LIFTS & ESCALATORS



INSTALLATION OF LIFTS AND ESCALATORS

20.0. Introduction

This section covers the essential requirements of installation of lifts and escalators in buildings. This section shall however be read with section 23 fire protections from fire safety requirements point of view

Emphasis has been laid on coordination between the architect / engineer and the lift manufacturer to arrive at the number and position of lifts for attaining optimum efficiency in serving the building with safety.

The information contained in this section is largely based on the following Indian Standards:

IS:1860-1980 : Code of practice for installation, operation and maintenance of electric passenger and goods lifts (second revision)

IS:2332-1972: Nomenclature of floors and storeys (first revision)

IS:3534-1976: Outline dimensions of electric lifts (first revision)

IS:4591-1968: Code of practice for installation and maintenance of escalators

20.1. Scope

This section covers the essential requirements for the installation operation and maintenance and also inspection of lifts (passenger lifts, goods lifts, hospital lifts, service lifts and …. water) and escalators so as to ensure safe and satisfactory performance.

This section gives information that should be exchanged among the architect, the consulting engineer and the lift escalator manufacturer from the stage of planning to installation including maintenance.

Note: The provisions given in this section are primarily for electric traction lift; however, most of these provisions are also applicable to hydraulic lifts (see good practice [8-5(1)].

20.2. Terminology - Please refer Section 0.2.

20.3. General

20.3.1. The appropriate aspect of lift and escalator installation shall be discussed during the preliminary planning of the building with all the concerned parties, namely, client, architect, consulting engineer and/ or lift / escalator manufacturer to furnish the architect and/ or consulting engineer with the proposed layout or vice-versa.

20.3.2. Exchange of Information

If the proposed installation is within the scope of 6, the guidelines laid down together with Fig.1 will enable the preliminary scheme for the installation to be established.

Figure 1 show only some of the typical arrangements and variations are possible with respect to number of lifts and the layout.

Although the recommended outline for the various classes of lifts given in 6 enables the general planning details to be determined by the architect, these should be finally settled at the earliest possible stage by detailed investigation with the purchaser’s representative reaching agreement with the lift maker where necessary before an order is finally placed. This will enable a check to be made and information to be exchanged on such vital matters as:

a) The number, capacity, speed and disposition of the lifts necessary to give adequate lift service in the proposed building.

b) The provision of adequate access to the machine room

c) The loads which the lift will impose on the building structure, and the holes to be left in the machine room floor and cut-outs for wall boxes for push-buttons and signals

d) The necessity for and type of insulation to minimize the transmission of vibration and noise to other parts of the building

e) The special requirements of local authorities and other requirements set out in the ‘planning permit’

f) The need for the builder to maintain accuracy of building as to dimensions and in plumb

g) The periods of time required for preparation and approval of relevant drawings for manufacturing and the installation of the lift equipment

h) The requirement for fixing guide brackets to the building structure

j) The time at which electric power will be required before completion to allow for testing

k) The requirements for electrical supply feeders etc;

m) The requirements for scaffolding in the lift well and protection of the lift well prior to and during installation of equipment; and

n) Delivery and storage of equipment.

20.3.3. Information to be provided by Architect or Engineer - As a result of preliminary discussion, the drawings of the building should give the following particulars and finished sizes:

(a) Number of lifts and size and position of lift well; (b) Particulars of lift well enclosure; (c) Size, position, number and type of landing doors;  (d) Number of floors served by the lift; (e) Height between floor levels; (f) Number of entrances; (g) Total headroom;  (h) Provision of access to machine room, (i) Provision of ventilation and, if possible, natural lighting of machine room; (j) Height of machine room; (k) Depth of lift pit; (l) Position of lift machine, above or below lift well;  (m) Size and position of any trimmer joists or stanchions adjacent to the lift well as each floor;  (n) Size and position of supporting steel work at roof levels; (o) Size and position of any footings or grillage foundations, if these are adjacent to the lift pit; and (p) In the case of passenger lifts whether the lift cage is required to carry household luggage, such as refrigerator, steel almirah, etc.

The lift lobby should be designed appropriately since this has bearing on the traffic handling especially when more number of lifts are involved.  In a dual line arrangement (lifts opposite to each other) the lobby can be between 1.5 times to 2.5 times the depth of one car. Typically, the more the number of lifts the bigger the multiple to be used. As an example a quadruplex may use 1.5 to 2 times where as an octoplex will need 2 to 2.5 times. For in-time (single line) arrangements, the lobby can be typically half of the above recommendations.

It is preferable that the lift lobby is not used as a thoroughfare but in such cases the lift corridor shall take into account space for people who are moving.

The architect / engineer should advise the lift manufacturer, if the Authority (see 20.4.1) has any special requirements regarding lifts in buildings in the administrative area concerned.

The information contained under 20.3.2 and 20.3.3 is applicable for the installation of lifts only and in the case of escalator installations, the drawings shall provide the appropriate information.

The architect / engineer should inform the lift / escalator manufacturer of the dates when the erection of the lift / escalator may be commenced and is to be completed so that sufficient time is allowed for the manufacture and erection of the lift/ escalator.

When submitting application for a building permit to the local Authority, the building plans shall include the details of lifts (No. of lifts duly numbered, location, type, type of doors, passenger capacity and speed).

When enquiring for and ordering an electrical lift in accordance with this section, the particulars given below shall be furnished:

20.3.4. Particulars of lifts

1. Passenger, goods or service …………………………………………………

2. Number of lifts required……………………………………………………

3. Load: number of persons…………….kg………………………………………

4. Rated speed……………………………m/s……………………………………

5. Travel in m………………………………………………………………

6. Serving.……………………floors……………..entrance…………………

7. Number of floors served …………………………………………………………

8. Method of control …………………………………………………………………

9. Position of machine room…………………………………………………………

10. Sizes and position(s) of lift well(s) ………………………………………………

11. Position of counterweight…………………………………………………………

12. Size of car platform……………………………or Internal size of lift car………

13. Construction, design and finish of car bodywork ………………………………

14. Car entrances:

a). Number, size and type of doors………………………………………………

b). Power or manual operation……………………………………………………

15. Car light ……………………………………………………………………………

16. Ventilation of the car………………………………………………………………

17. Call indicator …………………………….position indicator in car………………

18. Landing entrances:

a). Car open in front only or open through……………………………

b). Number, size and type of doors, or shutters………………………

c). Power or manual operation or automatic closing…………………

19. Electric supply

a). Power –           volts, AC/DC ………………..phase……………………….…cycles,

b). Wire system……………………………………………………………

c). Lighting –

d). Whether neutral wire available for control circuit?

e). Are premises subject to Lifts Act / Rules?

f). Proposed date for commencement on site ……………………………………

g). Proposed date for completion……………………………………………………

h). Additional items, if required………………………………………………………

i). Booklet giving complete details of maintenance schedule and circuit diagram where so specified………………………………………………………

20.3.5. Working drawings to be prepared by the lift / escalator manufacturer –The lift escalator manufacturer requires sufficient information for the preparation of working drawings and is usually obtained from architect’s drawings supplemented by any information obtained from the site and by collaboration with the other contractors (see20.3.2 and 20.3.3)

20.3.6. Working drawings showing the layout of lift / escalator duly numbered- Details of building work, for example, holes in walls for guide fixing, holes in machine room floor for ropes conduits, recesses for landing sills, supports for lift / escalator manufacturer to the architect / engineer for written approval.

20.3.7. Electrical requirementFor information of the electrical engineer, the lift / escalator manufacturer should advise the architect / engineer of his electrical requirements.  This information should be available early in the planning stage so that the electrical supply requirements of the lift(s)/ escalator(s) may be included in the electrical provisions of the building and that suitable cable and switchgears may be provided. .

20.4. Essential requirements

20.4.1. Conformity with Lifts Acts and Rules - The installation shall be generally carried out in conformity with Lifts Act and Rules there under, where they are in force.

It is the responsibility of the owner of the premises where the lift will be installed, to obtain necessary permission from the local Authority before and after the erection of lifts and for subsequent operation of lift(s).

20.4.2. Conformity with Indian Electricity Rules - All electrical work in connection with installation of electric lifts shall be carried out in accordance with the provisions of Indian Electricity Act, 1910 and shall also comply with the other provisions of section 13- Electrical installations.

20.4.3. Conformity with Indian Standards - All materials, fittings, appliances etc used in electrical installation shall conform to Indian Standard specifications wherever these exit. In case of materials for which Indian Standard specifications do not exit, the materials shall be approved by the competent authority. For detailed specification for lifts, reference shall be made to accepted standards.

20.4.4. Conformity with Fire Regulations

The installation shall be carried out in conformity with Section 23 on Fire Protection and local fire regulations and rules there under wherever they are in force.

20.4.5. Factor of Safety – The minimum factor of safety for any part of the lift shall not be less than five. Higher factor of safety for various parts shall be applicable in accordance with accepted standards..

