are of steel and serve to guide the movement of both car and
counterweight.
 Car Frame- The supporting frame or sling to which the platform of the lift car, its safety gear, guide shoes and
suspension ropes are attached.
 Car Platform- The part of the lift car which forms the floor and directly supports the load.
 Control- The system governing starting, stopping, direction of motion, acceleration, speed and retardation of moving
member.
 Deflector Sheave- An idler pulley used to change the direction of a rope lead.
 Door, centre opening sliding- A door which slides horizontally and consists of two or more panels which open from the
centre and are usually so interconnected that they move simultaneously.
 Door, mid-bar collapsible- A collapsible door with vertical bars mounted between the normal vertical members.
 Door, multi-panel- A door arrangement whereby more than one panel is used such that the panels are connected together
and can slide over one another by which means the clear opening can be maximized for a given shaft width. Multipanels
are used in centre opening and two speed sliding doors.
 Door, single slide- single panel door which slides horizontally.
 Door, two speed sliding- A door which slides horizontally and consists of two or more panels, one of which moves at
twice the speed of the other.

18.  Door, vertical bi-parting- A door which slides vertically and consists of two panels or sets of panels that move
away from each other to open and are so interconnected that they move simultaneously.
 Door, vertical lifting- A single panel door, which slides in the same plane vertically up to open.
 Door, swing- A swinging type single panel door which is opened manually and closed by means of a door closer
when released.
 Door Closer- A device which automatically closes a manually opened door.
 Door Operator- A power-operated device for opening and closing doors.
 Guide Shoe- An attachment to the car frame or counterweight for the purpose of guiding the lift car or counter
weight frame.
 Hoisting Beam- A beam, mounted immediately below the machine room ceiling/machinery space ceiling, to
which lifting tackle can be fixed for raising or lowering parts of the lift machine.
 Landing Call Push- A push button fitted at a lift landing, either for calling the lift car, or for actuating the call
indicator.
 Landing Door- The hinged or sliding portion of a lift well enclosure, controlling access to a lift car at a lift
landing.
 Landing Zone- A space extending from a horizontal plane 400 mm below a landing level to a plane 400 mm
above the landing level
 Levelling device, lift car- Any mechanism which either automatically or under the control of the operator, moves
the car within the levelling zone towards the landing only, and automatically stops it at the landing

19.  Lift Car- The load carrying unit with its floor or platform, enclosing bodywork, and car door.
 Lift Landing- That portion of a building or structure used for discharge of passengers or goods or both into or
from a lift car.
 Lift Machine- The part of the lift equipment comprising the motor and the control gear therewith, reduction gear
(if any), brake(s) and winding drum or sheave, by which the lift car is raised or lowered.
 Lift Pit- The space in the lift well below the level of the lowest lift landing served.
 Lift Well- The unobstructed space within an enclosure provided for the vertical movement of the lift car(s) and
any counterweight(s), including the lift pit and the space for top clearance.
 Lift Well Enclosure- Any structure which separates the lift well from its surroundings.
 Overhead Beams- The members, usually of steel, which immediately support the lift equipment at the top of the
lift well.
 Retiring Cam- A device which prevents the landing doors from being unlocked by the lift car unless it stops at a
landing.
 Safety Gear- A mechanical device attached to the lift car or counterweight or both, designed to stop and to hold
the car or counterweight to the guides in the event of free fall, or, if governor operated, of overspeed in the
descending direction. Any anticipated impact force shall be added in the general drawing or layout drawing
 Sheave- A rope wheel, the rim of which is grooved to receive the suspension ropes but to which the ropes are not
rigidly attached and by means of which power is transmitted from the lift machine to the suspension ropes

20. GENERAL ELEVATOR PLANNING
 Several factors combine to influence the cost of an elevator installation, including the passenger handling capacity, waiting
interval, speed, location, finishes, intelligent group control safety, and reliability. There are also risks associated with the use of
elevators.
 To ensure that persons are not stuck in elevators for longer periods of time, or worse that the elevator does not loose stability and
plummet to the basement from a high floor, the engineers responsible for designing elevators must comply with all statutory codes
and standards.
 Typical parameters in design of elevators include:
Characteristic of the premises
 Type and use of building;
 Floor plate size and height of the building;
 Size of population and its distribution in the premises;
 Fire safety and regulations;
 The house keeping of the premises. Circulation Efficiency
 Number of cars and their capacity;
 Location and configuration of elevators in entrance lobby;
 Travel length, number of stops and maximum acceptable waiting time;
 Arrangement with the combination of elevator, escalator and emergency stairs.

