Glossary of Lift Traffic Design Calculations – Part One



This glossary will help you to understand the technical meaning for any term or expression which will facilitate your understanding for the Lift Traffic design calculations.

Please read this glossary carefully because you will need to come back to it while reviewing the articles of this course: Elevators Traffic Design and Motor power sizing Calculations.





Glossary of Lift Traffic design calculations – Part One 





Term
Definition
Ambient temperature

The temperature of the surrounding air at a particular point in time.
angle of inclination
The maximum angle to the horizontal in which the steps move on the inclined part of an escalator
Arrangement: criss-cross
An escalator installation where the adjacent units have boarding and alighting at opposite ends from each other
Arrangement: multiple parallel
An arrangement of escalators where a number of installations running in both directions are located parallel to each other.
Arrangement: zig-zag
An escalator installation where the adjacent units have boarding and alighting at opposite ends from each other.
Arrival rate: down peak passenger

The number of passengers arriving at an elevator system for service during a five minute peak period, when traffic is predominately in the down direction.
Arrival rate: interfloor passenger

The number of passengers arriving at an elevator system for service during any five minute period, with no dominant traffic pattern.
Arrival rate: up peak passenger
The number of passengers arriving at an elevator system for service during a five minute peak period, when traffic is predominately in the up direction.

Arrival rate: up peak percentage
The number of passengers arriving at the main floor of an elevator system for service during the worst five minute period during an up peak traffic condition expressed as a percentage of the total building population.
Automatic by-pass.
A feature of an elevator supervisory control system, which causes the elevator car to automatically by-pass landing calls
under certain circumstances, such as when a car is fully loaded and has no room for further passengers, or a car is making a special trip to serve a demand at a distant floor e.g. lobby service, heavy demand call etc.
automatic control
A generic term, which is used to define any error activated, power amplifying, negative feedback, closed loop control system.
Automatic pushbutton control

A term used to define the simplest means of automatically controlling a single car, where a car may be called
 No a floor by the pushing of a landing pushbutton (provided it is not already busy) and commanded to travel to a destination floor by the operation of a car call pushbutton.
Auxiliary supply
An alternative supply to the main power supply source.
Average car load
The total number of passengers carried in one direction of travel, divided by the number of trips in that direction, averaged over a certain time period, usually taken as five minutes, hence up peak or down peak average car load
Balanced traffic
A term used in connection with the interfloor traffic condition to indicate that the traffic flows in both up and down directions are substantially equal.
Bank (1)
A number of groups of cars placed physically together, with each group serving a particular zone of a building, where more than one group may serve the same zone and it is possible to have a bank comprising one group only.
Bank (2)
A number of escalators in close proximity.
Basement service
Service provided to a floor or floors below the main terminal in a building, which may be restricted at times in order to improve the service to other parts of the building.
bi-directional
The ability to operate in two directions
Bottom landing
The lower end of an escalator where passengers board or exit.
Bottom terminal landing
The lowest landing in a building, which an elevator serves, where passengers may enter and leave the car.
Building: commercial
A building in which people work; such as offices, stores, industrial.
Building: institutional
A building in which people receive a service; such as hospitals, school, universities, public buildings.
Building: residential

Buildings in which people live; such as houses, hotels, flats, hostels.
Building: retail
A building from which a product or service is sold.
By-pass floors
Floors, which are by-passed in a building, as a result of a supervisory control action or because the car is fully loaded.
Cab
That part of an elevator car, comprising a self-contained enclosure, mounted on an elevator platform, in which passengers or goods are carried.
Call
A demand for service by a passenger, which is entered into an elevator supervisory control system, by the passenger pressing either a landing or car call pushbutton
Capacity: handling (elevator)
The total number of passengers that an elevator system can transport in a period of five minutes during the up peak traffic condition with a specified car loading, usually taken as 80% of rated capacity.
Capacity: rated
The maximum legal load, which an elevator car is permitted to carry measured in a number of passengers or a specific weight in kg.
Capacity: theoretical escalator handling
The total number of passengers that an escalator system can transport in theory in the knowledge of factors such as step width, speed, rise, etc.
Car
The load carrying unit comprising enclosure (cab), car frame, platform and door(s).
Car allocation.

The action of an elevator supervisory control system, when allocating a specific car to a set of landing calls for service.
Car travel distance

The distance that the car of an hydraulic elevator travels from the lowest landing to the top landing, excluding overruns or ram travel.