20.4.6. Additional Requirements for Passenger and Goods Lifts

20.4.6.1. Bottom and Top Car Clearances

Bottom Car Clearance – When the car rests on its fully compressed buffer there shall be a vertical clearance of not less than 600mm between the pit floor and the buffer striker plate or the lowest structural or mechanical part equipment or device installed. The clearance shall be available beneath the whole area of the platform except for:

a) guide shoes or rollers, safety jaw blocks, platform aprons, guards of other equipment located within 300 mm measured horizontally from the sides of the car platform; and

b) Compensating sheaves.

Provided that in all the cases, including small cars, a minimum clearance of 600mm is available over a horizontal area of 800 mm x 500 mm.

Provided also that in all the cases, when the car rests on its fully compressed buffers, there shall be a vertical clearance of not less than 50mm between any part of the car and any obstruction of device mounted in the pit.

Top car clearance – The vertical clearance between the car cross-head and the nearest overhead obstruction within 500mm measured horizontally to the nearest part of the crosshead when the car platform is level with the top landing, shall be not less than the sum of the following;

a) The bottom counterweight runby,

b) The stroke of the counterweight buffer used.

c) One-half of the gravity stopping distance based on:

1) 115 percent of the rated speed where oil buffers are used and no provision is made to prevent the jump of the car at counterweight buffer engagement; and

2) Governor tripping speed where spring buffers are used.

Where there is a projection below the ceiling of the well and the projection is more than 500 mm, measured horizontally from the centre line of the cross-head but over the roof of the car, a minimum vertical clearance not less than that calculated above shall also be available between the roof of the car and the projection.

Provided that the vertical clearance between any equipment mounted on top of the car and the nearest overhead obstruction shall be not less than the sum of the three items (a), (b) and (c) as calculated above plus 150 mm.

20.4.6.2. Bottom, Run by for Cars and Counterweights - The bottom runby of cars and

counterweights shall be not less than the following:

a) 150mm where oil buffers are used;

b)  Where spring-buffers are used;

1) 150 mm for controls.

2) Not less than the following for controls.

Rated speed (m/s)   Run by (mm)

Upto 0.125                   75

0.125 to 0.25               150

0.25 to 0.50                 225

0.50 to 1                      300

20.4.6.3. Maximum Bottom Runby – In case shall be maximum bottom runby exceed the following:

a) 600mm for cars; and

b) 900mm for counterweights

20.4.6.4. Top Counterweight Clearances – The top counterweight clearance shall be not less than the sum of the following four items:

a) The bottom car runby

b) The stroke of the car buffer used;

c) 150mm and

d) One-half the gravity stopping distance based on

1) one hundred and fifteen percent of the rated speed where oil buffers are used and no  provision is made to prevent jump of the counterweight at car buffer engagement; and

2) governor tripping speed where spring buffers are used

20.4.6.5. Additional Requirements for Service Lifts

Top and Bottom Clearances for Car and Counterweights

(1). Top car Clearance – The top car clearance shall be sufficient to avoid any protruding part fixed on the top of the car coming in direct contact with the ceiling or diverting sheave.

The clearance shall be calculated taking into account the following and shall not be less than the sum of the following four items:

  1. The bottom counterweight runby
  2. The stroke of the counterweight buffer used
  3. The dimensions of the portion of the diverting sheave hanging underneath the ceiling in the lift well and
  4. 150mm for compensating for gravity stopping distance and future repairs to the rope connections at counterweight and at the car or at the suspension points.

(2). Bottom car clearance – The bottom car clearance shall be maintained in such a way that the counterweight shall not come in contact with the ceiling or any part hanging underneath the ceiling, when the car completely rests on fully compressed buffers, provided the buffers are spring type mounted on solid concrete or steel bed.

In case of wooden buffers the bottom car clearance shall be maintained in such a way that the total downward travel of the car from the service level of the immediate floor near the pit, shall not be more than the top counterweight clearance, when the wooden buffers are completely crushed.

Top counterweight clearance – The top clearance for the counterweight can be calculated taking into account the following and shall not be less than the sum of the following three items:

a) Car runby (b) Compression of the buffer spring or height of the wooden block used as buffer, and (c) 150mm to compensate for gravity stopping distance for counterweight and any future repairs to rope connections at the counterweight at the car ends or at the suspension points.

(3). Runby for Cars and Counterweights – The bottom runby for cars and counterweights shall not be less than 150mm

(4). Maximum bottom runby – In no case shall the maximum bottom runby exceed 300mm.

(5). In order to maintain a safe work environment, and to avoid potential hazards, the following shall be provided:

a) Caution sign shall be installed in the areas listed below where potential hazard exists;

(i) Trip hazard in machine room; and (ii) Caution notice against unauthorized use of rescue devices (for example, brake release device)

b) Use the hard hats for entry in pit and car top during construction period

c) Warning sign shall be provided on the controller so also eliminate, the possibility of contact with any exposed concealed power circuit

d) Car top barricade system shall be provided as primary protection against fall, on car top

e) Whenever work is carried out on the lift and lift is not required to be moved on power, notice shall be put on electrical main switch indicating requirement of de-energized condition

f) During lift installation / maintenance, protection against fall shall be provided with suitable barricades for all open lending entrances.

20.4.6. Planning for Dimensions

20.4.6.1. General – The dimensions of lift well have been chosen to accommodate the doors inside the well which is the normal practice. In special cases, the door may be accommodated in a recess in the front wall, for which prior consultation shall be made with the lift manufacturer.

20.4.6.2. Plan Dimensions

All plan dimensions of lift well are the minimum clear plump sizes. The architect / engineer, in conjunction with the builder, shall ensure that adequate tolerances are included in the building design so that the specified minimum clear plump dimensions are obtained in the finished work.

Note: The words ’clear plumb dimensions’ should be noted particularly in case of high rise buildings.

Rough opening in concrete or brick walls to accommodate landing doors depend on design of architrave. It is advisable to provide sufficient allowances in rough opening width to allow for alignment errors of opening at various landings.

When more than one lift is located in a common well, a minimum allowance of 100mm for separator beams shall be made in the widths shown in Tables 1 to 4.

Where the governor operated counterweight safety is required under conditions stipulated in good practice, the tabular values should be revised in consultation with the lift manufacturer.

For details specification of lifts reference shall be made to accepted standards 

The outline dimensions of machine room, pit depth, total headroom, overhead distance and sill are specified in Tables 1 to 4 as given below:

Passenger lifts

Table 1 and 1A

Goods lifts

Table 2

Hospital lifts

Table 3

Service lifts

Table 1 and 1A

Dumb waiter

Table 4

Note 1: The above tables have been established for a maximum travel of 30 m. for heights exceeding 30 m lift experts may be consulted.   

Note 2: Minimum floor-to-floor height for horizontally sliding door is f + 750 mm and for vertically by – passing door is 15 f + 250 mm, where ‘f’ is clear entrance height in mm.

Note 3: when more than one lift comes in a bank of lift, the machine room dimensions will be as follows:

Width = N x C + (N-1)100 + 1500

Depth = D + 2500

Where

N = number of lifts in bank of lifts.

C = width for each lift in mm, and

D = depth for each lift in mm,

Note 4: Fireman’s lift shall be provided for all buildings more than 24 meters in height. The capacity of the fireman lift shall not be less than less than 8 passengers. The dimensions of fireman lift shall be same as the corresponding dimensions for passenger lifts as specified in Table 1.

20.4.6.3. Factor of safety - The minimum factor of safety for any part of the lift shall not be less than five. Higher factor of safety for various parts shall be applicable in accordance with accepted standards.

20.4.6.4. Guide rails and buffers

Car and counter weight guide rails shall be of steel. Where the nature of processes carried on in the building give rise to acid fumes or corrosive substances the steel rails shall be treated for corrosion

Table - 1

Load

Car Inside

Lift well

Entrance

Persons

kg

A

B

C

D

E

4

272

1100

700

1900

1300

800

6

408

1100

1000

1900

1600

800

8

544

1300

1100

1900

1900

800

10

680

1350

1300

1900

2100

800

13

884

2000

1100

2500

1900

900

16

1088

2000

1300

2500

2100

1000

20

1360

2000

1550

2500

2400

1000

Note 1: The total headroom has been calculated on the basis of car height of 2.2 m

Note 2: In the case of manually- operated doors, clear entrance will be reduced by the amount of projection of handle on the landing door.

Note 3: Four-and six- passenger lifts are generally limited to a speed of 1 m/s.

Table 1 Dimensions of Passenger lifts (All in millimetres)

Table 2- Dimension of goods lifts (for speed upto 0.5 m/s)

All dimension in millimetres

Table 3 – Dimension of Hospital lifts (upto speed of 1.5 m/s )

All dimensions in millimetres

Table 4 – Dimension of Service lifts (upto speed of 0.5 m/s) All dimensions in millimetres

Table – 1A Recommended Dimensions of Pit, Overhead and Machine Room  for Passenger Lifts and Service Lifts.

