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Offices: Daytona Hollywood Palm Beach Orlando Tampa & Port St. Lucie |
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What is an Elevator Consultant?
An Elevator Consultant is someone who specializes in the design, testing, and maintenance inspection of elevators, escalators, dumbwaiters, and horizontal people movers (moving walks).
Elevator Consultants work for property owners, contractors, architects, engineers, municipal code enforcement bodies, legal counsel and insurance inspectors or adjusters for the following purposes:
 | Design Elevator Systems for Architects and Engineers
including: Elevator bank traffic studies, component specifications, and
may provide drawings for incorporation into contract bid packages. |
| Perform ASME A17.1 QEI-1 certified inspections under
the auspices of the Municipal Code Enforcement Officials. |
| Provide maintenance audits to verify contract
compliance with the maintenance provisions of the contract, confirm
compliance with the ASME A17.1 maintenance provisions, and determine the
long term viability of the equipment as required by the Original Equipment
Manufacturer's (OEM) maintenance requirements. |
| Elevator Consultants may specialize and provide a variety of additional services including: Modernization/renovation consulting, damage assessment, service contract review, plans review and/or project management, expert witness testimony, litigation support, accident investigation, and ADA and Accessibility Code compliance review. |
Experience required includes: Education and/or experience in mechanical engineering, specific training in elevator construction, familiarity with model codes and standards, and testing by certified ASME licensing bodies for QEI-1 inspections.
A professional Engineering license or degree is not required for elevator consulting.
Some elevator support system designs such as Electrical Engineering for building power supplies, Structural Engineering for steel and/or masonry support, or architectural building construction will likely require specific design professional license. This "work by others" is not the responsibility of the Elevator Consultant who provides specialized knowledge and experience for vertical transportation equipment whereas another specialized Engineer or Architect may not be qualified.
It is considered unethical for an Elevator Consultant to practice the profession of Engineering/Architecture outside of their area of expertise, and for Engineers/Architects to work outside of their professional experience. Elevator Consultants, therefore, provide an important and necessary resource for proper design delegation which serves the safety of the public.
History of the Elevator
Elevators began as simple rope or chain hoists. An elevator is essentially a platform that is either pulled or pushed up by a mechanical means. A modern day elevator consists of a cab (also called a "cage" or "car") mounted on a platform within a enclosed space called a shaft or more correctly a "hoistway". In the past elevator drive mechanisms were powered by steam and water hydraulic pistons.
In a "traction" elevator, cars are pulled up by means of rolling steel ropes over a deeply grooved pulley. The weight of the car is balanced with a counterweight. The friction between the ropes and the pulley furnishes the traction which gives this type of elevator its name.
Hydraulic elevators use the principal of hydraulics to pressurize an above ground or in ground piston to raise and lower the car. Roped Hydraulics use a combination of both ropes and hydraulic power to raise and lower cars. Recent innovations include permanent earth magnet motors, machineroomless rail mounted gearless machines, and microprocessor controls.
Which technology is used in new installations depends on a variety of factors. Hydraulic elevators are cheaper, but installing cylinders greater than a certain length becomes impractical for very high lift hoistways. For buildings of much over seven stories traction elevators must be employed instead. Hydraulic elevators are usually slower than traction elevators.
Elisha Otis's Elevator Patent Drawing, 01/15/1861.
In 1853, Elisha Otis introduced the safety elevator, which prevented the fall of the cab if the cable broke. The design of the OTIS safety is virtually identical to that used today. It consists of a knurled roller that is locked below the elevator platform at the safety plank when the elevator descends at a given speed, which is monitored by a governor device.
On March 23, 1857 the first Otis elevator was installed at 488 Broadway in New York City. The first elevator shaft preceded the first elevator by four years. Construction for Peter Cooper's Cooper Union building in New York began in 1853. An elevator shaft was included in the design for Cooper Union, because Cooper was utterly confident a safe passenger elevator would soon be invented; the shaft however was circular because Cooper felt it was the most efficient design. Later Otis designed a special elevator for the school. Today the Otis Elevator Company, now a subsidiary of United Technologies Corporation, is the world's largest manufacturer of vertical transport systems, followed by Schindler, Thyssen-Krupp and Kone, in order.
The first electric elevator was built by Werner von Siemens in 1880. The safety and speed of electric elevators were significantly enhanced by Frank Sprague.
The development of elevators was led by the need for movement of large amounts of raw materials including coal and lumber from hillsides. The technology developed by these industries and the introduction of steel beam construction worked together to provide the need for the passenger and freight elevators we use today.
Today, elevators are built under strict supervision of the Building Codes. Model Codes which are the standard in most US and Canadian jurisdictions require compliance with the American Society of Mechanical Engineers' standards for the installation, maintenance, and inspection of elevators. In addition other related standards are likely required to be complied with as specified by Local Authorities Having Jurisdiction.