Car: free
A car to which the supervisory control system has not allocated any further calls and is therefore free to be given a new assignment.
Car: next
Usually the next car to leave a main floor as defined by the group supervisory control system.
Circuit protective conductor (CPC)
An earthing cable connecting an exposed conductive part of an installation to the main earth terminal.
Computer aided design (CAD)
A system where a digital computer carries out the tedious and time consuming aspects of an engineering design.
Control logic
The defined sequence and precedence of escalator operations, both manually and automatically initiated for normal, maintenance and fault conditions.
Control: directional collective
Where landing calls are registered on a set of up and down landing call push buttons, the landing and car calls being registered in any order but are answered strictly in floor sequence in the direction of travel, taking account of the direction of travel of the registered landing calls.
Control: drive.
The system which controls the starting, stopping, direction of motion, acceleration, retardation, and speed of the elevator car or escalator.
Control: group supervisory

A control system which commands a group of interconnected elevator cars with the aim of improving the elevator system performance.
Control: group collective
A simple form of group control system, where two (duplex) or three (triplex) cars are interconnected and collectively controlled, but providing a means of allocation of the best placed car to each landing call.
Control: non-collective
The simplest form of control whereby a car will only answer a landing call if it is available.
Control: on-call
An elevator supervisory control system where cars are dispatched to serve landing calls according to a fixed or tunable algorithm.
control: scheduled
An elevator supervisory control system where cars are dispatched to serve landing calls according to a fixed schedule from terminal floors.
control: simplex collective, [syn: non-selective]
Where landing calls are registered on a single set of landing call push buttons, and landing and car calls may be registered in any order, but are answered strictly in floor sequence in the direction of travel, passengers being unable to indicate their desired direction of travel.
Control: supervisory

An open loop control system which is used to manage a plant or process, such as elevator traffic control system.
Control: up-distributive, down-collective
Where a single set of landing push buttons indicate a down demand on floors within a building, thus allowing the elevator system to distribute upward going passengers when travelling in the up direction and to collect downward going passengers when travelling in the down direction.
Controller
A controlling device in the form of an electrical panel, normally located in the upper head of a compact escalator and consisting of the electrical devices required to assure proper operation of the drive mechanism.
Controller: programmable
A controlling device which can have its operating rules altered by means of a program.
Conveyor
An endless moving belt for the movement of goods or people.
car
part of a lift that carries passengers and/or other loads
control system
system that controls the manner in which the lift and doors operate
data-logging
The process of logging (acquiring) and analyzing data automatically using a digital computer based equipment.
Direct on line start (DOL)
Motors that are connected directly to the full voltage without some form of resistance or other current or voltage limiting device in the circuit.
Diversity factor
A factor which may be applied to reduce the sizing of services, for example electric power cables, on the basis of a mathematical probability that not all connected equipment will require serving at the same time.
down peak
A down peak traffic condition exists, when the dominant or only traffic flow is in the downward direction, with all or the majority of the passengers leaving the building at the main terminal floor of the building.
Drive controller
A separate controller provided on some larger escalators containing electrical and/or electronic components or devices which interpret the outputs from the logic controller and set the drive motors speed and direction.
Drive machine (elevator)
A power unit which provides the means for raising and lowering the car and which comprises: the electric motor or hydraulic power unit; gearing, brake; sheave or drum; couplings and bedplate.


Drive machine (escalator)
The combination of motor and gear reduction unit which forms the drive mechanism for all moving parts on an escalator.
duplex
Two interconnected cars, sharing a common signaling system, controlled under a simple group control system operating under directional collective principles.
elevator, [syn: lift]
A permanent lifting equipment, serving two or more
landing levels, provided with a car or platform for the transportation of passengers and/or freight, running at least partially in rigid guides either vertical or inclined to the vertical by less than 15 degrees
Elevator: electric
A power elevator, which uses an electrical drive machine to provide energy for the movement of the car.
Elevator: electro-hydraulic
A direct plunger machine, where liquid is directly pumped under pressure into the cylinder by a pump driven by an electric motor.

elevator: firefighting
An elevator, which may be supplied with additional fire resistant protection, installed in a fire protected zone and designated to have controls that enable it to be used under the direct control of the firefighting services for emergency purposes.
Elevator: fireman’s
An elevator, which may or may not be supplied with additional fire resistant protection, designated to have controls that enable it to be used under the direct control of the firefighting services for emergency purposes.
Elevator: freight
An elevator primarily used to transport freight and goods, where only the operator and persons necessary to load and unload the freight are permitted to travel.
Elevator: gravity.
An elevator where gravity is used as the motive force to move the car.
Elevator: hand
An elevator where manual energy is used to move the car.
Elevator: hydraulic
A power elevator, which uses the energy stored in a liquid under pressure to provide the energy for the movement of the car.
Elevator: inclined
An elevator which travels at an inclination to the vertical of 15° or more.
Elevator: indirect acting.
A hydraulic elevator where the plunger or cylinder is indirectly connected to the platform or car frame by ropes or chains.
Elevator: maintained-pressure hydraulic.
A direct plunger elevator where liquid under pressure is available for application to the cylinder at all times.
Elevator: multideck
An elevator having two or more compartments located above each other to form a multi-level stack.
Elevator: observation
An elevator designed as an architectural feature to give passengers a panoramic view while travelling in a partially enclosed well.
Elevator: passenger
An elevator primarily used to carry passengers other than the operator (if any) goods and restricted classes of passengers (such as freight handlers, employees) may be carried.
Elevator: power
An elevator utilizing energy other than gravitational or manual to provide motion for the car.
Elevator: service
A passenger elevator used to transport materials, which conforms to the standards for passenger conveyance, but is often specially strengthened to carry freight or goods.
Elevator: sidewalk
An elevator of the freight type used to carry materials, except automobiles, between a street level and a level or levels below.
Elevator: stair