Speed in m/s

Up to  0.70

> 0.70 ≤ 1.00

> 1.00 ≤ 1.00

> 1.50 ≤ 1.75

> 1.75 ≤ 2.00

> 2.00 ≤ 2.50

Pit depth

1 350

1 500

1 600

2 150

2 200

2 500

Overhead

4 200

4 250

4 800

4 800

5 200

5 400

Machine-room depth

D + 2 000

-

-

D + 2 500

-

-

Machine-room width

C + 1 000

-

C + 1 200

-

C + 1 500

-

Notes: 1. The total overhead dimension has been calculated on the basis of car height of 2.3m

  1. In case of  manually operated doors, clear entrance will e reduced by the amount of projection of handle  on the landing foor
  2.  
  3. All dimensions given above for lifts having centre opening power operated doors with counterweight at rear, are recommended dimensions primarily for architects and building planners. Any variations mutually agreed between the manufacturer and the purchaser are permitted. However, variation in:
    1. Car inside dimensions shall e within the maximum area limits specified in accordance with accepted standards..
    2. Entrance width on higher side is permitted
    3. Entrance width on lower side is permitted up to 100 mm subject to minimum of 700 mm.
    4.  Dimensions of pit depth and overhead may differ in practice as per individual manufacturer’s design depending upon load, speed and drive. Recommended dimensions for pit depth, overhead and machine-room for different lift speeds are given in Table 1A. However, the pit depth and overhead shall be such as to conform to the requirements of bottom clearance and top clearance in accordance with the accepted standards..

20.4.6.5. Car guide rails – For passenger and goods lifts having a contract speed of more than 0.5 m/s, the car guide rails shall have working surfaces machined. 

20.4.6.6. Counterweight guide rails – For passenger and goods lifts having a contract speed of more than 1.5 m/s, the counter weight guide rails shall have their working surfaces machined.

Guide rails shall be continuous throughout the entire length right from the bottom of the pit floor to the top most floor served plus additional length as may be required for operation of safety against overrun. They shall be provided with adequate brackets or equivalent fixing of such design and spacing that the rails shall not deflect more than 5mm under normal operations.

20.4.6.7. Buffers – Buffers of spring or oil shall be fitted under the lift car directly or on the pit floor with suitable concrete or steel foundation.  Oil resistant rubber buffers may be used with lifts having a contract speed not exceeding 0.25-m/s. Buffers shall be located symmetrically with reference to the vertical center line of the car frame with a tolerance of 50 mm. Spring or oil buffers shall be used with lifts having rated speed in excess of 0.25 m/s and up to and including 1.5m/s. Only oil buffers shall be used with lifts having rated speed in excess of 1.5 m/s. Wooden blocks suitably treated may also be used for service lifts for speeds up to 0.5 m/s.  

Table 2 Dimensions of goods lifts (for speeds up to o.5 m/s) All dimensions in mm

Load

Car inside

Lift well

Entrance

Kg

A

B

C

D

E

500

1100

1200

1900

1500

1100

1000

1400

1800

2300

2100

1600

1500

1700

2000

2600

2300

1700

2000

1700

2500

2600

2800

1700

2500

2000

2500

2900

2800

2000

3000

2000

3000

2900

3300

2000

4000

2500

3000

3400

3300

2500

5000

2500

3600

3400

3900

2500

Note 1: The width of the machine-room shall be equal to the lift well width ‘C’ subject to a minimum of 2500 mm.

Note 2: The total headroom has been calculated on the basis of a car height of 2.2m

Note 3: Clear entrance width ‘E’ is based on vertical lifting car-door and vertical bi-parting doors. For collapsible mid-bar doors the clear entrance width will get reduced by 200 mm or over depending on the lift design.

Table 3 Dimensions of hospital lifts (for speeds up to 1.5 m/s) (all dimensions in millimeters)

Load

Car inside

Lift well

Entrance

Persons

kg

A

B

C

D

E

15

1020

950

2400

1700

3000

800

20

1360

1300

2400

2200

3000

1200

26

1768

1600

2400

2350

3000

1200

Note 1: The total headroom has been calculated on the basis of a car height of 2.2m

Note 2: In case of manually operated doors, clear entrance will be reduced by the amount of projection of handle on the landing door.

Table 4 Dimensions of service lifts (for speeds upto 0.5 m/s) (All dimensions in millimeters)

Load

Car inside

Lift well

Entrance

Kg

A

B

H

C

D

E

100

700

700

800

1200

900

700

150

800

800

900

1300

1000

800

200

900

900

1000

1400

1100

900

250

1000

1000

1200

1500

1200

1000

Note 1: Entrance width ‘E’ is based on assumption of provision of vertical bi-parting doors (no car door is normally provided)

20.4.6.8. Stroke –The minimum stroke of oil buffers shall be such that the car or the counterweight on striking the buffers at 115 percent of the rated speed shall be brought to rest with an average retardation of not more that 10 m/s².

20.4.6.9. Retardation –Oil buffers shall develop an average retardation not in excess of 10 m/s² and shall develop no peak retardation greater than 25 m/s² having a duration exceeding 1/25 of a second with any load in the car from rated load to a minimum load of 68 kg when the buffers are struck with an initial speed of not more than 115 percent of the rated speed

The ratio of effective length to the least radius of gyration (L/R) of compression members of oil buffers shall not exceed 80.

20.4.7. Lifts wells and lift well enclosures

20.4.7.1. Lift wells

No equipment except that forming a part of the lift or necessary for its operation and maintenance shall be installed in the lift well. For this purpose, the main supply lines shall be deemed to be a part of the lift and the underground cable, if laid along the lift well shaft, shall be properly clamped to the wall.

Every counterweight shall travel in juxtaposition to its car in the same lift well.

It is undesirable that any room, passage or thoroughfare be permitted under any lift well. Where such conditions are unavoidable, spaces for other uses may be permitted under the lift well, with the prior approval of the Lift Inspectorate Authority and the following provisions shall be made:                

a) Spring or oil buffers shall be provided for lift car and counterweight;

b) The pit shall be sufficiently strong to withstand successfully the impact of the lift car with rated load or the impact the counterweight when either is descending at rated speed or at governor tripping speed; and

c) The car and the counterweight shall be provided with a governor-operated safety gear.

20.4.7.2. Lift well enclosures

Lift well enclosures shall be provided and shall extend on all sides from floor-to-floor or stair-to-stair. The enclosure shall be of sufficient mechanical strength. It shall be incumbent on part of the civil contractor to provide vertical walls in proper plumb.

The inner sides of the lift well enclosures facing any car entrance shall, as far as practicable form a smooth, continuous flush surface devoid of projections or recesses.

Note: This requirement may be met in existing lift wells by filling any recesses or spaces between projections or alternatively by covering them with suitable sheet material. If it is not possible to render flush any projection or tops of recesses, they should be beveled on the under side to an angle of 60º, from the horizontal by means of metal plates, cement rendering or other fire-resisting materials. Where a car-leveling device is operative with car door opening, such interior surfaces shall always form a smooth flush surface below each landing level for a depth to at least the depth of the car-leveling/one plus the distance through which the lift car may travel of its own momentum when the power is cut off.

Where an open lift well would increase the fire risk in a building, the lift well enclosure shall be of fire-resisting construction as specified in fire protection

Where wire grille or similar construction is used, the mesh or opening shall be not greater than 3 cm and the lift well enclosure shall be of sufficient strength to resist accidental impact by materials or trucks being moved in the vicinity.

Where the clearance between the inside of an open-type lift well enclosure and any moving or movable part of the lift equipment or apparatus is less than 5 cm, the openings in the enclosure shall be further protected by netting of square mesh of aperture not greater than one centimeter and of wire not smaller than one millimeter.

There shall be no opening in the lift well enclosure permitting access to the lift car by passing under the counterweight.

Sufficient space shall be provided between the guides for the car and the side walls of the lift well enclosure to allow safe and easy access to the parts of the safety fears for their maintenance and repairs.

In case of a completely enclosed lift well, a notice with the word ‘Lift’ may be placed outside of each landing door.

20.4.7.3. Indicator –Where lifts are installed in totally enclosed wells, position indicators are recommended to be provided at each floor; however, where position indicators are not provided, at least direction indicators or ‘In Use’ indicators shall be provided at each landing.

20.4.8. Lift pits

A lift pit shall be provided at the bottom of every lift.

Pits shall be soundly constructed and maintained in a dry and clean condition. Where necessary, provision shall be made for permanent drainage and where the pit exceeds 1. m, suitable descending arrangement shall be provided to reach the lift pit. And a suitable fixed ladder or other descending facility in the form of permanent brackets grouted in the wall extending to a height of 0.75 m, above the lowest floor level shall be provided. A light point with a switch shall also be provided for facility of maintenance and repair work.

20.4.9. Landing doors – Every lift shall, on each side from which there is access to a landing, be fitted with a landing door. Such door shall be fitted with efficient interlocking or other devices so as to secure that the door cannot be opened except when the lift car is at the landing and that the lift car cannot be moved away from the landing until the door is closed and locked. Where mid-bar collapsible doors are used for landing entrance, they shall not be power operated

Where landing doors are manually operated and no indicators are provided vision panels of similar construction as in 4.10.3 shall be provided.

