Glossary of Terms

 

The Lift Industry uses a bewildering number of specialist words when describing the various aspects of lifts and lift shafts.

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1:1 Roping

An arrangement of suspension ropes in which the car speed and rope speed are equal.

2:1 Roping

An arrangement of suspension ropes in which the car speed is one half the rope speed.

3-phase power supply

Electrical power supply that provides 3-phase alternating voltage.

AC

Alternating Current (a type of power for a lift machine).

Acceleration

A period which the lift moves at an ever increasing rate of speed, usually referring to that period from standstill to full speed.

Access control

A device or system that controls access to a lift or building.

AC System

A control system for an AC motor which has a single synchronous speed or two different synchronous speeds.

Advance door opening

A system that allows car doors to start opening before the car is fully stopped on the landing. Doors start opening when the lift car is in the door zone and the speed has decreased below the limit allowed by the regulations.

Airborne noise

Noise transmitted through the air. In lifts usually generated by the machine, ropes, control panel, doors, guide shoes and other vibrating components.

Alarm bell

A bell used to call attention and assistance. Operated by a pushbutton inside the lift car. May be located in the lift shaft, on a suitable landing, or on the lift car.

Alarm button

A button for activating the alarm bell. Also activates voice connection if remote monitoring is used. Located in the lift car, with additional buttons on the lift car roof and underneath the car.

Alarm delay time

The time the alarm button must be pressed until the signal is registered.

Alarm signal

A signal generated by pushing the alarm button.

Announcement floor

A floor where the lift announcer operates.

Anti drum element

A dampening element for reducing noise. Used for instance in lift car enclosures, door panels or control cabinets.

Ascending car overspeed protection

A safety system for stopping the uncontrolled movement of the ascending lift car.

Asynchronous motor

An electric motor where the rotating speed is not exactly fixed to the frequency of the supplied current. The difference between the frequency and rotor speed is called slip. The slip generates the motor torque.

Automatic car door

Automatically opening and closing the lift car door.

Available car area

Area of the car measured at a height of 1 m above floor level, disregarding handrails, which is available for passengers or goods during operation of the lift. Any available area in the entrance, when the doors are closed, shall also be taken into account.

Babbitt

A soft metal used to fill scratching of a plunger surface. It is also used to secure hoist ropes to there fittings.

Balanced load

A situation when there is a weight of 45-50 % of the rated load (depending on the dimensioning principle) in the lift car and the counterweight and car weights are equal.

Balancing ratio

The share (in per cent) of the Lift's rated load with which the lift car and the counterweight are in balance.

Balancing weight

Mass in counterweight which saves energy by balancing all or part of the mass of the car, car sling and the rated load.

Balustrade

A safety barrier on the lift car roof that prevents from falling to the lift shaft.

Battery drive

Optional device which allows to drive the lift car with balanced load to the nearest floor.

Bed plate

A steel or cast-iron platform on which a machine is placed.

Bi-stable switch

A device that is capable of assuming either one or two stable states. It remains in one of the states until a trigger is applied. It then flips to the other stable state and remains there until another trigger is applied.

Blocking device

A mechanical safety device to block the lift car during installation and maintenance.

Bottom clearance

The clear vertical distance from the pit floor to the lowest structural or mechanical part, equipment or device installed beneath the lift car platform, except guide shoes or rollers, safety gear assemblies and platform aprons or guards, when the lift car rests on its fully compressed buffers. See also safety space.

Bottom floor

The lowest floor in a building.

Bottom landing

The lowest landing in a building that lift serves.

Brackets (Guide Rail)

The device used to attach the rails firmly to the hoistway.

Brake

An electro-mechanical device used to prevent the lift from moving when the lift car is at rest and no power is applied to the hoist machine. On some types of control it also brings the lift car to a stop when power is removed from the hoist machine.

Brake Drum

A round, machined surface on the motor shaft, which the brake clamps.

Brake shoe

Moving member(s) of a brake, lined with friction material which, when in contact with the brake drum, holds the lift at floor level. On some types of control, it will stop the lift when power is removed from the hoist motor.

Braking force

The vertical force which stops the lift car as a result of safety gear operation. See also gripping force.