Elevators are generally sold in prepackaged components which are inherently non-proprietary. All of the four major manufacturers sell proprietary microprocessor controls. Each manufacturer provides similar product designs, and the overriding issue for purchase is usually price and availability. In the case of renovations, the use of non-proprietary controls has become a large part of that business because it allows the owner to offer the maintenance contract to multiple bidders rather than accept a single manufacturer for the life of the elevator which can be more than 30 years. In some large campus type properties, the use of non-proprietary equipment in new construction has replaced the standard prepackaged product. Non-proprietary systems generally have a higher up front cost, but may be offset by allowing the owner to control the long term costs over the life of the elevator.
In some locations, the shaft and parts of the cab are made of transparent material for specialized "Scenic elevators." This allows riders to see outside the cab as they travel on the elevator. Some locations take advantage of this transparent material by placing the elevators along the walls of their building. This allows riders to see the outdoor environment as the cab runs along the side of the buildings.
Today, all new elevators are computer-controlled and microprocessor based. This allows the elevator system to place cabs where they are most needed in the interest of smooth running, with behavior based on analysis of building use called "Traffic Studies." Traffic Studies are done by professional elevator consultants who use specialized tools to determine the optimum size, speed and number of elevators for a building based on its peak use periods. Computer control also permits greater control of access to various floors of a building after hours and on weekends. Methods of access control include card readers, keys, and access codes entered into the control panel of the elevator.
Elevators are usually installed in a building during construction. Renovations may consist of replacements for hoistway (floor landing) doors, car doors, interior cab finishes, controls, hoist machines, hydraulic pistons and hall fixtures. In many instances the upgrading of components may require additional code compliance, these issues should be reviewed with an elevator consultant prior to the purchasing of new materials.
Elevators are inherently safe. Their safety record, that of moving millions of passengers every day, without incident, is unsurpassed by any other vehicle system. Recently, however, hydraulic elevators built prior to a code change in 1972 have been found to be subject to possible catastrophic failure. This concern is reflected in the ASME A17.1 Maintenance of Hydraulic elevators section of the 2000 edition to require verification of system integrity in underground hydraulic elevator cylinders. Because it is impossible to verify the system completely without a pressurized casing (as described below) it is necessary to actually remove the piston to inspect it. The cost of removing the piston is such that, it makes no economical sense to re-install the old cylinder, and therefore it is logically necessary to install a new one.
In addition to the safety concerns for older hydraulic elevators, there is risk of leaking hydraulic oil into the aquifer and causing potential environmental contamination. This has led to the introduction of PVC liners (casings) around hydraulic cylinders which can be monitored for integrity. Recent innovations called machineroomless elevators may soon make the use of hydraulic elevators obsolete.
Elevators are regulated by the Consumer Product Safety Commission and are subject to the provisions of that regulation body. In 2004 the CPSC published a consumer alert about the safe use of escalators.
Uses of Elevators
Passenger Service
A passenger elevator is designed to carry people and small packages. Passenger elevators are required to conform to the American Society of Mechanical Engineer's Standard A17.1 Safety Code for Elevators and Escalators in most US and Canadian Jurisdictions (In Canada the document is the CAN/CSA B44 Safety Standard which was harmonized with the US version in the 2000 edition.) In addition, passenger elevators may be required to conform to the requirements of A17.3 for existing elevators where referenced by the Local Jurisdiction. Passenger elevators are tested using the ASME A17.2 Standard, the frequency of which is mandated by the Local Authority Having Jurisdiction (AHJ), which may be a Town, City, or State standard.
Passenger elevators must also conform to many ancillary building codes including the Local or State building code, National Fire Protection Association standards for Electrical, Fire Sprinklers and Fire Alarms, Plumbing codes, and HVAC codes. In addition, passenger elevators are required to conform to the American's with Disabilities Act and other State and Federal civil rights legislation regarding accessibility.
Passenger elevator capacity is related to the available floor space. Generally, passenger elevators are available in typical capacities from 1,500 to 5,000 lb (680 to 2,300 kg) in 500 lb (230 kg) increments. Generally passenger elevators in buildings 4 stories or less are hydraulic, however, concerns with hydraulic elevators in recent years have limited their installations. In buildings up to 10 stories electric elevators are likely to have speeds up to 300 ft/min (1.5 m/s), and above 10 stories speeds begin at 500 ft/min (2.5 m/s) up to about 1200 ft/min (6 m/s).
Passenger elevators may be specialized for the service they perform, including: Hospital emergency (Code blue), front and rear entrances, double decker (2 cars on top of one another), and other uses. Cars may be ornate in their interior appearance, may have audio visual advertising, and may be provided with specialized recorded voice instructions. The concern for entrapping passengers requires all elevators to have communication connection to an outside 24 hour emergency service, automatic recall capability in a fire emergency, and special access for fire department use in a fire. Elevators are not an acceptable means of escape during a fire and should not be used by the public. Signs are required in most all US Jurisdictions to "USE STAIRS IN CASE OF FIRE."
Residential elevators, are required to conform to ASME A17.1 and may be small enough for one person while some are large enough for more than a dozen.