No automatic fire door or shutter which operates by means of a fusible link or otherwise due to the action of heat shall be allowed in any landing, opening or the lift way enclosure of any lift, if such opening gives access to any exit from the building.

In the case of passenger lifts, for buildings above 15 m in height solid doors shall preferably be provided and in case of buildings above 24 m in height collapsible doors shall not be provided. Solid swing doors may also be used where sliding space is not available parallel to the entrance door.

20.4.10. Lift cars

Sliding doors (Non-collapsible) are recommended when power operation is used, but if space is limited, collapsible doors may be installed but they shall not be power operated.

Where the space between the car gate and inside the adjacent lift well enclosure exceeds 13 cm, car door of entrances shall be provided with means to prevent it from being opened except when the lift car is at a landing served by such car entrance.

Any vision panel in a car door shall be fire-resisting and shall be of safety wired or similar glass. The area between division bars or other support shall not exceed 0.1 m².  the bottom rail of a framed and glazed door shall be not less than 30 cm deep. Any projections on or recesses (including vision panels) in sliding car doors shall be kept to a minimum in order to avoid finger trapping between sliding parts of the door and any fixed part of the structure.

Where partitions are installed in lift cars for the purpose of restricting the platform net area for passenger use, they shall be permanently bolted, riveted or welded in place. Doors shall not be used for this purpose. Partition shall be so installed as to provide for approximately symmetrical loading.

Efficient automatic devices shall be provided and maintained in each lift whereby all power shall be cut-off from the motor before ca r or counterweight lands on the buffers.

The leveling difference between the car and the landing shall be within ± 4 cm where no leveling device is provided.

A suitable battery operated alarm system shall be installed inside the lift car so as to raise an alarm at a convenient place for getting assistance in case passengers are trapped inside the lift car.

Entrance of the lift car shall be at least 2.0 m in height. A roof, solid or perforated, capable of supporting two persons, that is, 2 x 68 kg shall be provided. Perforations shall be sufficiently close in mesh not exceeding 40 mm to provide reasonable protection against falling articles to any person traveling in the car. The floor shall be of a smooth and non-slip surface.

Each lift car shall be fitted with a light and light shall be left burning during the whole time the lift is available for use.

Where the lift car has solid enclosure and doors, provision shall be made for a fan and for adequate ventilation. To permit switching off the power supply to the lift without switching off the fan and light, a separate switch shall be provided for fan and light. Ventilation openings shall be provided in the enclosure walls above 1.8 m level and below 0.3 m level. Total area of openings shall not be less than 0.035 m² for each square metre of area of the car floor divided suitably between the top and the bottom levels.

Car doors when closed, shall guard the full opening except in the case of vertical opening car doors of goods lifts, which may be limited to 2 m and each door shall equipped with an electric contract which shall prevent the movement of the car and the circuit shall not be completed until the leading edge of the door Jamb or when the leading edges of the center opening doors are within 50 mm of contract of each other.

The car and the door, if power operated, shall be provided with sensitive reopening arrangements on the moving edges which are likely to come in contract with person(s) entering or coming out of the car. The operating mechanism for the car door shall operate with a force not exceeding 12.5 kg. Sliding car doors shall be guided at top and bottom. Means shall be provided to prevent all sliding car doors from jumping the tracks and suitable stops shall be provided to prevent the hanger carriage from leaving the end of the track.

20.4.11. Machine rooms and overhead structures- The lift machine, controller and all other apparatus and equipment of a lift installation, excepting such apparatus and equipment as function in the lift well or other positions, shall be placed in the machine room which shall be adequately lighted and rendered fire-proof and whether-proof.

The motor generators controlling the speed of multi-voltage or variable voltage machines, secondary sheaves, pulleys, governors, floor selecting equipment may be placed in a place other than the machine room, but such position shall be adequately lighted, ventilated and rendered fire-proof and whether-proof.

The machine room shall have sufficient floor area as will permit free access to all parts of the machines and equipment located therein for purposes of inspection. Maintenance or repair.

The room shall be kept closed, except to those who are concerned with the operation and maintenance of the equipment. When the electrical voltage exceeds 220 / 230 V dc, a danger notice plate shall be displayed permanently on the outside of the door and on or near the machinery. Where standby generator is provided, it is necessary to connect fireman lift to the standby generator. Depending upon the capacity of the standby generator one or more other lifts may also be connected to the supply. All lifts shall be provided with a standard cranking system to be used in case of power failure to bring the car nearest floor. A duplicate key should be made available near the machine room in a glass enclosure.

The machine room shall be equipped with an insulated portable hand lamp provided with flexible cord for examining the machinery.

If any machine room floor or platform does not extend to the enclosing walls, the open sides shall be provided with hand rails or otherwise suitably guarded.

The machine room shall be provided with a direct independent and convenient access from the top most landing with the access doors opening outwards.

The machine room shall not be used as a store room or for any purpose other than housing the lift machinery and its associated apparatus and equipment.

All machines, pulleys, over speed governors and similar units shall be so supported and held as to prevent any of these machines or parts thereof becoming loose or displaced affecting their safe working.

Machine room floor may be provided with a trap door, if necessary. The manhole should not be less than 50 x 50 cm.

The height of the machine room shall be sufficient to allow any portion of equipment to be accessible and removable for repair and replacement and shall be not less than 2 m clear from the floor or the platform of machine whichever is higher.

20.4.12. Housing of overhead pulleys – The penthouse or other space in which the overhead pulleys, over speed governors and similar machinery are housed shall have a clear height of at least 1.3 m and shall allow safe and convenient access and where practicable, have a substantial platform or floor and be provided with permanent and adequate artificial illumination.

20.4.13. Floor number board – The numbering of floors should conform to the system given in Fig. 1 (1 A, 1 B, 1 C, 1 D, 1 E, 1 F, 1 G, 1 H, 1 J and 1 K).

For detailed information regarding nomenclature of floors and storeys, reference may be made to accepted standards

20.4.14. Fire safety – Lifts shall also conform to the requirements specified in Section-23 on Fire protection.

20.5. Electrical wiring and apparatus

20.5.1. All electric supply lines and apparatus in connection with the lift installation shall be so constructed and shall be so installed, protected, worked and maintained that there may be no danger to persons there from. Installation of electric wiring shall conform to section-16.

No bare conductor shall be used any lift car as any cause danger to persons.

Suitable caution notice shall be affixed near every motor or other apparatus in which energy used is at a voltage exceeding 220 volts.

Circuits which supply current to the motor shall be included in any twin or multicore trailing cable used in connection with the control and safety devices.

20.5.2. A trailing cable which incorporates conductors for the control circuits shall be separate and distinct from that which incorporates lighting and signaling circuits in case of buildings less than 30 metres in height. In case of building more than 30 metres in height or where high speed  (1.52 m/s or more ) lifts are employed, use of single traveling cable for lighting and control circuits is permitted, provided that all conductors are insulated for the maximum voltage in the cable.

20.5.3. The cables used in lift installation shall conform to accepted standard.       

20.5.4. Earthing                      

The terminal for the earthings of the frame of the motor, the winding machine, the frame of the control panel, the cases and covers of the taper switch and similar electric appliances which normally carry the mains current shall be at least equivalent to a 10 mm diameter bolt, stud or screw. The cross-sectional area of copper earthings’ conductor shall be not smaller than half that of the largest current carrying conductor subject to an upper limit of 65 mm².

The terminal for the earthings of the metallic cases and covers of doors interlocks, door contacts, call and control buttons, stop buttons, car switches, limit switches, junction boxes and similar electrical fittings which normally carry only the control current shall be at least equivalent to a 5 mm brass

screw, such terminal being one specially provided for this purpose, and the earth conductor shall be at least equivalent to a 7 / 0.750mm conductor

The earthings conductor shall be secured to earthings terminal in accordance with Section-16, and also in conformity accepted standards code of ratio, with the latest provisions of Indian Electricity Rules.

The exposed metal parts of electrical apparatus installed on a lift car shall be sufficiently bonded and earthed.

Where screwed conduit screws into electrical fittings carrying control current making the case of cover electrically continuous with the conduct, the earthlings of the conduit may be considered to earth the fitting. Where flexible conduct is used for leading into a fitting, the fitting and such length of flexible conduit shall be effectively earthed.

One side of the secondary winding of bell transformers and their cases shall be earthed.

20.6. Number of lifts and capacity

Two basic considerations, namely, the quantity of service required and the quantity of services desired, determine the type of lifts to be provided in a particular building. Quantity of service gives the passenger handling capacity of the lifts during the peak periods and the quality of services is measured in terms of waiting time of passenger at various floors. Both these basic factors require proper study into the character of the building, extent and duration of peak, frequency of service required, type and method of control, type of landing doors, etc,.