Brush

A device, usually of carbon or graphite composition, used to connect a circuit with the rotating or moving portion of a DC motor, generator or other electrical device. It carries current to and from the non-moving parts of connections.

Buffer

A device designed to stop a descending car or counterweight beyond its normal limit of travel by storing or by absorbing and dissipating the kinetic energy of the car or counterweight.

Buffer plate

A plate under the lift car sling where the buffer hits.

Building settlement

Lowering of the building as a result of sinking to the ground or shrinkage of the concrete.

Building Management System (BMS)

Personnel and equipment for supervising technical systems in a building (climatisation, heating, lifts, access control etc.)

Building tolerances

Defines the tolerances for the nominal dimensions of the lift shaft, pit, machine room, openings etc.

Built-in features

Features that are included in the basic product.

Bypass load function

A feature that makes the lift car to bypass the registered landing calls when the lift car is recognised to be loaded over a certain limit. Usually the limit is 60...80 % of the rated load.

Cab

The decorative room in which people ride in a passenger Lift.

Call centre

A place where alarms and emergency calls are received. People and computers handle the information.

Call Cancellation

The circuitry that clears a registered call using selector switching, hoistway switches, or moveable brushes or contacts.

CAN network

Controller Area Network. Bus systems which interconnect intelligent automation equipment in a peer-to-peer network.

Capacity

Indicates the amount of weight a given lift is able to support safely.

Car area

The car floor area inclusive door sill area depending on rated load / number of passengers as specified by the regulations.

Car buffer

A device designed to stop a descending car beyond its normal limit of travel by storing or by absorbing and dissipating the kinetic energy of the car.

Car door lock

A device having two related and interdependent functions: (1) to prevent (electrically) the operation of the hoist machine unless the lift car door is locked in the closed position, (2) to prevent (mechanically) the opening of a lift car door from the car side unless the lift car is in the door zone and is either stopped or being stopped.

Car emergency lighting

A battery powered light in the lift car to serve as emergency light during power failure.

Car guide rail

Guide rails used to direct the travel of an lift car in an lift shaft.

Car interior

All visible elements inside the lift car.

Car light

The car interior lighting.

Car light supervision

A function which prevents the use of an lift when the car light voltage supply fails.

Car load

The actual load inside the lift car (passengers and goods). See also rated load.

Car operating panel

The user interface for passengers inside the lift car. Includes car call buttons, alarm button, door open button etc.

Car overload indication

A set of devices to detect and inform passengers of an overload in the lift car. Triggers the lift car overload indicator.

Car safety gear

A mechanical device usually attached to the lift car sling, and designed to stop the liftcar in the event the lift car exceeds the allowed speed.

Car shell

The car structure excluding the separate (non-integrated) interior elements.

Car shell depth

The internal front-to-back dimension of the lift car shell without decorative elements.

Car shell height

The height measured from the unfinished floor to the lowest edge of the roof.

Car shell width

The internal side-to-side dimension of the lift car shell without decorative elements.

Car sill

The lower horizontal member of an lift car entrance.

Car sling

The supporting frame of the lift car, to which the guide shoes, safety gear and hoisting ropes or hydraulic cylinder is attached.

Car Top Control

A control panel on top of an lift car which, when activated, removes the lift car from normal service and allows the lift car to run at inspection speed from the car top station only.

Center Opening Doors

A door type, which consists of two horizontal sliding panels, which move in opposite directions.

Clutch

A device used in lift power door operation to engage the lift car door to the landing door by a grasping and holding movement.

Compensating Chain

A welded-link chain used for hoist rope weight compensation.
One end of the chain is attached to the underside of the lift car, and the other end is fastened to the counterweight or stationary fastening in the hoistway.

Controller

A device, or group of devices, which serves to control, in a predetermined manner, the apparatus to which it is connected. A lift controller consists of drive and control functions.

Control Valve

The device, which, on hydraulic lifts, controls the oil flow to and from the jack.

Counterweight

A component which ensures traction between the traction sheave and the suspension ropes and which comprises a set of weights to balance the weight of the car and a proportion of the load in the car often taken as 50 % of the rated load.

Counterweight area

The travelling area of the counterweight in the lift pit, isolated by a counterweight screen.

