G.L. BAJAJ GROUP OF INSTITUTIONS,MATHURA

Definitions Regarding Lifts

Submitted By:-Anubhav GuptaArchit VarshneyArvind SinghAyushi YadavGauri Raj RajeshwariBhavya SharmaKunal UpadhyayMegha Sharma

WHAT IS LIFT/ELEVATOR?• An elevator/lift is a type of

vertical transport equipment that moves people or goods between floors/levels of a building or other structure.

• Elevators are generally powered by electric motors that either drive traction cables or counterweight systems like a hoist, or pump hydraulic fluid to raise a cylindrical piston like a jack.

• a machine used for carrying people and things to different levels in a building.

WHAT IS CAR

SIZE OF THE CAR• The width of car is determined by the width of

entrance, and the depth of car is regulated by loading per sq.mtr.

• Permissible. Centre opening door are the most practicable and most efficiency entrance with for passenger lifts.

Where passengers ride up and down

QUANTITY OF SERVICEThe quantity of service is a measure of the passenger handling capacity of a vertical transport system. It is measured in terms of the total number of passengers handled during each five minutes peak period of the day.

QUALITY OF SERVICEThe quality of service on the other hand is generally measured by the passenger waiting time of the various floors. Quality of service or Acceptable interval

20 to 25 seconds-Excellent30 to 35 seconds-Good 35 to 40 seconds-Fair 40 to 45 seconds-Poor

Over 45 seconds-Unsatisfactory

LIFT TRAFFIC• A lift traffic analysis studies the performance of a group of lifts, based on assumptions about the expected

traffic situation.• The main performance measurements are quantitative  (handling capacity) and qualitative (waiting time).• Handling Capacity is expressed as the percentage of the building population the group of lifts can cope with

over a given time period (usually in 5 minutes).• Waiting time is exactly that. It is the waiting time for a lift to arrive in response to pressing a call button.

• The more accurate the passenger movement can be modelled, then the more accurate will be the results of the traffic analysis.

• Once these are modelled an accurate calculation of the lift performance can be made.

• The outputs of a traffic analysis will give an accurate indication of the quality and quantity of lift service provided i.e. what the waiting times are and what percentage of the building population can be transported by the lifts in a given time period.

CARRYING CAPACITY OF LIFTS• The capacity of a standard elevator can vary somewhat depending on how it was built and where it is used,

but in general the range is between about 454 to 2,722 kg.• Some of the biggest factors that influence this number are the elevator’s floor dimensions, what it’s made of,

and how it is supported.• Standard elevators in small residential buildings or in private residences — machines that ascend no more

than four or five floors — tend to be the smallest, and as such usually have the lowest limits.• Lifts in taller structures and those that are designed to bring people and materials up skyscrapers are usually

built differently and can typically sustain much more.• Freight elevators tend to have the most robust capacities. Engineers usually determine the upper limits based

on calculations related to the resistance and pull of the system as a whole, and following these limits is very important to overall safety.

• Overloaded elevators can lose control and function improperly, which can lead to accidents and potentially serious injuries.

RATED SPEED OF LIFTS• The speed in feet (or meters) per minute at which a device, apparatus, conveyance, elevator, etc., is desi

gned to operate in the upward direction with the rated load.• It is dependent upon quality of service required and the quality of service desired. Therefore, no set

formulae for indicating the speed can be given.• Some general guidelines are for different buildings are as follows:

Office Building Passenger LiftsSl.

No.No. of Floors Recommended

Speed1. 4 to 5 floors 1 MPS2. 6 to 12 floors 1.5 MPS3. Above 12 floors Above 1.5 MPS

Residential Building Passenger LiftsSl. No.

No. of Floors Recommended Speed

1. 4 to 8 floors 1 MPS2. 8 to 12 floors 1.5 MPS3. Above 12 floors Above 1.5 MPS

Hospital Lifts (Bed cum Passenger Lifts)Sl. No.

No. of Floors Recommended Speed

1. Upto 4 floors 0.5 MPS2. 5 to 8 floors 0.75 MPS3. Above 8 floors 1 MPS

Goods LiftsSl. No.

No. of Floors Recommended Speed

1. Upto 6 floors 0.5 MPS

2. Above 6 floors 0.75 MPS

ROUND TRIP TIME (RTT)Round trip time, that is, the average time required by each lift in taking one full load of passengers from ground floor, discharging them in various upper floors and coming back to ground floor for taking fresh passengers for the next trip.

RTT is the sum of the time required in the following process :a)Entry of the passengers on the ground floor,b)Exit of the passengers on each floor of discharge,c)Door closing time before each floor of discharge,d)Door opening time on each discharging operation,e)Acceleration periods,f)Stopping and leveling periods,g)Period of full rated speeds between stops going up, andh)Period of full rated speeds between stops going down.It is observed that the handling capacity is inversely proportional to the waiting time which in turn is proportional to RTT.

The round trip time can be decreased not only by increasing the speed of the lift but also by improving the design of the equipment related to opening and closing of the landing and car doors, acceleration, deceleration, levelling and passenger movement.

CALCULATION OF RTTCalculation of R.T.T. The most probable number of floors on which lift may have to be stopped is given by statistical formula:

Sn = n [ 1-(n-1)/n)Np]Where Np= Total number of passengers entering the car at ground floor (Entrance Lobby) during peak period which is equal to car capacity.n = Total number of floors served above ground floor.Sn = Most probable number of stops.

Some More Different Terms Of A Car Of A Lift

COP ApronKick Plate

THANK YOU…!