20.6.1. Design considerations

The number of lifts, their capacity and speed required for a building is governed by such considerations as number of the floors to be served, number of passengers to be handled (see 6.1.3), floor area and floor heights. In large buildings, the provisions of a battery of lifts are advisable wherever feasible. Consideration should also be given to leaving space for additional lift installation to cater for future traffic development.

20.6.1.1. Occupant load – The number of persons with in any floor area or the occupant load shall be based on the actual number of occupants, but in no case less than those specified in Table 5.

Note: The occupant load of mezzanine floor should be taken into account for working out the occupancy for particular floor to which the mezzanine floor discharges its loads.

Fig.1Nomenclature of Floors and Storeys

Table 5 - Occupant load (clause 20.6)

Sl.No

Occupancy

Occupant load gross area* in m2/ person

i

Residential

12.5

ii

Educational

4

Iii

Institutional

15†

Iv

Assembly

a) Width fixed or loose and dance floor

b) without seating facilities including dinning rooms

 

0.6‡

1.5‡

v

Merchantile

a) Street floor and sales basement

b) upper sale floors

 

3

6

vi

Business and Industrial

10

Vii

Storage

30

Viii

Hazardous

10

Note: For the details of classification of occupancies, reference may be made to section on. Fire protection.

*The gross area shall mean plinth area or covered area.

†Occupant load in dormitory portions of homes for the aged, orphanages, insane asylums,  etc, where sleeping accommodation is provided, shall be calculated at not less than 7.5 m² gross area/person.

‡ The gross area shall include in addition to the main assembly room or space, any occupied connecting room or space in the storey or in the storeys above and below, where entrance is common to such rooms and spaces and they are available for use by the occupants of the assembly place. No deductions shall be made in the gross area for corridors, closets or other sub-divisions, the area shall include all space serving the particular assembly occupancy.          

20.6.1.2. Quantity of service – The quantity of service is a measure of the passenger handling capacity of a vertical transportation system. It is measured in terms of the total number of passengers handled during each five minute peak period of the day. A five-minute base period is used as this is the most practical time over which the traffic may be average. The passenger handling capacity (H) for different occupancies, expressed in percent of the estimated population that has to be handled in the building in the five-minute peak period, should be approximately as follows:

Class of occupancy

H (percent)

Diversified (mixed) office Occupancy

10-15

Single purpose office Occupancy

15-25

Residential

5

20.6.1.3. Quality of service – The quality of service is generally measured by the passenger waiting time at the various floors. The following shall be the guiding factor or determining this aspect:           

Quality of service or rating acceptable interval

20-25   Seconds

Excellent

30-35

Good

35-40

Fair

40-45

Poor

Over 45

Unsatisfactory

Note: For residential buildings, longer intervals up to 90 seconds should be permissible.

20.6.1.4. Car speed – The recommended car speed for the different types of lifts in different occupancies are given in Table 6.

20.6.1.5. Determination of handling capacity – The handling capacity is calculated by the following formula:

          300 X Q X 100

H = -----------------------

           T X P

Where

H = Handling capacity as the percentage of the peak population handled during 5 minute period

Q = Average number of passengers carried in a car,

T = Waiting interval in seconds, and

P =Total population to be handled during peak morning period (it is related to the area for which particular bank of lift serves)                                

The value of Q depends on the dimensions of the car. It may noted that the capacity during each trip and, therefore, for calculating H the value of Q is taken as 80 percent of the maximum capacity of the car.

The waiting interval, T is calculated by the following formula:

         Rt                                                                                

t = -----------

          n

Where

Rt  = Round trip time 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 the fresh passengers for the next trip; and

N = Number of lifts

Note: Rt is the sum of the time required in the following processes:

(a) Entry of passengers on the ground floor,(b) Exit of the passengers on each floor of discharge, (c) Door closing time before each time operation,(d) Door opening time on each discharging operations,(e) Acceleration periods,(f) Stopping and leveling periods, (g) Periods of full rated speeds between stops going up, and (h) Periods of the rated speeds between stops going down.

It is observed that the handling capacity is inversely proportional to waiting interval which in turn is proportional to Rt Reducing the Rt of a lift from 120 to 100 seconds increases its handling capacity by 20 percent

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, leveling and passenger movement.

These factors are given below

a) The most important factor in shortening the time consumed between the entry and exit of the passengers to the lift car is the correct design of the doors and the proper car width. It has been proved that the ideal door width is that of 100 cm and that of the ideal car width is approximately 200cm. Under these conditions, the car can comfortably hold four people, shoulder-to-shoulder in a straight line, permitting the two central located persons to make an exit without disturbing the rest of the passengers.

b) The utilization of center opening doors has been a definite factor in improving passengers transfer time, since when using this type of door the passengers, as a general rule, begin to move before the doors have completely opened. On the other hand, with a side opening door the passengers tend to wait until the door has completely opened before moving. The utilization of center opening door also favors the doors opening and closing time periods. Given the same door speed, the center opening door is much faster than the side opening type. It is beyond doubt that the center opening door represents an increase in transportation capacity in the operation of a lift. 

20.6.2. Positioning of lift – A through investigation should be made for assessing the most suitable position for lifts(s) while planning the building. It should take into account future expansions, if any.

Though each building has to be considered individually for purposes of location of lifts, factors influencing the locations of passenger and goods lifts are given in 20.6.2.

Table 6 Car speed for lifts in different occupancies.

Sl.No

Type of lift

Occupancy

Nos. of floors

Car speed

i

Passenger lift

Low and medium class flats (residential)

Office building, Hotels,

large flats (high)

Hospitals

Shops and departmental stores

-

 

4-5

6-12

13-20

-

0.5

 

0.5-0.75

0.75-1.5

above 1.5

2.25

ii

Goods lift

Normal †

Serving many floors

-

-

0.25-0.5

1

iii

Hospital bed lift

Short travel lifts in small Hospitals.

Normal 

Long travel lifts in general hospitals

-

-

-

-

0.25

0.5

1

The high speed is desirable especially where restaurant or other facilities are provided on the top floor as the traffic would at times demand a lift or lifts to be used entirely between the ground and the top floors.

† Slower speeds may be used for heavier loads.

The location of lifts may also conform to the travel distance requirements specified in section on Fire protection.

20.6.2.1. Arrangement of lifts –The lifts should be easily accessible from   all entrances to the building. For maximum efficiency, they should be grouped near the center of the building. It is preferably not to have all the lifts out in straight line and, if possible, not more than three lifts should be arranged in this manner. It has to be kept in mind that the corridor should be wide enough to allow sufficient space for waiting passengers as well as for through passengers.

In some cases when there are more than three lifts, the alcove arrangement is recommended  with this arrangement, the lift alcove lead off the main corridor so that there is no interference by traffic to other groups or to other parts of the ground floor. This arrangement permits the narrowest possible corridors and saves spaces on the upper floors. Walking distance to the individual lift is reduced and passenger standing in the center of the group can readily see all the lift doors and landing indicators. The ideal arrangement of the lifts depends upon the particular layout of the respective building and should be determined in every individual case. The recommended arrangements are given in Fig.2.

20.6.2.2. Passenger lifts

Low and medium class flats – Where a lift is arranged to serve two, three or four flats per floor, the lift may be placed adjoining a staircase, with the lift entrances serving direct on to the landings. Where the lift is to serve a considerable number of flats having access to balconies or corridors, it may be conveniently placed in a well ventilated tower adjoining the building.

Office buildings, hotels and high class flats –It is desirable to have at least a battery of two lifts at two or more convenient points of a building. If this is not possible, it is advisable to have at least two lifts side by side at the main entrance and one lift each at different sections of the building for inter-communication. When two lifts are installed side by side, the machine room shall be suitably planned with sufficient space for housing the machine equipment. The positioning of lifts side by side gives the following advantages: 

a) all machines and switchgear may be housed in one machine room.

b) the lifts can be inter-connected more conveniently from an installation point of view, and  

c) greater convenience in service owing to the    landing openings on each floor being adjacent.           

Shops and departmental stores – lifts in shops and stores should be situated so as to secure convenient and easy access at each floor.

Hospitals – It is convenient to place the passenger lifts near the staircases.

20.6.2.3. Goods lifts – The location of lifts in factories, warehouses and similar buildings should be planned to suit the progressive movement of goods throughout the buildings, having regard to the nature of processes carried out in the building, the position of loading platforms, railway sidings, etc. The placing of a lift in a fume or dust laden atmosphere or where it may be exposed to extreme temperatures, should be avoided wherever possible. Where it is impossible to avoid installing a lift in an adverse atmosphere, the electrical equipment should be of suitable design and construction to meet the conditions involved.

20.6.2.4. Hospital bed lifts – Hospital bed lifts should be situated conveniently near the ward and operating theater entrances. There shall be sufficient space near the landing door for easy movement of stretcher.

20.6.3. Shape and size of lift car – The shape and size of the passenger lift car bears a distinct relations to its efficiency as a medium of traffic handling. The width of the lift well entrance is, in

reality the basic element in the determination of the best proportion. The width of the car is determined by the width of the entrance and the depth of the car is regulated by the loading. Center opening doors are the most practicable and the most efficient entrance units for passenger lifts.