Crosshead

The upper member of the lift car frame.

Cylinder

The outermost lining of a hydraulic jack

DC

Direct Current (a source of power for a lift machine).

Deceleration

A period during which the lift moves at an ever decreasing rate of speed, usually referring to that period from full speed to leveling speed.

Deflector Sheave

A pulley, aligned with the drive sheave, which provides a path for the cables to drop straight to the counterweight.

Dispatch Control System

A system that controls two or more lifts by governing assignments in response to hall calls. Also controls zoning, peak traffic demands and parking.

Door Shoes

Devices at the bottom of horizontal sliding door panels, which stick into sill grooves and eliminate door panels swinging in or out.

Door Hanger

A rolling assembly fastened to the top of a door panel which supports and allows horizontal sliding movement of the door panel. The door track on which the hanger rolls is part of the door hanger assembly.

Door Lock

Any type of mechanical lock designed to prevent the opening of a hoistway door from the landing side.

Door Open Time

Length of time doors stand open after reaching full open position, until doors start to close provided no signal is received to shorten door time.

Door Operator

A motor-driven device mounted on the car which opens and closes the car doors.

Door Panel

A portion of the door or gate, which covers the opening and moves to uncover the opening.

Door Protective Device

Any type of device used with automatic power operated doors that detects obstructions to the normal closing of the lift doors and either causes the doors to reopen or go into some other mode of operation, such as nudging. A safe edge, a safety astragal, a photoelectric device (safe ray), and electrostatic field device are examples of door protective devices.

Door Sill

The threshold of a door opening with grooves to guide the bottom of the lift car door.

Door Track

A rail which accepts the rolling assembly of the door hanger and allows the horizontal movement required to open and close the doors. The door track is a part of the door hanger assembly.

Drive Machine

The power unit which applies the energy necessary to raise and lower a Lift, material lift, or dumb waiter car or to drive an escalator, an inclined lift or a moving walk.

Drive mode

A predefined way of operation in which the lift runs in a certain situation. Modes include for example normal drive, inspection drive and setup drive.

Drive Sheave

In rope lifts, the technical solution to provide energy to the hoisting motor and regulate its speed. In hydraulic lifts it controls the pump and the valves.

Dual entrance car

A lift car with two entrances.

Electric Eye

A light beam (or beams), which spans a door opening and, when interrupted, causes the door to reopen.

Emergency alarm

An emergency system installed on all lift cars, which comprises of a bell, a pushbutton in the car and an uninterruptible source of power, usually a battery.

Emergency Stop Switch

A hand-operated switch which, when set to the off position, stops the lift and prohibits its running.

Encoder

A device used to convert an analogue signal into digital information.

Faceplate

The decorative cover which houses control devices such as position indicators, pushbuttons, key switches, etc.

Feedback

The transmission of current or voltage from the output of a circuit or device back to the input, where it interacts with the input signal to modify the operation of the circuit or device.

Fire fighting Lift

An option where one nominated lift is allowed to be removed from normal group service for firemen's use.

Fishplate

A steel plate, which spans the joint where two lengths of guide rails meet.

Floor Selector

A mechanical, electrical, or microprocessor driven device which initiates and/or controls some or all of these functions: establish direction of travel, acceleration, deceleration, levelling, stopping, call cancellation, door operation, position indicators, and hall lanterns for an individual Lift.

Full Speed

The contract speed at which the lift should run.

Gear

A toothed wheel designed to mesh or engage with another wheel or part for transmitting or changing motion.

Geared Traction Machine

A traction machine in which the power from the motor is transmitted to the drive sheave through reduction gears.

Gearless Traction Machine

A type of lift hoisting machine on which the hoist ropes pass over a traction drive sheave, which is an integral part of the armature. Called gearless because no geared reduction unit is utilized.

Generator

An electromechanical device that converts mechanical energy to electrical energy (usually direct current).

Governor

A mechanical speed control mechanism. For Lift, it is a wire rope driven centrifugal device used to stop and hold the movement of its driving rope. This initiates the activation of the lift car safety device. It opens a switch, which cuts off power to the drive motor and brake if the lift car travels at a pressed overspeed in the down direction. Some types of governors will also open the governor switch and cut off power to the drive motor and brake if the lift car overspeeds in the up direction.

