ELEVATOR SERVICE INDUSTRY
Product and service are closely related elements of Marketing Strategy. Depending on the nature of the Product offering and needs of firm composing the target markets, after Sales Services may be indispensable in winning and holding customers. In a strategic sense service can be defined as an activity undertaken for the express purpose of aiding customers while this is a rather nebulous (Not distinct) statement, it does exclude such activities as frequent sales calls. Local availability of inventories, and warranties which of course aid customers but are seldom undertaken expressly for that purpose. What does fit in to this concept are such activities as Pres-sale engineering studies, technical consultation, and Performance testing, as well as such conventional Post-Sale aid as financing, operator training, installation and maintenance. Despite the high cost and the abuse, which so often accompany it, customer service is core element.
In the strategic plan, after sales service is very important and strategic part of capital Equipment’s sale. If customer’s ultimate customer don’t get timely preventive or break down service then entire capital investment can go in to Drain. Basically in Elevator Equipment industry buyer is not user and ultimate users are real buyers of Elevator Equipment. So any dis-satisfaction from ultimate customer have double effect on seller.
The last decades have seen a profound change in the composition of the economy. In all countries, the commercial service sector is now at least double the size of the manufacturing sector in terms of GDP, three times the size if you include social and public services (e.g. health, education) in that figure. That trend is set to continue. For the Internal Market to function efficiently it is essential that the regulatory framework develops in tandem with these changes.
- History of Elevator Industry:
Experts believe that as early as 2000 B.C, the Egyptians used hoists of some type to build the pyramid is over 500 feet tall and has many building blocks weighting more than 200,000 pounds. In Rome, about 80 A.D, wild animals and gladiators rode crude Elevators up to the arena level of the Roman Coliseum. The oldest known hoisting machine till recently in existence is in the Abbey of Mount St.Michel on the French seacoast. Installed in 1203, it used the large tread wheel with a donkey supplying the walking power.
In the middle of the 17’^ century, a resident of Paris invented the “Flying Chair”, which was cranked up and down by a servant. A hoist way was used with this device, and a cage was raised and lowered by a rope passing around to a drum and down to ahead counterweight. Similar hoists are said to have been installed in Windsor Castle for Queen Anne in 1713. Over the next few centuries, various hoist and lifts were developed to carry people and freight. All of them used muscle power for hoisting Devices. Power hoisting devices was considered only after the invention of the steam-powered elevator to lift coal up the mineshafts.
In 1835, a steam-powered elevator called the “teagle” carried freight in an English Factory. In 1845, Sir William Thompson developed the first hydraulic elevators appeared in 1850 as steam-operated platform hoists for freight service. The one clanger in any kind of vertical transportation developed so far was obvious. Because whether a hoist, pulley, or block and tackle was used, if the rope broke, well you can imagine the results.
Things changed only after Elisha Graves Otis invented the safety hoist in 1852. Due to scarcity of land, elevators fall under “Must Utility”. All over the world elevator is Key Utility in any medium to high-rise building. Elevator Industry in all over the world by 5, 00,000 to 5, 50,000 lakhs elevators per year. Present Status: Elevator is part of building infrastructure. As per statistics of lEEMA (Indian Electrical and Electronics Manufacturers Association) Total Elevator selling by organized and unorganized sector was 6800 elevators in 2003 and 2004 Forecast for Total Market is 8900 Elevators. Elevator Industry is growing at 8% to 10% globally per annum. In India elevator industry is growing at 15 to 18 % per annum and Market is very competitive. Here major factor is competition from unorganized players. Maharashtra’s share in to total 8900 forecast of elevator is 2500 Units and Pune Region share in total Maharashtra in terms of elevator unit is 800 to 850 elevators. (Ref.www.elevatonworld.com)
- Classification of Elevators:
- Geared Traction. (Passenger) Light.
- Gearless Traction. (Passenger) Heavy.
Railway Stations, Services Terminals. Air Port, Metro
Freight, Hospitals. Commercial Complex.
Classifications of Elevator users:
- A) Residential users.
- B) Commercial complex.
- C) Hotel industry.
- E) Shopping malls
- F) Industrials users for material handling.
- G) Institutional clients like govt. building, educational buildings etc.
- Elevator System Design.
Good elevator system design is critical to a multi-storied building. Planning of elevator system must therefore design programs, within both new construction and refurbishment schemes. The quality of vertical transport is vital to building circulation and therefore has a profound effect on human response to a building itself. If it is correct, acceptability, reputation and a sound investment are assured. If it is incorrect, it causes disadvantages from which escapes is difficult and usually expensive.
- Typical Arrival Pattern- Commercial
Building elevator system must be configured to match the expected traffic requirement, both present and future. This means that accuracy in predicting expected building population and how and when it will move is critical, for it is on this principle that fundamental elevator system design decision must be based. Key decisions, such as the number of elevator shafts, cannot be easily modified in the later stage of building development.
Predicting population flow and patterns is pattern a difficult and uncertain task, needing a unique expertise. Using data predictions in the process of producing an optimum elevator system design, or the art of elevating, as it is known, is also a specialist’s task.