Fig 2 Recommended Arrangements for lifts

The detailed design considerations for different types and selection of the lifts shall be done in accordance with code of practice

20.6.4.   Positioning of machine room

The machine room should as far as possible, be placed immediately above the lift well as this has several advantages, such as reduced load on the building, lower capital cost of the lift, a smaller lift well for a given size lift car and reduced power consumption compared with a machine room in the basement, renewal of suspension ropes is less frequent and the cost of such renewals is less because shorter ropes are required and time taken for fitting them is less.

If a machine room on the lift well is impracticable for architectural or other reasons, the machine room may be placed below the lift well or in the basement, but guidance of a lift engineer should be followed on each instance, to minimize the disadvantage of its being so placed.

High-speed lifts with gearless machine should, in all cases, have machine room above the lift well.

Where the machine room occupies a prominent position on roof of a building, provision should be made for lighting protection in accordance with code of practice.

Wherever the machine room is placed it should be properly ventilated.

If located in the basement, it should be separated from the lift well by a separation wall.

20.6.5. Structural consideration

Lift well enclosures, lift pits, machine rooms and machine supports besides conforming to the essential requirements in 4, should from part of the building construction and comply with the lift manufacturer’s drawing.

20.6.6. Machine room – Floors shall be designed tom carry a load of not less than 500 kg / m² over the whole area and also any load which may be imposed there on by the equipment used in the machine room or by any reaction from any such equipment both during periods of normal operation and repair (see section 0-3 loads)

The total load on overhead beams shall be assumed as equal to all equipment resting on the beams plus twice the minimum load suspended from the beams.

The deflection of the overhead beams under the minimum static load calculated shall not exceed 1 / 1500 of the span.

The beams supporting the slab which carries lift machinery carry the entire weight and as such shall be designed to take these loads. In addition, the beam at all other floor levels which correspond to the beams at machine room floor shall also be made stronger to take the reaction from the guides when the lift is made to stop consequent on the breaking of the wire ropes or the application of the safety device.

Suitable lifting beams immediately below the machine room ceiling may be provided for carrying tackle to facilitate lifting of any heavy part of a heavy lift (say about 1/500 kg  capacity); and capacities below that, suspension hooks may be provided.

In the case of large lift installations, the roof of the machine room also should be designed top take up the pulley which could be used for lifting up parts of the lift machinery for inspection and repair.

The equivalent dead loads imposed upon the building by the lift installations should be shown on the lift manufacturer’s drawing so that the architect / engineer may make provisions accordingly.

20.6.7. Access to Machine Room and Lift Pits

Access to a machine room above a lift well may be either from the roof or by an internal staircase.

Access between a secondary floor and a machine room may be by ladder. Where a machine room entrance is less than 1.5 m above or below the adjacent floor or roof surfaces, a substantial permanently attached ladder may be used. Ladders shall be fixed at least 15 cm clear of any wall, beam or obstruction and shall extend at least to the landing level. Above the landing level and for a height of at least 1.15 m, either the ladder stringers shall be extended or suitable hand grips shall be provided.

Where the machine room entrance is 1.5 m or more, above or below the adjacent floor or roof surface, access shall be provided by means of stairs in accordance with the requirements..

The angle of inclination of the stair shall not exceed 50º from the horizontal and the clear width of the stair shall be not less than 60 cm. 

The tread shall have a non-slip surface which shall be not less than 15 cm wide for open stair construction and not less than 20 cm wide for closed stair construction.

The riser of the stair shall not exceed 25 cm.

A hand rail shall be provided on the outer stringer of all stairways fixed at a convenient height, but not less than 50 cm high measured vertically from the nosing, and not less than one metre high on landings and platforms.  Such hand rail shall have at least 5 cm clearance between nearest permanent object at the corresponding side of the stair.

Headroom clearance of not less than 2 m measured from the nosing of the stairway shall be provided on every stairway.

Heights of stairs over 5m in length shall be provided with intermediate landings.

Note: Where compliance with any of the requirements specified in 20.6.7.1 to 20.6.7.3 is impracticable, applications for variation shall be made to the Authority, who may, vary such requirements.

Access to a machine room in a basement may be provided from a corridor.

Access to a machine room via the lift well shall be prohibited.

The lift pit should be capable of being examined by a separate access. In the case of a battery of two lifts, it is possible to examine the lift pit through the adjoining one.

20.6.8. Fire protection – To prevent fire from spreading by means of the lift well, lift well enclosures shall conform to the requirements given in section-23 Fire Protection. The machine room should be constructed of a suitable grade of fire-resisting material and precautions should be taken to minimize spread of fire from the machine room into the lift well.

20.6.9. Quiet operation – Every precaution should be taken with passenger lifts to ensure quiet operation of the lift doors and machinery. The insulating of the lift machine and any motor generator from the floor by rubber cushions, prevents transmission of most of the noise

20.6.10. Supply cables and switches – Each lift should be provided with a main switch or circuit breaker of a capacity determined by the lift manufacturer and the incoming supply cable should terminate in this switch. For a single lift, this switch should be fixed adjacent to the machine room entrance. In a machine room common to more than one lift, each main switch should be conveniently situated with respect to the lift it controls. Switches and fuses (which may form part of a distribution switchboard) should be provided for isolating the supply cables to the machine room.

Where a supply cable serves more than one lift, a diversity factor may be used for determination of conductor size. The actual diversity factor adopted should be decided by the lift manufacturer. 

20.6.11. Control system

The control systems that may be adopted are:

(a) attend and dual control,  (b) automatic push button control,(c) collective control,(d) single push button collective control,(e) down collective control,(f) directive collective control for one car,(g) directive collective control for two to three cars, and (h) group supervisory control.

20.6.12. Features of control systems

20.6.12.1. Car preference – Some times it is necessary to give a special personal service or a house service. When this type of service is required, it should be specified as car preference. The transfer from normal passenger control to a car preference is by a key operated switch in the car only and the doors remain open until a car call is registered for a floor destination. All landing calls are bypassed and car

position indicators on the landings for this lift are not illuminated. The removal of the key when the special operation is completed restores the control to normal service

20.6.12.2. Landing calls automatic bypass – For collective operation automatic bypassing of landing calls can be provided. This device will bypass landing calls when a car is fully loaded but the calls are not cancelled.

20.6.12.3. Motor generator shut down – lifts controlled by variable voltage systems automatically shut down when subject to an overriding control which puts them out of service under certain conditions; for example, no demand for lift service. They are automatically put back into service as required.

20.6.12.4. Basement service – For lifts with collective control when service is required below the first floor, to a basement(s), the lift maker shall be aware of the service required.

20.6.12.5. Hospital service – This requires car preference as specified in 20.6. Otherwise such lifts can have the same control system as for normal passenger lifts, the choice depending on the number of floors served, service required and the number of lifts.

20.6.12.6. Manually operated in copinal doors (without closures) - A door open alarm should be provided to draw attention to a car or landing door which has been left open.

20.6.12.7. Automatically power closed doors-For passenger operation when the car arrives at a landing, the doors will automatically open and then close after lapse of a time interval. This time interval can be overruled by the use of a car push button to give instant door closing. An open door push button is provided in the car to reverse closing motion of the doors or hold them open.

20.6.12.8. Controlled power closed doors – When there are conditions that particularly affect the safety of passengers, the closing of the doors should only be made by the continuous pressure of push buttons in the car or on landings.

20.6.12.9. Safe operation of doors – The safety of passengers shall be ensured.

As all lift cars are illuminated when in service, it is recommended that this illumination be used to signal the arrival of a car at a landing in preference to special signals such as LIFT HERE signs since signal lamp can fail when the lift is still operating satisfactorily.

20.6.12.10. Service switches – When switches are provided to take car out of service, that is because the remaining cars in the group can cater for the required passenger traffic, it is essential that such switches should not stop the foreman’s control from being operative in the event of the lift being designated as a fireman’s lift.

20.6.12.11. Fire switch – When required fire switch shall be provided, the function of which is to enable the fire authority to take over complete control of one or more lifts in an installation.

20.6.12.12. Push buttons and signals – Every push buttons and signals shall be clearly marked so that its function is clearly understood by all passengers.

20.7. Testing

20.7.1. Test on site – The lift shall pass the following tests when carried out at site and before it is put into normal service. The necessary test weights and instruments shall be provided by the lift manufacturer and the electric power at the declared voltage (and frequently) required for adjusting and testing shall be supplied by the purchaser:

a) Test to determine that the insulation resistance between power and control lines and earth not less than 0.5 MW Volts when measured with a dc voltage of 500 volts. The test should be carried out with the conductors so connected together as to ensure that all parts of every circuit are simultaneously tested.