Governor Rope

A wire rope attached to a lift car frame that drives the governor and, when stopped by the governor, initiates setting of the car safety.

Goods Lift

A lift equipped to carry goods, forklift trucks etc.

Goods passenger Lift

A lift mainly intended for the transport of goods, which are generally accompanied by persons.

Groove

"Vee" - A groove in the drive sheave which produces a pinching or wedging effect on the cable, used on gearless machines. "U" - A groove in the drive sheave, which relies on friction between groove and cable, used on gearless machines.

Group Control System

A system that controls two or more lifts by governing assignments in response to hall calls. Also controls zoning, peak traffic demands and parking.

Guide rail

Steel sections with smooth guiding surfaces. The section profile is usually T shaped (machined, cold drawn or roll moulded). Guide rails are installed in a lift shaft to guide and direct the travel of an lift car and its counterweight.

Guide Shoes

(1) Devices used mainly to guide the car and counterweight along the path of the guide rails. They also assure that the lateral motion of the car and counterweight is kept at a minimum as they travel along the guide rails. (2) Guiding projections mounted on the bottom edge of horizontally sliding doors or gates, or on the sides of vertically sliding doors or gates to guide them.

Hall Call

A call registered at a landing button or fixture.

Hall Lantern

A corridor mounted signal light indicating that an elevator car is approaching that landing and the direction in which the car is to travel.

Hall Station

Device located in hall usually near the elevator to be used when calling the elevator to that floor.

Hanger Rollers

Rollers (two per panel) from which horizontal door panels are suspended.

Handrail

A hand hold support in a lift car.

Headroom

Part of the lift shaft between the topmost finished floor level and the ceiling of the shaft.

Hitch Plate

A metal plate clamped to the underside of the crosshead and to which the shackles are attached.

Hoist Rope

The wire ropes used to raise and lower an lift car.

Hoistway

The space enclosed by fireproof walls and lift doors for the travel of one or more lifts, dumbwaiters or material lifts. It includes the pit and terminates at the underside of the overhead machinery space floor, or at the underside of the roof where the hoistway does not penetrate the roof.

Hoistway Enclosure

The fixed structure, consisting of vertical walls or partitions, which isolates the hoistway from all other areas or from an adjacent hoistway, and in which the hoistway doors and door assemblies are installed.

Hydraulic Lift

Hydraulic lift where the energy is applied, by means of a liquid under pressure, in a cylinder equipped with a plunger or piston.

Hydraulic Valve

In the construction of hydraulic lifts, a valve used to regulate the flow of the fluid used to raise and lower the lift, usually a low viscosity oil.

Induction Motor

An AC motor having two parts: a rotor and a stator. The stator creates a rotating magnetic field, that induces a voltage into the rotor causing it to rotate.

Interlock

A device having two related and interdependent functions which are:

(1) to prevent the operation of the driving machine by the normal operating device unless the hoistway door is locked in the closed position. An electro-mechanical device that prevents operation of an lift unless the hoistway doors are in the closed and locked position;

(2) to prevent opening of a hoistway door from the landing side unless the lift is in the landing zone and is either stopped or being stopped.

Intermediate Landing

Any landing served by a lift between its upper and lower terminal landings.

Jack

The device which pushes the hydraulic lift.

Landing

The floor area in front of the lift entrance.

Landing door

A door in the opening of a lift shaft. Provides safe access to the lift car.

Landing entrance

An assembly that includes the landing doors and any architectural finishes associated with the entrance to the lift shaft.

Landing Zone

A zone extending from a point 300mm below a lift landing, to a point 300mm above the lift landing.

Layout

A scaled mechanical drawing showing dimensioned plan views and elevations of a lift hoistway and machine room to indicate space conditions, pertinent dimensions, sizes and location of components of the installation.

Levelling

The movement of a lift toward the landing sill when it is within the levelling zone. When the word levelling is used, the inference is that the process of attaining a level stop or position (the platform level with the landing sill) is performed completely automatically.

Levelling Zone

The limited distance above or below a lift landing within which the levelling device is permitted to cause movement of the lift car toward the landing.

Lubricator

A device, which feeds oil to the guide rail and provides lubrication for sliding shoes.