21. Characteristic of the equipment
 Type of transportation systems;
 Rated load and car dimensions
 The speed of the lift/escalator system;
 The type of motor drive control system of the machine;
 Mode of group supervisory control and safety features;
 Cab enclosure and hoist way door finishes;
 Emergency power supplies and fire protection systems;
 Requirements of the local regulations on vertical transport system.
DESIGN ELEMENTS OF ELEVATOR SYSTEMS
 Traffic Planning
 Handling Capacity
 Interval:
 Round Trip Time
 Average Waiting Time
 Elevator Capacity
 Elevator Car Foot Print Area
 Number of Elevators
 Speed of Elevators
 Zoning of Elevators
 Location of Elevators
 Elevator Doors

22. TRAFFIC PLANNING-
 Traffic Planning Elevators’planning in building projects is dependant on the “traffic analysis” study
which varies according to the type and usage of the building. For example, an office building typically
requires more elevators than an apartment building due to heavier loads & traffic. Elevator professionals
often use building type to assist in recommending solutions based on different types of building traffic.
 Traffic analysis is the study of the population distribution and their predicted pattern of flow within the
day. It helps in selecting:
 The correct number and type of transportation devices;
 The right sizes and speeds of the transportation devices;
 The proper control systems and features to optimize and synchronize traffic flow;
 The optimum layout for the transportation devices and correct positioning in the building and in relation
to one another;
 Easy access to buildings and a smooth flow of people and goods.
The efficiency of an elevator system is defined in terms of the quantity of service (handling capacity) and
quality of service (passenger waiting time).

23.  Handling Capacity: The handling capacity of elevator system is the total number of passengers that the system can
transport within a certain period of time, (usually 5 minutes i.e. 300 seconds) during the peak traffic conditions (usually
the morning up-peak*) with a specified average car loading (usually 80% of the rated capacity of the elevator). The
handling capacity is usually expressed in percentage and is calculated as: Where
 HC = Handling capacity (percent)
 RC = Rated capacity of the elevator (lbs)
 I = Interval (seconds)
 P = Number of passengers carried on a round trip [the number of passengers carried on a round trip is established by the
designer for each project, and is typically obtained by dividing elevator capacity by 150 pounds per person].
Acceptable five-minute handling capacities during peak periods for general passenger elevator service can be taken as 10 to
16%. The criteria differs depending on the building type — residential apartments or offices. As a rough guide, the following
is acceptable:
 Residential Apartments / buildings: 7 to 9%.
 Premises without specific distribution traffic, such as mixed-tenancy office buildings with different working hours: 12 to
16%.
 Premises with excessive distribution traffic, such as single tenancy office buildings with the same working hours: 16 to
25%. *The up-peak mode is defined as elevator travel from lobby to upper floors.
 This is considered the worst case traffic scenario in elevator planning, typically in the morning as people arrive for work
or at the conclusion of a lunch-time period. The reason for employing the up peak model for sizing the lift is because
during up- peak period, the “handling capacity” of the lift system dominates the degree to which the traffic demand is
fulfilled. It is also believed that systems that can cope with the up-peak period are also sufficient to handle other traffic
conditions.

24.  Interval: Interval or waiting interval is the average time, in seconds, between successive lift car arrivals at the main terminal floor
with cars loaded to any level. The interval represents the theoretical longest time between elevator dispatches from the main lobby.
The interval is directly related to passenger waiting times and inversely related to the number of elevators in a group and is calculated by
the following equation
I = T/n
Where
• I = Interval
• T = round trip time for one elevator
• n = number of elevators in the group (in lift bank)
An acceptable interval during peak periods for ordinary occupancies can be taken as 25 to 30 seconds. An interval of 30 seconds means
that a car will be leaving the lobby every 30 seconds with a load of passengers. For a fixed handling capacity, large interval means small
number of lift cars and large lift car rated capacity.
Lift system with small number of lift cars but large rated capacity will result in inefficient use of energy during off peak hour. Imagine how
energy is wasted during off peak hours when there are frequent occasions of only a few people traveling in a large lift car.
 Round Trip Time
It is the time in seconds for a single car trip around a building, from the time the car doors open at the main terminal, until the car doors
reopen, when the car has returned to the main terminal after its trip around the building. The round trip time is estimated by adding
together such factors as acceleration and deceleration rates, full-speed running time, door opening time, door closing time, and passenger
entrance and egress times, multiplied by the probable number of stops.