Knowledge and experience are essential to get things right the first time.
- Key Design Considerations:
There are many variables that affect elevator system design.
However, the ones to be specified are;
- Number of floor to be served,
- Floor to floor distance,
- Population of each floor,
- Location of building,
- Specialist services within building,
- Type of building occupancy.
- Maximum peak demand in passengers per five-minute period.
To meet the elevator system specification, there are many design features that an elevator manufacturer can vary. Of these, the principal ones are:
- Elevator speed
- Elevator car dimensions
- Number of elevators
- Elevator design characters tics. (e.g. Entrances and control system).
Although design estimates can be made manually, with many variables to be included in the overall process, on larger projects it requires the use of computers techniques to obtain optimum solutions. This applies particularly to complex design.
- Basic Elevator Planning:
Basic Design Parameters:
There are numerous parameters, which can be used to judge elevator system performance. The principal one is based on quality of service. Quality of service is related fundamentally to the time interval a passenger hast to wait for an elevator car and how quickly the system transports that passenger to a desired destination. To quantify the concept a standard definition is used. Quality of service (or interval) is the expected average interval (in seconds) between the arrivals of elevators at the main floor.
In basic terms, this is the round trip time of one elevator divided by the number of elevators in a group. The required handling capacity, or quantity of service of a system is expressed, in elevator industry design terms, as a function of the expected building population. It is stated in units of the percentage of building’s population to be transported within a five-minute period.
- Building Types:
The guidelines below indicate the key design features for particular building types. Although some qualitative and quantitative advice is given, it should always be remembered that there is no substitute for accurate estimation of traffic patterns. Average values are quoted for guidance. However, true estimation for an particular building, including local influences, such as the location of transport terminals or stations, can alter these significantly.
Maximum traffic usually occurs just before the start of working hours and is known as ‘up morning peak’ in elevator industry jargon. Office buildings with single (unified) tenancy usually provide heavier peak flows than those with multiple (diversified) tendencies. If more detail estimates cannot be made, the following handling capacity requirements should be used as a basis for design to meet up morning peak.
- Unified tenancy -15 to 25 percent of the total building population entering in a five-minute period,
- Diversified tenancy -10 to 15 percent of the total building population entering in a five-minute period.
There will be other peaks in elevator system usage, such as at lunchtime and in the evening when people leave. Peaks can also be caused by the location of basement garages, conference rooms, restaurants and similar mass use facilities. The effect of these must be taken into account individually.
Designing for a quality of service is very much dependent on the preferences and need of the owner or occupant of a building.
A general guide to the acceptability of service intervals can be summarized as follows.
- Average interval 20-25 seconds-excellent.
- Average interval 35-40 seconds-fair.
- Average interval 45 seconds- poor.
A large prestigious office building must often meet exceptional interflow traffic demands, which have to be considered in planning. These demands can often be very complex and correct design decisions will be more accurate if computer aided optimization and simulation is used as a planning technique. It will usually be beneficial to involve directly in such work. Use of such techniques is essential when the final elevator system itself will be computer controlled to achieve optimum operational performance, as will be the case for most large building complexes.
The traffic flow in hotel is dependent on the type of hotel and its layout. Traffic peaks normally occur in the early morning and in the evenings, as guests leave and enter, or access the communal facilities, such as restaurants and bars. At these peak times, traffic flow can be approximately 10 percent (5 percent in each direction) of the hotel guest population requiring elevator service in a five-minute period. In the absence of other estimates, this value is used for planning.
Hotels where large scale events are held, such as conferences and banquets, may often have periods where traffic flows substantially exceed the recommended planning figure. If a hotel’s owner or developers require it, planning criteria should be amended to a higher value, to ensure the elevator system can cope with such demands. Ideally large suites should be located on lower level.
What is an acceptable service interval in hotel can vary greatly according to its type and location. In smaller, older or provincial establishments longer intervals up to 60 seconds can be acceptable. In modern, international hotels not more than 30 seconds will be acceptable.
In addition to guest elevator systems, most hotels will require provision of separate elevator systems for staff movement, catering supplies, linen and other purposes.
- Residential Buildings:
Traffic patterns in residential buildings, either private or publicly owned, usually resemble those of hotels. Peak traffic density usually occurs in the early morning, but peaks will vary both in time span and in intensity. The peak traffic value for use in planning is suggested as 6 percent of total building population.
The acceptable service interval for residential buildings is a highly variable quantity and must be assessed on criteria relevant to each application. Thus it is difficult to give general guidance. However, it should not be overlooked that extended waiting due to low quality of service can antagonize and frustrate elevator users. This in turn can lead to unpleasant reaction and social problems.
If there is a requirement for a residential elevator system to access public communal areas, service levels must be given special consideration. Elevator equipment must also be designed to suitable standards for such application. Often the principal, such as a housing association or local authority will set the planning criteria.