Elevators provided for persons with impaired mobility, which can be permanently or temporarily installed on a stairway, which provide a seat for the person to ride on.
Elevator: wheelchair
A platform elevator, which can be fitted to a stairway for the transportation of wheelchairs and which generally, can be folded away when not in use.
Escalator

A power driven endless moving stairway inclined at between
28° and 35° for the short range upward and downward transportation of passengers.
Escalator: compact.
An escalator with the drive machine incorporated within the bounds of the truss and typically without separate machine areas.
Escalator: heavy duty public service
A public service escalator with major non wearing components suitable for operating for 40 years in an underground railway environment.
Escalator: spiral
An escalator that can follow a curved path.
Escalator: wheelchair
An escalator designed to transport a wheelchair.
entrance
complete landing door assembly, together with its surround
Floor: bottom terminal
Lowest floor in a building zone from which elevator cars can load and unload passengers.
Floor: bypass
Floors at which a landing call has been registered, but which are passed by the elevator car under circumstances when the car is fully loaded (load bypass) or when the car has other higher priority duties to perform (control bypass).
Floor: car

The under surface of the interior of an elevator car, on which passengers stand.
Floor: dispatch

Floors in an elevator zone, often the terminal floors, from which cars were dispatched under the control of the scheduling supervisory control system.
Floor: express zone terminal
The lowest floor of a high rise zone in a building which is served by an elevator car after it leaves the main terminal floor.
Floor: heavy duty
A floor at which a considerably larger than average number of passengers are demanding service often detected by successive cars leaving the floor fully loaded or the immediate re-registration of a landing call as soon as a car has left a floor.
Floor: highest
The highest, occupied or otherwise, floor within a building.
Floor: highest reversal
The floor at which a car reverses direction, when
travelling in an upward direction having completed its last car call, in preparation to serve registered down landing calls
Floor: lowest
The lowest, occupied or otherwise, floor within a building. preparation to serve registered up landing calls, particularly during an interfloor traffic condition.
Floor: main
The main or principal floor of a building.

Floor: parking
A floor at which an elevator car is parked when it has completed serving its car calls and the supervisory control system does not reallocate it to serve further landing calls.
Floor: terminal
The highest and lowest floors at the extremities of travel of an elevator car within a building zone.
Floor: top terminal

Highest floor in a building zone from which elevator cars can load and unload passengers.
Flow divider
Where the oil line is divided into two or more lines either through branching pipe fittings or a manifold.
Flywheel
A rotating mass usually attached to the electric motor shaft, sized to provide inertia in the system sufficient to prevent a sudden stop of the low inertia motor rotor, if the power is removed from the motor when running full speed.
Flywheel (1)
A disc located on the motor shaft of an elevator and normally used for hand winding.
Flywheel (2)
A disc located on the motor shaft of an escalator.
Foundation
The reinforced concrete base on which the escalator truss supports are mounted.
Frame: cantilevered car
The type of frame that is only guided or supported on one side, with the cabin support beams cantilevered out from the uprights. See also rucksack elevators.
Frame: car. [syn: sling]
A supporting frame consisting of stiles, cross beam, safety plank and platform to which the guide shoes, car safety and hoisting ropes or hydraulic plunger or cylinder is attached.
Frame-size
Commonly used to indicate the size of an electrical drive motor.


In the next article, we will explain Glossary of Lift Traffic design calculations – Part Two. Please, keep following.

The previous and related articles are listed in below table:
Subject Of Previous Article
Article
Applicable Standards and Codes Used In This Course,
The Need for Lifts,
The Efficient Elevator Design Solution
Parts of Elevator System Design Process
Overview of Elevator Design and Supply Chain Process.

The Concept of Traffic Planning,
The (4) Methods of Traffic Design Calculations,
Principles of Interior Building Circulation:
A- Efficiency of Interior Circulation

B- Human Factors

C- Circulation and Handling Capacity Factors:
Corridor handling capacity,
Portal handling capacity,
Stairway handling capacity,
Escalator handling capacity,

Passenger Conveyors (Moving Walkways and Ramps) handling capacity,
Lifts Handling Capacity.
D- Location And Arrangement Of Transportation Facilities

Traffic design calculations:
1- Calculation of the Number of Round Trips for a Single Car,
2- Estimation of Population,
3- Calculation of the Average Number of Passengers per Trip (P),
4- Calculation of the Uppeak Handling Capacity (UPPHC),
5- Calculation of the Waiting Interval (Passenger Waiting Time),
6- Calculation of The percentage population served (%POP),



7- Estimation of Arrival Rate,
8- Calculation of the Round Trip Time RTT,
9- Calculation of the quality of service (Grade of Service)
Methods for Lift Traffic Design Calculations:
First Method:  The Conventional Design Method

Second Method: The Iterative Balance Method
How To Size The Lift Motor KW/HP:
1- Professional Formulas Method,
2- Baldor Formulas Method,
3- Equivalent Weight Method,
4- Buildings Energy Code (BEC)’S Tables Method,
5- Baldor Tables Method,
6- Curves Method.




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