Wheelchair, or Platform lifts, a specialized type of elevator designed to move a wheelchair 6 ft (2 m) or less, often can accommodate just one person in a wheelchair at a time with a maximum load of 750 lb (340 kg). Platform and Wheelchair lifts are required to comply with ASME A18.1 in most US Jurisdictions.
Freight Elevators
A freight elevator is a elevator designed to carry goods, rather than passengers. (Passengers often accompany the freight, however.) Freight elevators are exempt from some of the ASME A17.1 code requirements, as defined by the words "not for public use". Freight elevators or Service elevators, may be exempt from some of the requirements for fire service, however, new installations would like be required to comply. Freight elevators are required to post a written notice in the car that the use by passengers is prohibited.
Freight elevators are typically larger and capable of carrying heavier loads than a passenger elevator, generally from 5,000 to 10,000 lb (2,300 to 4,500 kg). Freight Elevators may have manually operated doors, and often have rugged interior finishes to prevent damage while loading and unloading. Although hydraulic freight elevators exist, electric elevators are more energy efficient for the work of freight lifting.
A small freight elevator is often called a dumb waiter (see next section), often used for moving of small items such as dishes in a 2-story kitchen or books in a multi-story rack assembly. Passengers are never permitted on dumbwaiters. Dumbwaiters and other material lifts are required to conform to the related sections of the ASME A17.1 code in most U.S. and Canadian Jurisdictions.
A specialized type of freight elevator is an Automobile Lift, used to move automobiles around a parking garage or other facility. These are material lifts by definition and are exempt from the ASME A17.1 requirements, but may have to comply with the requirements of ALIALCTV if provided for in the local jurisdiction.
Stage and Orchestra lifts are specialized lifts for use in the performing arts, and are exempt from the ASME A17.1 requirements. Local Jurisdictions may govern their use, installation and testing, however, they are often left out of local code enforcement provisions due to their infrequent installation.
Dumb Waiter
A small box elevator designed for the carriage of lightweight freight is called a dumb waiter (or dumbwaiter). Dumbwaiters are required to comply with ASME A17.1 in most US and Canadian Jurisdictions.
Dumbwaiters are generally driven by a small electric motor with a counterweight and are limited to about 750 lb (340 kg). They may also be hand operated using a roped pulley. Dumbwaiters are used extensively in the restaurant business (hence the name) and may also be used as book lifts in libraries, or to transport mail or similar items in an office tower.
Types of Elevator Hoist Mechanisms
In general, there are three means of moving an elevator:
Traction Elevators
| Geared and Gearless Traction Elevators |
Geared Traction machines are driven by AC or DC electric motors. Geared machines use worm gears to mechanically control movement of elevator cars by "rolling" steel hoist ropes over a drive sheave which is attached to a gearbox driven by a high speed motor. These machines are generally the best option for basement or overhead traction use for speeds up to 350 ft/min.
Gearless Traction machines are high speed electric motors powered by AC or DC current. In this case the drive sheave is directly attached to the end of motor.
In each case, cables are attached to a hitch plate on top of the cab or may be "under-slung" below a cab, and then looped over the drive sheave to a counterweight attached to the opposite end of the cables which reduces the amount of power needed to move the cab. The counterweight is located in the hoistway and rides a separate rail system; as the car goes up, the counterweight goes down, and vice versa. This action is powered by the traction machine which is directed by the controller, typically a relay logic or computerized device that directs starting, acceleration, deceleration and stopping of the elevator cab. The weight of the counterweight is typically equal to the weight of the elevator cab plus forty to fifty percent of the capacity of the elevator. The grooves in the drive sheave are specially designed to prevent the cables from slipping. "Traction" is provided to the ropes by the grip of the grooves in the sheave. As the ropes age and the traction grooves wear, some traction is lost and the ropes must be replaced and the sheave repaired or replaced.
Some elevators have a system called compensation. This is a separate set of cables or a chain attached to the bottom of the counterweight and the bottom of the elevator cab. This makes it easier to control the elevator because the weight will fluctuate less over the entire system. If the elevator cab is at the top of the hoistway, there is a short length of hoist cable above the car and a long length of compensating cable below the car, and vice versa for the counterweight. If the compensation is cables, there is an additional sheave in the pit below the elevator to guide the cables. If the compensation is a chain, the chain is guided by a bar mounted between the counterweight rails.
Hydraulic Type
| Conventional Hydraulic elevators are quite common for low and medium rise buildings (2-5 stories). They use a hydraulically powered plunger to push the elevator upwards. On some, the hydraulic piston (plunger) consists of telescoping concentric tubes, allowing a shallow tube to contain the mechanism below the lowest floor. On others, the piston requires a deeper hole below the bottom landing, usually with a PVC casing for protection. |
| Roped Hydraulic |
| Twin post Hydraulic |
| Holeless Hydraulic elevators do not require holes to be dug for the hydraulic cylinder |
Paternoster
A special type of elevator is the paternoster, a constantly moving chain of boxes. A similar concept moves only a small platform, which the rider mounts while using a handhold and was once seen in multi-story industrial plants.
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"Elevator" and
"Elevator Consultant".