Generally vertical transportation requirements are laid down by the operating authorities of hospitals, consultants etc., whether public or private. Very careful research is necessary to plan each individual hospital elevator project correctly.
There will usually be a requirement to provide several elevator systems. Apart from those for specific patient and medical use in a hospital’s day-to day work, elevators will be required for patients, visitors, catering, linen transport, waste disposal and similar purposes.
- Specialized buildings:
Leisure centers, shopping malls, retail developments, air terminal and entertainment complexes are typical of the kind of specialized buildings, which require careful individual study of traffic flow and density. Often the vertical transport facilities for passengers will be a combination of elevator and escalators and there will be separate elevators for goods transport.
Panoramic elevators are often selected for use in specialized building for aesthetic reasons and to provide viewing platforms. Their use has added design implications, which do not apply to standard passenger elevator designs. Such elevators should rarely be used as the prime means of vertical transportation in a building scheme.
- Modernization of Elevators:
In refurbishment projects, the problems will usually be to upgrade within the physical constraints of an old system or add an elevator system where none existed. The design of a system should still be based on projected traffic flow, but the realities of each situation many have greater influence on design.
There will be a greater need to use more innovative arrangements, such as adoption of the latest microprocessor based VF control system for improved operational traffic handling.
Hydraulic elevator systems can be used in low raise situation. They have the advantage of minimizing disruption by requiring less construction work and with no machine above, do not pollute existing rooflines. Modularity design enables elevators to be dimensioned to match existing wells to optimize building usage. Similarly, step-by-step replacement of parts to upgrade old control system, renew outdated entrance systems and aesthetic improvements can help provide flexibility to a refurbishment program. Logistic considerations form an essential part of early planning.
Modernization packages can be tailored to suit specific client and building requirements, which provide inconvenience and disruption to activities in a living building and reduced shutdown periods.
Benefits of modernization are:
- Greater reliability due to incorporation of latest technology,
- Savings in energy costs,
- Smoother and more comfortable ride,
- Reduced waiting time, noise and vibration,
- Accurate floor leveling,
- Optimum system efficiency.
- More pleasing aesthetics, face lifted car interiors resulting in enhanced prestige to your building,
- Comfort from the latest in elevators safety technology,
- Most importantly, satisfied building occupants.
- Location of elevators:
Normally, the most efficient methods of locating elevators to serve an individual building are to group them together. A group has a lower average interval between car arrivals than a signal elevator. Groups should be located for easy access to and from a main building entrance and should normally be located centrally for generally age ease of passenger transit throughout the building.
If a building is of a design with areas which gives long distances to the central elevators groups, it may be efficient to install and additional elevator for local area inter floor traffic. For complex buildings, the principles for location of elevator can be different from those indicators.
- Grouping of elevators:
A group of elevators should be designed in a manner so that they are located closely to minimize the walking distance between entrances. Waiting passengers can then react quickly and access car swiftly without detrimental effects to the quality of overall service.
Lobby areas, especially the main once, should not be in the path of passageways. Any potential for confusion between waiting passenger and passersby should be avoided by having separate lobby areas.
There are two options for grouping two or three elevators. For four elevator, option are shown below is preferable as four elevators in line because sufficient increase in passenger walking distances to diminish operation efficiency.
The lobby width, of twice the car depth, when elevators are placed opposite each other in a group, determines the size of the elevator machine room. If the lobby width is decrease below that specified, it could provide difficulties in machine room layout.
- Elevator layout:
An elevator arrangement is a term used to describe the configuration used for hoisting and elevator car. The main criteria, which determine the lay out to be used, are
- Design of building, particularly the physical constraints imposed by dimensional are loading limitation,
- Performance of the elevator system in speed and capacity,
- Optimum utilization of available floor space.
Electric Traction Machine above:
- Roped (the rope liner speed and car travel speed are the same). An economical efficient roping system applicable to many medium and high-speed elevators systems of and a diverter sheave will be fitted.
- Roped (the rope linear speed is twice the care travel speed).
This layout permits a machine to carry twice the elevator car load.
Electric Traction Machine below:
- Single wrap. Generally restricted to 30 meters. The headroom required above the elevator well is reduced in this lay out by having machine mounted at or below the lowest floor level served. The increased length of rope can limit travel and the method doubles the load on the building structure or elevator.
Indirect side acting Hydraulic low Headroom:
The elevator care is side guided and suspended on ropes in this layout. Hydraulic elevator systems provide optimum low headroom solutions for low-rise installations. They are particularly advantageous for existing buildings or other situations where loading on the structure of the building must be kept as small as possible. In addition the machine room of a hydraulic system can be located remotely, supplying power to the lift cylinder from up to 15 meters away. Hydraulic methods are not generally adopted for intensively used elevator
- Machine Room less Elevators:
The benefits of a lift that need NO MACHINE ROOM are remarkable.
It means greater design flexibility.
FOR CONSTRUCTION COMPANIES:
Streamlined installation with lesser construction demands and interference.