25.  Average Waiting Time- Average waiting time is the average period of time, in seconds that an average passenger waits for a lift
measured from the instant that the passenger registers a landing call (or arrives at a landing), until the instant the passenger can
enter the lift. Typically this would be the sum of the waiting times of all the passengers divided by the total number of passengers.
It needs to be clearly recognized that Interval is NOT EQUAL TO Average Waiting Time. Average waiting time can be realistically
established only through a simulation.
 Elevator Capacity
The elevators capacity is derived from up-peak traffic analysis. The nominal capacity of the elevator and the rated maximum passenger
capacity is than known from manufacturer’s catalogues. Table below provides standard nominal capacities and passenger relationship:
The normal peak or number of passengers per trip is generally assumed as 80% of the rated capacity of the lift car. This does not mean
cars are assumed to fill only to 80% each trip but that the average load is 80% of rated capacity. The reason for assuming this 80% is that
the passenger transfer times are longer for a crowded lift car. For example, the last person usually takes a longer time to enter a fully
loaded lift car. Studies indicate that an 80% filled up car has the best performance in terms of round trip times.

26.  Elevator Car Foot Print Area
Maximum* inside Net Platform Areas for the Various Rated Loads
This table can be used to develop the inside dimensions of car enclosures. Note - To allow for variations in cab designs, an increase in the
maximum inside net platform area are not exceeding 5% shall be permitted for the various rated loads.

27.  Number of Elevators
Several numbers of passenger elevators are usually required in most buildings in order to cope with the traffic density.
The number of elevators is derived from a traditional traffic calculation during morning up peak. In this scenario, an
elevator loads at the lobby, delivers passengers to their floors, and returns empty for the next trip. The number of
elevators required shall be selected on the basis of a 25 to 30 second response waiting time interval between
elevators.
The general rules of thumb for estimating the number of elevators are:
• For buildings with 3 or less elevator stops and gross area of less than 5,000 m2 , provide a single elevator. (Note
however, if one elevator would normally meet the requirements in the facility where elevator service is essential, two
elevators shall be installed to ensure continuity of service. If financial limitations restrict the inclusion of a second
elevator, as a minimum, a hoistway for a future elevator is recommended).
• For buildings with 4 or more elevator stops and the gross area above 6000 m2 provide two elevators. If the gross
area of the building exceeds 10,000 m2 provide a group of three elevators.
• If distributed elevator configurations are used then the total number of elevators required shall be increased by
approximately 60% to account for the inefficiencies of the distributed arrangement and imbalances in demand.
Two lifts of 680 kg provide a better service than one 1360 kg. The large single lift would run only partly loaded
during the major part of the day with a resulting decrease in efficiency and increased running cost. The offset is that
although 2 lifts may be costly, require more foot print (space) and have less tenable area; the advantage is the lower
operating costs and better quality of service

28.  Speed of Elevators
Elevator speed is determined by travel distance and standard of service. The speed should be selected such that it will provide short
round time and 25 to 30 second interval, along with least number of elevators to handle the peak loads. The taller buildings above 20
floors may have high-speed lifts that do not stop at the first 10 floors. Car speed is chosen so that the driving motor can be run at full
speed for much of the running time to maximize the efficiency of power consumption. The overall speed of operation is determined by
the acceleration time, braking time; maximum car speed; speed of door opening; degree of advanced door opening; floor-leveling
accuracy required; switch timing and variation of car performance with car load. The general rules of thumb, for the recommended
elevator speeds for various travel distances are:

29.  Zoning of Elevators
Zoning implies subdivision of the floors of the premises into clusters of stops to be served by different
elevator cars. This creates the need for people traveling to floors within that zone to use the same lifts,
thereby reducing the probable number of stops made by the lifts. This in turn reduces the overall time lifts are
accelerating and decelerating. With the reduction in time spent in obtaining full speed or stopping from full
speed, the efficiency of the overall system is increased and so energy savings can be made.
For office buildings, a single elevator group can generally serve all floors in buildings up to 15 to 20 floors
depending on the building population. The taller building more than 20 floors (up to about 35 floors), are best
served by two different elevator groups; one serving the low rise and the other the higher floors. Such a
zoning arrangement would cut down on the number of stops per elevator, thus reducing round trip times and
increasing the handling capacity of each group. Other advantage is that the low rise group won’t need high
speed elevators, thus providing an economical and energy efficiency solution.
The same principle can also be deployed for low rise buildings of say 10 floors in a different way. A typical
example is separating elevator systems to serve even number floors and odd number floors. If the average
waiting time is too long, passengers will call for both lift systems and travel one floor by stair.

30. Location of Elevators
The location of elevators shall be such that they are easily accessible and convenient to circulation routes. When
planning the location of elevators, the following principles shall be observed:
• Elevators should be located so that the building entrances with the heaviest traffic shall have adequate elevator
service. Elevators should be as near to the center of the building area served as practicable, taking into consideration
the distance from the elevator bank or banks to the most distant functional areas do not exceed a maximum of 45
meters.
• Congestion at peak travel times is minimized by arranging the lift lobbies in a cul-de-sac of, say, two lift doors on
either side of a walkway, rather than in a line of four doors along one wall. For passenger cars, three across are
preferred, and not more than four in a row shall be used. Where four or more cars are required within a group, cars
shall be placed in opposite banks, opening into a common lobby.
• As a general guide, the lobby width between two banks of passenger elevators shall not be less than 3600 mm (~12
ft) and the lobby width between two banks of service elevators should not be less than 4200 mm (~14’).
• When designing the service core in relation to the floor plate, the designer must ensure that the elevator lobby
should not be used as a common or public thoroughfare at ground-floor level.
• Where elevators are accessed from corridors, they shall be located on one side of the corridor only and shall be set
back from the line of circulating corridors. Elevator ingress/egress shall be from a distinct elevator lobby and not
directly from a corridor
• Elevator lobbies generate noise and shall be acoustically isolated from areas sensitive to noise and vibration.
Elevators shall not be placed over occupied spaces as this shall require counter-weight safeties and reinforced pits.

31. Egress stairs shall preferably be located adjacent to elevator lobbies when possible.
• Any decentralized banks and/or clustering of elevators shall be planned to include at least two cars to maintain an acceptable dispatch
interval between cars and to ensure continuity of service.
• Elevators shall preferably provide positive separation between passenger and freight /service traffic flows.
• In facilities that utilize interstitial floors and mechanical penthouses, at least one elevator shall stop on these floors to facilitate
equipment maintenance and removal.
 Elevator Doors
The doors protect riders from falling into the shaft. The door opening shall be capable of opening doors at the rate of 0.9 m/s. This is a
capability speed, with actual speed being adjusted to meet the requirements of the specific installation. The closing speed shall be set
per ASME/ANSI A17.1. All power operated doors shall be equipped with an automatic reopen device for passenger protection.
Door configuration and door opening
The most common configuration is to have two panels that meet in the middle, and slide open laterally.
• Single-speed bi-parting doors are typically used in the larger capacity ranges and when dictated by the shaft and platform
arrangement. Their operating speed is generally faster than side-acting doors.
• Two-speed bi-parting doors have the fastest action and are used where a wide opening is required; they are common on large
passenger elevators and service elevators. A cascading configuration is sometimes used for wider opening of service elevators where
the doors are tucked behind one another, and while closed, they form cascading layers on one side.
The clear opening (width and height) of an entrance depends on its application.
For passenger elevators and handicap access, a minimum door opening width of 1070 mm (3'-6") and height of 2135mm (7’) is
recommended.
• Combined passenger/ service elevators typically have doors at least 1220 to 1320 mm (4'-0" to 4'-4") wide and 2135 to 2440 mm (7'-
0" to 8'-0") high.

32. List of the top elevator manufacturing companies in India
 Kone
 Fujitec
 Mitsubishi electric
 Schindler elevator
 Otis elevator
 Hitachi
 Kinetic Hyundai
 ESCON elevators
 Expedite automation LLP
 ThyssenKrupp elevator India