Note: The dampness of the building may prevent a reading of 0.5 MW from being obtained, in which event the lift may be provisionally accepted by the purchaser with an insulation resistance of 0.25 MW and re-tested before being finally accepted.

b) Test to determine that the earthing of all conduct switch casings and similar metal work is continuous and of low resistance. Test should be made from all terminal points by means of a substantial current to ensure that the resistance of earth path is sufficiently low to enable fuses or circuits to operate under faulty conditions.

c) Test to determine that the lift car raises and lowers rated load.

d) Test to determine that the lift car atleast achieves the contract speed.

e) Test to determine that the safety gear stops the lift car with rated load. Over speed tests shall be made with ropes attached and all electric apparatus operative except the over speed switch on the governor. The stopping distance of the lift car is the actual slide as observed from the marking on guides.

Note: The safety gear of the lift having AC motor driven machine may be tested by manually tripping the governor where the speed attained by a loaded lift car descending, with brake released, is sufficient to operate the governor.

20.8. Running and maintenance

The lift installation should receive regular cleaning, lubrication, adjustment and adequate servicing by authorized competent persons at such intervals as the type of equipment and frequency of service demand. 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 log book to record all items relating to general servicing and inspection is recommended for all lifts. It is essential that the electrical circuit diagram of the lift with the sequence of operation of different components and parts should be kept readily available for the persons responsible for the maintenance and replacement where necessary.

Particular attention may be directed for thorough periodical examination of wire ropes when in service. Attention should also be directed to the thorough examination of the groove of drums, sheaves and pulleys when installing a new rope. A groove deepened by rope wear is liable to lead to early failure of a new rope unless the groove is turned.

Any accident arising out of operation of maintenance of the lifts should be duly reported to the Authority in accordance with the rules laid down. A notice may be put in the machine room to this effect.

20.9. ESCALATORS

Escalators are deemed essential where the movement of people, in large numbers at a controlled rate in the minimum of space, is involved, for example, railway stations, airports, etc. in exhibitions, big departmental stores and the like; escalators encourage people to circulate freely and conveniently.

As the escalators operate at a constant speed, serve only two levels and have a known maximum capacity, the traffic study is rather easy. Provided the population to be handled in a given time is known, it is easy to predict the rate at which the population can be handled.

For normal peak periods, the recommended handling capacities for design purposes should be taken as 3 200 to 6400 persons per hour depending upon the width of the escalator.

20.9.1. Essential requirements

Angle of inclination shall not be in excess of 30º from the horizontal excepting that with an escalator having a vertical rise not exceeding 6 m an angle to 35º may be permitted.

The width between balustrades shall be measured on the incline up to a point 68.5 cm vertically above the nose line of the steps, and shall not be less than the width of the step. It shall not exceed the width of the step by more than 33 cm with a maximum of 16.5 cm on either side of the escalator.

Escalators shall be provided on each side with solid balustrades. On the step side the balustrades shall be smooth and substantially flush except for protective moulding parallel to the run of the steps and properly beveled vertical mouldings projecting not more than 6.5 mm, that cover joints of panels.

There shall be no abrupt changes in the width between the balustrades on the two sides of the escalator. Where a change in width is unavoidable, such change shall not exceed 8 percent of the greatest width. In changing the direction of the balustrades resulting from a reduction in width the

maximum allowable angle of change in balustrades shall not exceed 15 degrees from the line of the escalator travel

The clearance on either side of the steps between the steps and the adjacent skirt guard shall be not more than 5 mm and the sum of the clearances on both sides shall be not more than 6 mm.

A solid guard shall be provided in the intersecting angle of the outside balustrade (deck board) and the ceiling or soffit except where the intersection of the outside balustrade (deck board) and the ceiling or soffit is more than 60 cm from the centerline of the handrail. The vertical face of the guard shall project at least 36 cm horizontally from the apex of the angle.

20.9.2. Handrails

Each balustrade shall be provided with a handrail moving in the same direction and at substantially the same direction and at substantially the same speed as the steps.

Each moving handrail shall extend at normal handrail height not less than 30 cm beyond the line of points of complete teeth at the upper and lower landings.

Hand of finger guards shall be provided at the point where the handrails enter the balustrade.

The horizontal distance between the center lines of two handrails, measured on the incline, shall not exceed the width between the balustrades by more than 15 cm, with a maximum of 7.5 cm on either side of the escalator.

20.9.3. Steps tread

The depth of any step tread in the direction of travel shall not be less than 40 cm and the rise between shall not more than 22 cm. The width of step tread shall be more than 40 cm less than 102 cm. 

The maximum clearance between step treads on the horizontal run shall be 4mm

The tread surface of each step shall be slotted in a direction parallel to the travel of the steps. Each slot shall be not more than 6.5 mm  wide and less than 9.5 mm deep; and the distance from center to center of adjoining slots shall be not more than 9.5 mm.

20.9.4. Landing –Landing shall be made out of antislip material.

20.9.5. Comb plates –There shall be a combplate at the entrance and at the exit of every escalator. The combplate teeth shall be meshed with and set into the slots in the tread surface so that the points of the teeth are always below the upper surface of the treads. Completes shall be adjustable vertically

20.9.6. Trusses or girders –The truss or girder shall be designed to safety sustain the steps and running gear in operation. In the event of failure of the track system it shall retain the running gear in its guides.

20.9.7. Step wheel tracks –This shall be designed to prevent displacement of steps and running gear if a step chain breaks.

20.9.8. Rated load –The rated load in kilogram on an escalator shall be computed by the following formula:

Rated load = 2.7 W A

Where

W = width in cm between the balustrades, and

A = horizontal distance between the upper and lower combplate teeth in meters.

The rate speed shall not be more than 38 meters per minute

20.9.10. Design factor of safety –The factor of safety based on static load shall be at least the following:

a) For trusses and all structural members including tracks-five

b) For driving machine parts:

  1) Where made of steel or bronze  -eight,  

  2) Where made of cast iron and other materials   -ten,

c) For power transmission members –ten.

Step chain composed of cast-steel links which, if thoroughly annealed, shall be permitted with a factor of safety of at least twenty.

20.9.11. Driving machine, motor and brake - The driving machine shall be connected to the main drive shaft by toothed gearing, a coupling, or a chain.

An electric motor shall not drive more than one escalator.

Each escalator shall be provided with an electrically released, mechanically applied brake capable of stopping the up or down traveling escalator with any load up to rated load. This brake shall be located either on the driving machine or on the main drive shaft.

Where a chain is used to connect the driving machine to the main drive shaft, a brake shall be provided on this shaft, it is not required that this brake be of the electrically released type if an electrically released brake is provided on the driving machine

20.9.12.. Speed governor – A speed governor shall be provided, the operation of which shall cause the interruption of power to the driving machine should the speed of the steps exceed a predetermined value which shall be not more than 40 percent above the rated speed.

Note: The over speed governor is not required where a low slip alternating current squirrel cage induction motor is used and the motor is directly connected to the driving machine.

For operation and safety devices, electrical work, precautions and tests reference may be made to good practice.

20.10. Acceptance of tender and subsequent procedure

20.10.1. General - The procedure indicated below particularly relates to the most usual case, where the lift maker is a sub-contractor

20.10.2. Order – The main contractor is instructed to place an order with the selected lift maker. If alternative schemes have been offered, the order should clearly indicate which has been accepted.

20.10.3. Programme - As noted in 10.5 the programme should have been indicated as accurately as possible at the time o enquiry. At the time of order, the programme for manufacture and installation of the lift should be agreed.

The programme should cover each lift separately including dates such as:

(a) The order date, (b) The date when the lift site will be ready (c) The date for provision of lift electricity supplies and (d) The lift completion date.

The period between order and delivery of material falls into two stages: first the finalizing of details and secondly the actual production of the equipment when depends on the first stage. Within the first stage, other dates may need to be considered, such as: (a) All relevant building information available (b) Submission of lift maker’s drawings (c) Approval of drawings and (d) Final selection of finishes.

Information relevant to programming the site work can be found in other clauses of this Section, such as in 20.12 and 20.13.

20.10.4. Drawings – Following order, the lift maker should supply drawings showing builder’s work required, together with point loadings. To enable these to be prepared, the purchaser’s representative should furnish the relevant detail building drawings.

20.10.5. Approval of Drawings – The purchaser’s representative should give written approval of the drawings (after modification if necessary), at the same time asking for such additional copies (up to five of each drawing) as he requires for distribution to other parties concerned.

20.10.6. Selection of Finishes – Where the contact provides for the purchaser’s choice of decorative finishes, colours, etc, the decisions should be communicated by the purchaser’s representative as early as possible, and preferably not later than the time of approval of drawings

20.10.7. Electricity Supplies to Lift – Operation of the machine under power is required from a comparatively early stage of installation for the most efficient working, and supplies should be furnished accordingly. Whilst temporary supplies may be sufficient for erection purposes, final testing and setting up can only be carried out with the permanent supplies connected. For this reason the timely provision of the permanent supplies is important.