Lower construction costs and more saleable space. With the machinery neatly placed at the top of the hoist way, it delivers all these advantages. Equipped with variable frequency technology, it also offers vital performance benefits: a smoother and quieter ride, floor leveling accuracy and energy savings. Driven by a machine best known for its reliability in the elevator industry is fitted with a state-of-the-art modular control system, ideal for mid-rise residential apartments. The combination ensures exceptional reliability and performance of the elevator.
- ADVANTAGES OF MRL ELEVATOR:
- Improved aesthetics of the building with the absence of the machine room.
- Additional saleable space for the builder.
- More comfortable trip.
- Cost saving (civil and electrical) by elimination of the machine room.
- Improved leveling.
- Energy saving.
- Drive System:
Modern elevator systems are driven by hydraulic or electric motion. They main criteria that decide the method to be used for a specific design are:
- Elevator speed.
- Intensity of elevator usage.
- Head room constraints.
- Passenger comfort.
- Energy consumption.
- Site constraints.
- Capital and operating costs.
Machines used to provide electricity traction drive are designed with three main type of drive. Generally these are:
- Single speed AC geared Machine up to 0.7, meters per second.
- Variable Voltage Variable frequency geared machine for speeds up to 2.5 meters per second,
- Variables voltage variable frequency gearless machine for speeds of 2.5 meters per second and above.
- Hydraulic Systems:
Hydraulic drive systems have a motor-pump unit which supplies pressurized fluid via flexible hoses to a hydraulic cylinder. The cylinder provides the elevator car with motion indirectly. An electric motor drives the pump. Control of the system id by electro-hydraulic valves; ascent is driven under pressure and descent under gravity using the weight of the elevator car.
They are ideally applicable to low raise non-intensive traffic and buildings with height restriction.
- Single Speed AC Geared Machine:
Simple single speed AC motors are used in economy elevator system where leveling accuracy of + 75 m is acceptable and where passenger comfort is not an over-riding constraint. Motors in such systems are driven directly from the AC power supply.
Stopping is via an electro-mechanical brake mounted on the drive motors. The fixed parameters of such systems make leveling accuracy dependent on elevator carload.
Variable Voltage Variable Frequency Geared Machines: AC motors are recommended for most variable speed geared drive applications. High levels of control and accuracy can be achieved for medium speed elevators. Varying the frequency and voltage of theca current supplied can control AC motors. It results in a system of great accuracy, very smooth ride and high operating efficiency.
- Variable Voltage Variable Frequency Gearless Machines:
Gearless machines are used in high-speed elevators for high-rise application. The increasing trend is to use efficient and cost effective high-speed variable frequency AC drives. In this the drive system has been ingeniously integrated with the latest microprocessor technology. From digital signals monitoring car position, car direction, speed and load, the voltage and current output is controlled to give a smooth drive, which is aligned through electronic logic to a pre-determined speed profile
The variable Voltage Variable Frequency system used on geared elevators provides the ultimate in performance at reduced operating costs.
Incoming main AC power is first rectified to DC and then inverted to provide controlled AC current to the elevator drive. Precision monitoring of motor speed and car direction, position and load enable the pulse width of the AC power supplied to the motor to be adjusted to ensure that elevator speed is maintained very accurately to an ideal profile.
Pulse width modulation control of AC motors has tremendous advantages compared with the older Servo control techniques, namely:
- Total control at stages of the motion cycle,
- A consistent fully adjustable smooth ride,
- Excellent leveling accuracy under ail conditions,
- A higher power factor,
- Lower starting currents.
- Energy saving through refused power consumption,
- Quieter, cooler running.
- V3F THE OPEREATING PRINCIPLE:
The V^F utilizes the most efficient way to regulate the speed of an AC motor, through electronically controlled motor voltage. A sophisticated converter / inverter system first rectifies the three phase AC voltage of the network to DC voltage. Pulse width Modulation (PWM) technique with high-switching frequency is then used to operate power transistors in a way that converts DC power back into variable voltage and variable frequency AC power to drive the elevator hoisting motor. Increasing or decreasing the motor voltage and frequency in accordance with a computed speed reference achieves the desired speed.
The compact V^F drive module is interfaced with the elevator control computer, which issues start, stop and operating mode commands. The drive system works intelligently in all modes and phases of elevator operation. There are different V^F models to precisely meet the requirements of elevators of different capacity/speed combinations. All of them share the same technology strengths and operating principles, ensuring the unique combination of V^F benefits.
- THE V3F RANGE:
For the low speed range up to 1.0m/s elevator speed, simplicity and economy are required in addition to energy savings, low supply currents, quit operation, precise stopping and passenger comfort. The V^F-20 system is used in this speed range. For medium and high speed elevators up to 2.00m/s, the V^F-20 system with a high degree of sophistication in electronics is used. For such elevator applications, to meet the more demanding tenant, building and elevator system requirements, the V^F-20 is built with a number of special features.
- Velocity feedback ensures that the elevator follows precisely an optimal speed pattern, producing minimal flight times and high handling capacity, as required for medium and high-speed elevators.
- Automatic reveling compensates for rope stretch noticeable at high travels and maintains the elevator car precisely at floor level.
- Adjustable acceleration and jerk rate settings allow ride performance to be optimized depending on the nature of building occupancy.
- BUILDING COST SAVINGS:
A characteristic of the V^F technology is that the drive absorbs only active current from the network. This maintains the power factor close to unit at all times. The older systems rarely reach a value better than 0.07. The high power factor and the minimal motor slip even during start and acceleration, reduces V^F line current drastically. The low starting current of the V^F system, means power supply sizing smaller by more than 50 percent compared with traditional system, this translates into direct building cost savings:
- Smaller mains power switch and cable.
- Smaller standby generator sets.
Taking the example of a standard 6 passenger 0.63m/s apartment elevator, the traditional single speed drive system would require 32 Amps mains switch\, 6 sq.mm cable and 30 KVA standby generator, whereas, the same elevator with V^F drive system only needs 16Amps mains switch, 2.5 sq.mm cable and 12.5KVA generator set.
- REDUCED ENERGY CONSUMPTION:
Since the motor starting currents are much smaller in V^F drives, the thermal losses in the motor are reduced, which translates into substantially lower energy consumption. The savings are close to 50% compared to traditional AC and DC drives. Again taking the example of the 6 passenger 0.63 m/s elevator, the traditional single speed system, in average usage, consumes around 6000 units per year. An equivalent v^f elevator requires only around 3000 units. The energy savings can be very substantial in large capacity high-speed elevators in buildings with intense traffic.
- SILENT& SMOOTH EFFICIENCY:
V^F controlled hoisting machines are extremely smooth running, eliminating noise, vibrations and jerks that could be sensed in the elevator car. The extraordinary silence, smoothness and efficiency of a V^F installation are a credit to any building. The V^F drive follows smoothly the speed reference generated electronically for each run. The acceleration, deceleration and jerk values are preset at the factory.
In the medium and high-rise versions their values can be individually set on site for an ideal balance of dynamic performance and passenger comfort.
- LONG TERM RELIABILITY:
V^F electronics reduction gears and the cool-running, reliable AC motors are designed, engineered and manufactured exclusively for elevator application. Combining V^F with well-proven control and door systems ensures technological consistency and long service life the real payback for the initial investment.
- MODERNIZING WITH THE V^F MODPAK:
The V3F range also includes the purpose designed modernization version, the V3F Modpak’ for upgrading of existing AC elevators. The drive machine with the AC motor, still in serviceable condition can be retained, which reduces both cost and downtime. The modernized elevator has all the benefits of a normal V^F controlled elevator.
- Elevator Entrances:
Because an elevator car normally spends a large percentage of its time stationary during passenger transfer, the efficiency of the entrance system is a major factor in overall elevator system efficiency. The principal elements affecting entrance efficiency are;
- Opening width
- Door configuration
- Door drive system
- Passenger protective systems
- MANUAL ENTRANCES:
Manual entrances are normally provided on low speed small capacity elevators where budget is a constraint, such as low cost housing segments. Normally manual entrance arrangements provided are imperforated collapsible door in car and Imperforated collapsible doors or swing doors on landing.
- POWER OPERATED ENTRANCES:
The most efficient door configuration is two panels, center opening. A usable clear opening becomes available, and passengers begin transfer, before the doors are fully opened.
Two speed, two-panel entrances-are used more at hospitals and similar buildings. They are more space effective, but lack the operational efficiency of center opening type doors.
- PROTECTIVE SYSTEMS:
Passengers are protected from the closing doors by two principal methods;
- Electro mechanical pressure detection
- Electronic door detector.
In the first method, sensors incorporated into the door drive mechanisms detect slight body contact pressure. Actuation will check and reverse door movement, allowing passengers to pass.
The second method is used in the highly efficient and sophisticated ‘intelligent’ systems.
The screen of infrared beams acting as a safety curtain across the door entrance detects an obstacle when the doors are closing the doors then revert to an open positions.
- ELEVATOR OPERATIONS:
There are three key elements to the operational control of an elevator system:
- Passengers requiring an elevator inform the system by a landing call.
- Passengers in an elevator care inform the system of their destination by a car call.
- The elevator’s operational control system responds to passenger’s demands by issuing appropriate commands to the elevator’s motion controller.
Most of control systems use microprocessors to handle system commands. They are of modular design, ranging from the simplest form of control to the most up to date and sophisticated.
- SINGLE AUTOMATIC PUSH BUTTON OPERATION:-
- The simplest system. The car rests at the last floor served. When a landing call is received, the car travels to the relevant floor. Once the passenger has boarded and indicated the destination (car call) the car is exclusive to that passenger, and will ignore other landing calls until the destination floor is reached.
- During this time, pressing landing call buttons will illuminate the UP/DN arrows lamps and the call button will not light.
- The control system does not memorize landing calls received while the car is in use. Landing call buttons must be re-pressed when the UP-DN lamp extinguishes. The system is recommended only for light traffic, and with manual entrances to a maximum of eight floors.