20.11. Co-ordination at site

20.11.1. Preparatory Work on site – It is customary for the lift maker to make periodic visits to the site before his starting date to check progress on the lift well construction and discuss relevant matters with the contractor. The lift maker should assure himself that all building work has been completed in accordance with his requirements.

Immediately, before the time for lift erection to commence the lift maker should check that site conditions are fit to permit erection to proceed.

Building work to be completed before lift erection starts includes the following:

a) Pit lift well and machine room complete and weather tight. Pit dry and watertight including tanking if necessary and clear of rubbish

Note: In certain systems building and buildings of over 10 floors, it may be necessary by prior agreement to start erection before the top portion of the lift well has been constructed, in which case the general contractor should temporarily deck out and waterproof.

b) Preparation for lift fixings in pit, lift well and machine room complete. If built-in wall inserts are used, these should be placed accurately and slots cleared of any seepage of concrete.

c) Steel work items finally grouted or otherwise fixed in position after checking for correct position by the lift maker (for example lift well trimmers and machine beams).

d) Scaffolding in position, as arranged with the lift maker, lift well etc. properly fenced and guarded in accordance with current regulation

e) Entrance preparations completed, including preparations for door frames, push boxes and indicators. In many cases, progress can be facilitated by omitting the front walls of the lift well until the lift car, doors, etc. are installed.

f) Datum line (in elevation) established at each floor to enable the lift maker to set metal sills and frames in relation to finished floor levels.

20.11.2. Delivery of Material

 The lift maker should advise the contractor when equipment is ready for dispatch, so that the contractor can make arrangements on site to receive and unload with appropriate hoisting tackle, slings and supports, as near as possible to the lift well.

20.11.3. Storage – Adequate provision should be make by the building contractor for storing protecting and preserving against loss, deterioration or damage, all material on the site. Attention is drawn to the adverse affect of damp conditions on electrical equipment and on steel wire ropes.

20.11.4. Site Meetings – For the successful progress of the work, full co-operation among all parties is essential. In large sites, regular meetings of such parties are beneficial. Programmes for the constructional work in that part of the building containing the lift should be made in consultation among all parties concerned.

20.11.5. Service of Other Trades – The lift erector will require the services of joiners, bricklayers and other trades as the work proceeds, and it is essential that the lift erector should give due notice to the building contractor of the demands to be made on other trades, so that he can plan accordingly.

20.11.6. Scaffolding, Fencing etc. -  Scaffolding timbers, rollers and similar items required for the unloading and erection of the lift, and also for the proper guarding and close fencing of the lift well should be provided, erected and maintained by the building contractor.

The lift well should not be used as a means of disposal for rubbish from the upper floors. Such practice is dangerous.

The lift well should be handed over to the lift contractor complete, and no other trades should be allowed to work above or below during the whole time of erection of the lift, except by arrangement with the lift contractor.

The lift well should be handed over to the lift contractor complete, and no other trades should be allowed to work above or below during the whole time of erection of the lift, except by arrangement with the lift contractor.

20.11.7. System Building Sites – If the building programme allows insufficient time for lift erection in conventional fashion after the well is completely built special procedures are needed. This applies particularly to industrialized and multi-storey buildings.

Methods differ in detail. In most cases however the building contactor’s crane is used to lower and position pre-assembled batches of lift equipment into the progressively rising top of the lift well.

The building contractor should provide a suitable portable cover to the completed portion of the lift well in order to protect the lift erectors working below against the weather and falling objects.

When the top of the well as been reached it is normal to cap it immediately with a precast  load bearing floor slab on to which is lowered the pre-assembled machine room equipment. It then remains for the building contractor to complete and weatherproof the machine room as swiftly as possible.

On all such projects as these the closet co-operation between the building contractor and the lift maker is essential.

20.11.8. Connecting to Power Supply – The lift maker should give prior warning to the building contractor of the date the power supply to the lift is required, so that suitable arrangements for connection can be made.

20.12. Procedure following test, including inspection and maintenance

20.12.1. Acceptance – The purchase should make timely arrangements for accepting the lift on completion of test, and for insurance cover. Special arrangements are necessary if there is to e at interval before the lift goes into normal service

20.13.2. Guarantee and Servicing - Any guarantee provided by the lift maker should be conditional upon the lift receiving regular and adequate servicing, and should cover the free replacement of parts which prove defective through reasons of fault, materials or workmanship in the guarantee period, which is generally twelve months.

To ensure the continuance of satisfactory and safe operation, the purchaser (or building occupier) should arrange for the completed lift to receive regular servicing by competent persons at such intervals as the type of equipment and intensity of operation demand. Such service can be secured under a service contract. It is desirable and normal for the lift maker to be entrusted with the servicing during the guarantee period of a new lift.

The scope of a service contract may be extended to cover not only regular servicing, but also intermediate service calls, repairs and replacement of worn parts.

The building owner should co-operate with the service engineer, and should ensure that the equipment is properly used, and that unauthorized persons are not permitted to enter the lift well or machine rooms.

Particularly attention should be paid to methods of ensuring that lifts are not overloaded when they are used in connection with furniture and equipment removals, and internal redecoration and other similar activities, which may be undertaken within the building.

20.12.3. Statutory Examinations - Lifts in certain premises are required by statutory regulations to be examined at intervals, as specified by the Lift Act, by a competent person, who is required to report on a prescribed form. Such reports should normally be kept in a register.

Statutory examinations are not a substitute for servicing; the provision of statutory reports may be specially included in a service contract or may be arranged separately.

20.12.4. Lift not in immediate use (shut down maintenance) – When conditions do not permit a lift to be taken to normal service immediately following completion and acceptance, it should be immobilized. The main contractor should take effective precautions against damage especially to finishes, or damage to equipment from dampness and builder’s debris, until such time as the lift is required.

A separate service contract should be made with the lift maker to make regular visits during this period, do inspect, lubricate and report on the condition of the lift.

A date should also be agreed with the lift maker from which his guarantee period will commence.

20.12.5. Temporary Use of Lifts – If the purchaser intends to permit temporary use of a lift by some other party, such as the building contractor, before taking it into normal service, so that it is not immobilized, then the responsibilities of those concerned should be clearly defined and agreed. In addition to the precautions, temporary insurance cover should be arranged.

If temporary use of lifts is envisaged, it should preferably be given consideration at an early stage, having regard to the conditions under which it is likely to take place.

20.12.6. Cleaning Down – Acceptance following test should include checking the condition o decorative finishes, before the lift maker leaves the site.

After a shut down (or temporary service) period, the lift may require a further general cleaning down immediately before taking into normal service. The lift maker should be instructed accordingly to undertake this work and if any accidental damage has occurred to repair this at the same time. Both these items should be the subject of extra costs.

Annexure 20-A.1.

LIST OF STANDARDS

The following list records those standards which are accepted standards in the fulfillment of the requirements of the code. The latest version of a standard shall be adopted at the time of enforcement of the code. The standards listed may be used by the Authority as a guide in conformance with the requirements of the referred clauses in the Code.

IS No.

Title

14671-1999

Code of practice for installation and maintenance of hydraulic lifts

14665 (Part I)-2000

Electric traction lifts: Guidelines for outline dimensions of passenger, goods, service and hospital lifts

14665 (Part 3/Sec. 1 & 2)-2000

Safety rules, Section 1 Passenger and goods lifts, Section 2 Service lifts

14665 (Part 4/Sec. 1 to 9)-2001

Components, Section 1 Lift Buffers, Section 2 Lift guide rails and guide shoes, Section 3 Lift carframe, car, counterweight and suspension, Section 4 Lift safety gears and governors, Section 5 Lift retiring cam, Section 6 Lift doors and locking devices and contacts, Section 7 Lift machines and brakes, Section 8 Lift wire ropes, Section 9 Controller and operating devices

14665 (Part 4/Sec.1 to 9) - 2001

Electric traction lifts: Components, Section 1 Lift Buffers, Section 2 Lift guide rails and guide shoes, Section 3 Lift carframe, car, counterweight and suspension, Section 4 Lift safety gears and governors, Section 5 Lift retiring cam, Section 6 Lift doors and locking devices and contacts, Section 7 Lift machines and brakes, Section 8 Lift wire ropes, Section 9 Controller and operating devices

14665 (Part 3/Sec.1 & 2)-2000

Electric traction lifts: Part 3 safety rules, Section 1 Passenger and goods lifts, Section 2 service lifts

14665 (Part 2/ Sec.1 & 2)-2000

Electric traction lifts: Part 2  code of practice for installation, operation and maintenance, Section 1 Passenger and goods lifts, Section 2 service lifts

962-1989

Code of practice for architectural and building drawings (second revision)

2309-1989

Code of practice for the protection of buildings and allied structures against lightning (second revision)

1950-1962

Code of practice for sound insulation of non-industrial buildings

14665 (Part 3/ Sec. 1 & 2) – 2000

Electric traction lifts: Part 3 Safety rules – Section 1 Passenger and goods lifts, Section 2 service lifts

3043-1987

Code of practice for earthing

4591-1968

Code of practice for installation and maintenance of escalators

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