- DOWN COLLECTIVE OPERATION-ONE CAR (Single car):
- The car normally rests at the main floor. Main floor has an ‘UP’ call button. Floors above the ‘DOWN’ call buttons. The controller memorizes landing and car calls. This system is ideal for residential buildings. When more than one landing call is received, the car will stop at other landing calls during the descent.
- During an ‘UP’ journey from the main floor, the car ignores all landing calls; stopping at car calls in floor sequence. After the highest car call floor, the car will descend, stopping at landing and car calls in floor sequence back to the main floor.
- The system is suitable only for light traffic. Inter floor traffic is poorly served by this system and it should be used only when traffic is mainly up floor, and down to, the main floor e.g. residential buildings.
- DOWN COLLECTIVE OPERTION-TWO CARS (DUPLEX):
Operates as the simplex but….
With no calls in the system, one car rests at the main floor, the other normally at the last floor served, unless that was the main floor, when the car will park at a midway point. When a landing call is received, the microprocessor calculates which car is nearest to the call. If a series of landing calls is received, a car will be dispatched to the highest call, and then work down in floor sequence.
The microprocessor constantly monitors the system and re-assigns calls when necessary.
- FULL COLLECTIVE OPERATION-ONE CAR (SIMPLEX):
- ‘UP’ and ‘DOWN’ landing call buttons are provided on all floors except the lowest floor, which has an ‘UP’ button, and the highest floor which has a ‘DOWN’ button. Landing call buttons illuminate when pressed to indicate that the call is registered.
- Landing calls and car calls are memorized and handled in logical sequence according to the direction of travel of the car and independent of the order in which the calls were registered.
- The full collective system handles inter-floor traffic well and is suited to most applications within its handling capacity.
- FULL COLLECTIVE OPERATION-TWO CARS (DUPLEX) OR MORE:
- Duplex operates as the Simplex but…
With no calls in the system, one car rests at the main floor, the other normally at the last floor served (unless it was the main floor, when the car will park at a midway point).
When a landing call is received, the microprocessor calculates which car is nearest to the call, traveling in the required direction. Each car responds to its own car calls in logical sequence, depending upon direction of travel, and takes landing calls as assigned by the microprocessor. The microprocessor constantly monitors the system and re-assigns calls when necessary.
When the full collective (up to 8 elevators) Duplex principle is extended to cover more than two lifts to operate them as a coordinated system it becomes a full collective group. With no calls in the system one car rests at the main floor, the others are distributed evenly throughout the other floors. Each elevator has its own microprocessor controller and each controller has the ability to perform the group supervisory role, so that, in the event of an elevator failure, the remaining elevators continue to operate as a coordinated system.
- ELEVATOR MAINTENANCE:
The initial plans and designs for an elevator system are merely the start of a long equipment life cycle. Elevator systems will remain in operational use often long after those responsible for their initial planning and installation have left the scene for new projects. However, the long term success for new projects. System is substantially affected by the decisions for its operation and maintenance that are made during the planning and creative stages.
- Preventive maintenance – to ensure continuity of safe and efficient operation.
- System monitoring -to enable impending faults to be detected and corrected and overall system performance to be assessed.
- Corrective maintenance – to effect rapid restoration of service when a fault occurs.
- Inspection and audit -to determine that an installation is being maintained in a safe and effective manner.
- Passenger assurance -to make sure that the disturbance and distress to passengers is minimized should a fault occur.
Address all the above requirements through a company Maintenance. It is a modular range of services. The main components of maintenance are…
- Programmed maintenance
- Online telephone service
- Call out service
- Annual surveys, quality survey and special inspections.
Programmed maintenance; is the corner stone of maintenance. An efficient technique, refined by year of site experience, it ensures regular preventive maintenance to check, adjust and lubricate the key components of an elevator equipment.
Online telephone; is a service at main centers that provides a computerized point of contact to help with difficulties or if failures occur. Customers can be sure that there is alv\/ays someone to help v\/hen needed.
Surveys and inspections are necessary for several reasons. Safety surveys must be carried out to ensure compliance v\/ith statutory standards and certification. Quality surveys should enable regular review of maintenance and its effectiveness, and annual surveys should be implemented to keep a close eye on the overall conditions of a system and to ascertain if improvements and enhancements are necessary.
- ELEVATOR SAFETY:
FOR MUTUAL BENEFIT:
An elevator is a life-time investment. It is a high-tech product incorporating sophisticated electronic circuitry. And so the job of installing an elevator is a specialized one. Trained and skilled technicians facing many odds at construction sites perform it.
The customer plays an important role in enhancing technician’s efficiency. By strictly adhering to the following set of guidelines, the customer will not only provide a safe working environment for our technicians but will also protect the elevator from possible damage at site. This in turn will result in controlling cost and also saving valuable time-thus mutually benefiting both the customer and company.
- Safe access way:
The passage should be clear of any tripping hazards. The staircase to have sufficient tread area preferably of masonry construction and equipped with handrails. The machine room door to always open outwards and only inwards if the platform is less than the full swing of the door + 600mm.
Safe entry to m ach in e room is a p re -requisite to e n ab le technician s, Engineers, in specters (lift, building, fire) and later, technicians to move in and out freely. In an emergency it helps to quickly things right.
- Earth Leakage Circuit Breakers:
Provide ELCB on main 230 V-1HP input to machine-room. This will supply the hoist way light, pit lights and car light. The ELCB helps to minimize the danger of shock to elevator users and to mechanics.
- Lighting / Ventilation:
Adequate lighting to carry out mechanical electrical work safely and efficiently. Adequate ventilation to keep machine room temperature below 40°C Faultfinding and repair work can be performed quickly to minimize inconvenience to the customer. Cool machines run more efficiently with lower failure rate.
The trap door must be fabricated to comfortably support the weight of persons walking over it while carrying out their normal course of work. The trap door cover should not suddenly give way when two or three persons stand on it. A poorly designed trap door may suddenly collapse endangering the lives of technicians working in the machine room.
- Hoisting Beams/Hooks:
Must have safe working load as per Indian standard of elevators.
A Firm, stable, and sturdy scaffolding erected in the hoist way. Technicians become more confident when they step onto strong scaffolding. Their fear of falling is greatly reduced an d they can concentrate better on giving you a quality Job faster
Barriers should be provided across all open entrances in the form of 3 strips at 42”, 18” and a toe board 4” in highest. An adequate barrier will save any curious passerby or technicians from accidentally walking into and falling down an unguarded hoist way-avoid chance of fatal accident.
- Separator screen.
In case there is more than one elevator in a common lift well, a separator screen should be provided between the two-elevator hoist way. This could be either of masonry construction or a wire mesh stretched between the separator beams.
Note; in case of “Fire Lift”, the separator must be a masonry wall.
This minimizes the risk of any elevator component accidentally protruding into the adjacent hoist way where the other elevator is running.
Properly earthed lighting arrangements to be provided in the hoist way in the form of 230v, 100w bulkhead fittings at each floor level with its switch in the machine-room. The pit light should be controlled individually be a switch accessible from ground floor entrance. The line to the midway junction box that feeds the care light should also be controlled by a switch provided in the machine-room. Visibility in the hoist way is very poor especially when landing doors are of the panel type. Emergency repairs take much longer where lighting is inadequate.
A steel ladder should be provided in the pit for convenient access. The ladder must extend to at least 1’ above the lowest landing as indicated in the illustration. Pit-light switch and pit stop must be accessible from entrance.
A strong ladder is required to provide safe access to the pit to work on the elevator and to carry out routine maintenance of elevator components located in the pit.
- Water Proofing.
The elevator pit well must be thoroughly water proofed. If water enters the pit well it could render the traveling cables unsafe and also cause the other equipment to rust. Water in the electrical cables can cause serious malfunctioning of the elevator and in heavy rapier bills.
In the construction stage, access to the elevator and its adjacent working areas must be safe at all times. There should be no tripping hazards, loose hanging electrical wires or dangers from any falling objects. Accidents to technicians could prove to be fatal and lead to legal complications. Serious injuries to technicians at the erection stage could disrupt installation and job completion schedules of the elevator. Such delays are better avoided for obvious reasons.
Basic Amenities like safe drinking water and reasonable toilet facilities for technicians working at site must be provided. Adequate measures to control the means of mosquitoes must also be taken. In the absence of safe drinking water, technicians are prone to fall it. Contaminated water could lead to dangerous diseases. Presence of mosquitoes may cause malaria. If adequate toilet facilities are not provided technicians
may have no alternative but to use corners and niches rendering the site highly unhygienic.
- Elevator Operational Features: –
The number of standard operational features that would be considered luxuries on most other elevators.
If the load in the car is less than 3 persons and the controller detects too many pressed floor buttons for the number of passengers in the car, it cancels all the car calls. This feature helps avoid unwanted elevator operation caused by mischievously or mistakenly registered car calls.
- Attendant Service
An elevator attendant can perform elevator operation by using the control buttons (UP, DOWN, NON STOP) located in the service cabinet and the floor buttons on the car-operating panel.
- Automatic Fan Switch
The fan in the car is automatically switched off if there is no hall or car calls for a fixed period of time that can be specified by you.
- Car Failure Operation (Safe Landing)
In case a car stops between floors, the controller will automatically investigate the cause of failure. And if found safe to operate, the car will be controlled to travel to the nearest landing at a slow speed. Upon arrival, the doors will automatically open.
- Door Failure
When the door is prevented from being closed by a foreign substance caught in the threshold groove or in a door edge, the doors automatically try to remove the substance by repeated opening and closing.
It may happen that an object is caught between the opening door and the door receptacle, preventing the doors from opening fully. In that case, after a fixed period of time, the car will travel to the next floor and the doors will automatically open.
- Double Door
If both, up and down hall calls at a certain floor are registered, and they are the last call in the car direction, the car proceeds to the floor and opens/closes the doors. After that, the car reversed its travel and opens/closes the doors again unless no car calls are registered at that floor.
- Emergency Alarm.
At the gentle press of a button located in the car-operating panel, the emergency alarm is activated.
- Hall Call
If the elevator car arrives at a floor to answer hall call and the hall buttons is kept activated for longer than a predetermined period of time, the car will not be held up at the floor, but will close its doors and proceed to respond to another call.
When the independent key switch is turned on, all registered hall calls are cancelled and the elevator responds only to car calls. No hall calls can be registered during this service.
When the carload exceeds 80% of the rated duty load, the elevator does not answer hall calls. When the carload becomes less than 80% of the rated load, the elevator returns to normal operation.
- Motor Overheat
If an abnormal temperature in the elevator motor is detected, the car is forced to stop at the nearest floor and open the doors. It automatically reverts to normal operation as soon as the motor has cooled.
Moderate Incoming Traffic (MIT) -Applicable for 3 or more car group operation this is a group function. MIT shall be initiated whenever two fully loaded cars leave the lobby within 20 seconds. All cars shall return directly to the lobby when all their registered car calls have been answered. MIT operation shall continue for 120 seconds after the departure of the last fully loaded car.
Moderate Outgoing Traffic (MOT) -Applicable for 3 or more car group operation MOT minimizes long waiting intervals above the lobby. MOT shall commence on the arrival of two fully loaded cars at the lobby within a selected time interval.
- Multi-Car group Control
A computer provided for each of the elevators in a group, monitors and controls every aspect of elevator operation on a real time basis. This microprocessor control system flexibly reacts and makes elevator dispatching decisions for optimum coverage of every floor, keeping passenger waiting time to the bar minimum.
- Nudging Door Operation (with DC operator)
When the doors remain open for more than the fixed door open time (approximately 20 seconds), a buzzer sounds and the doors will be closed automatically. The door-sensing device is rendered inoperative, but the door open button and the safety shoe remain operative.
- Safety Shoe Gate Switch
The doors revert to open if the safety shoe detects an obstacle when the doors are closing.
- Separate door Times.
When the car responds to only a car call, the doors are controlled to open and close in a shorter time, say 20 seconds. On the other hand, when a car stops to respond to a hall call, a longer time can be set say 40 seconds. If the door open button is pressed when the doors are closing, the doors will remain open for a shorter time than normal, say
When an overload is detected the car does not start and the doors open. A buzzer is activated and the sign on the car-operating panel is lit. The elevator operation resumes only upon removal of the overload.
- Automatic Rescue Device (ARD).
This is a battery-operated device, which comes into action in case of power failure. Within a few seconds of power failure, subject to all safeties being in position, the car is moved at slow speed to the nearest landing and the doors open.
- Electronic Door Detector.
The doors revert to open if the screen of infrared beams acting as a safety curtain across the door entrance detects an obstacle when the doors are closing.
- Emergency Power
In case of a power failure, standby power equipment (provided by owner) enables the elevator to return to a predetermined floor for passenger evacuation and to subsequently continue operating depending on the standby power capacity.
- Fire Alarm Home Landing.
When a fire-detecting device installed in the building (by owner) is activated, the elevator rushes to a predetermined emergency purpose landing for passenger evacuation. After which the elevator parks at the landing with doors open and remains inoperative.
- Fireman’s Service.
Upon switching on the fireman’s switch in the hall of a predetermined floor, the elevator rushes to that floor for passenger evacuation. After which the elevator is ready to be used for firefighting.
- Hall Lantern & Car Arrival Chime.
These fixtures visually and audibly notify passengers of the arrival of an elevator in advance-two chimes in the down direction and one chime in the up direction. This facility helps visually handicapped Passengers.
The elevator automatically returns to the predetermined home landing after the last call has been answered.
A 3-way communication facility is provided, which connects the elevator car, reception area and the machine room.
When the parking switch is turned on, the elevator proceeds to the parking floor responding to calls on the way. On arriving at the park floor, the car fan is automatically turned off and the hall position indicator displays “PARK”. Only one parking floor can be assigned.
- EMERGENCIES IN ELEVATORS:
When you are stalled in the elevator due to power failure or breakdown…
- Push door open button to check if the doors open.
- Push the alarm button in the car to ring the emergency alarm.
- Press intercom button to communicate with the lobby.
Remember; you are safe inside the elevator. Do not jump out.
- Instruction for security and people outside the elevator When the intercom receiver rings, communicate immediately with the passenger trapped inside the car. Identify the floor position where the car would have halted. Go to the nearest floor where the elevator is, let the person inside the elevator feel at ease, and tell him/her the following things”
- You are absolutely safe inside the car
- The car is ventilated—you will not suffocate
- We are calling company engineers for immediate help
- Call the elevator company office to inform that someone is trapped in the elevator.
- The elevator company staff nearest to you will come for rescue and rectify faults if any.
TO AVOID PANIC AND INCONVENIENCE—it is advisable to install
Automatic Rescue Device to assist rescue during power failure.