Machine room

A room where the lift machine and some electrification and control system components are located. Usually located above the lift shaft.

Main contactor

A contactor which switches the power to the hoisting motor if 1) there is a need to run the lift car and 2) the electric safety chain is complete (closed).

Main entrance floor

The floor providing the main access to a building.

Main power supply

The devices that provide power to the lift. Also known as mains.

Motor Control

That portion of a control system that governs the acceleration, speed, retardation, and stopping of the moving lift.

Nudging

A system used with automatic door operation which will give a warning signal and close the doors at a reduced speed and torque. Nudging is activated if the door remains open longer than a predetermined time.

Oil Buffer

One type of buffer which uses a combination of oil and spring to cushion the lift. It is located in the lift pit.

Oil Line

The pipe that channels the oil from the power unit to the jack.

Out of service switch

A key operated switch which is used to take the lift out of normal use.

Over Travel

A device which, when the lift attains a predeterminated speed, causes the lift to stop, and if necessary causes the safety gear to be applied.

Overspeed governor

A device which, when the lift attains a predeterminated speed, causes the lift to stop, and if necessary causes the safety gear to be applied.

Overspeed Governor Switch

It is actuated by centrifugal force and trips a switch when the lift speed has increased 15 per cent over its rated nameplate speed.

Packing Gland

(1) The substance, usually of elastic or flexible material formed in rings used in the stuffing box of the worm shaft of a geared machine or of a hydraulic lift to prevent excessive leakage.

(2) Strips or blocks of material used for shimming.

Parking

A feature for a single lift or a lift group. With this feature, the lift receives a signal to always return to a pre-selected landing after all the car or landing calls have been completed.

Passenger lift

A lift primarily used to carry passengers.

Peak

In a waveform or other changing parameter, a peak is an instantaneous or local maximum or minimum.

Pickup Rollers

Devices on the hoistway door which mate with the clutch on the car door to allow the hoistway doors to be pulled open and closed.

Pit

A portion of the lift shaft extending from the sill level of the lowest landing to the lift shaft floor.

Pit Channels

Steel channels on the pit floor to anchor the guide rails and other pit-mounted devices.

Platform

The entire floor assembly of a lift, on which passengers stand or the load is carried.

Plumbing

A method for: a) checking the lift shaft to ensure that it is constructed according to the requirements and b) determining the correct position of the components.

Position Indicator

A device that indicates the position of the lift car in the hoistway, it is called a hall position indicator when placed at a landing, or car position indicator when placed in the lift car.

Power factor

Power factor defines the ratio between true power and apparent power. The power factor of a circuit is calculated based on a formula: pf = P / S, (kW / kVA).

Power Unit

The device on a hydraulic lift which supplies the motive force to run the lift car.

Preventative Maintenance

Inspections, tests, adjustments, cleaning and similar activities carried out on lift and escalator equipment with the intention of preventing malfunctions from occurring during operation. It is designed to keep equipment in proper operating order and is done on a scheduled basis. It is also referred to as scheduled maintenance.

Pump

The device which draws oil from the tank and pushes it through the oil line to the jack to move the lift up.

Push Button Station

A decorative device containing one or more hand-operated devices (buttons or switches) by which the passenger tells the controller what action is desired.

Rated load

The load for which the equipment has been built. See also car load.

Rail Clips

Devices bolted to guide rail brackets to clamp rails firmly in place.

Relay

An electric device that is designed to interpret input conditions in a prescribed manner and after specified conditions are met, to respond and cause contact operation or create change in associated electric control circuits.

Remote alarm

An emergency alarm system working over a distance.

Retardation

The operation of reducing the lift drive motor speed from normal operating speed to stop. Also referred to as Deceleration.

Revolutions Per Minute (RPM)

The number of completed turns per minute that an object revolves around its axis.

Ride comfort

Ride comfort of a lift is defined in terms of noise level, vertical vibration, lateral quaking, acceleration / deceleration rate, and jerk.

Riser

A series of hall stations for a lift or group of lifts

Roller Guides

Guide shoes which use rollers that rotate on guide rails rather than sliding on the rails.

Rotor

The rotating element of an AC induction motor.

Safety Edge

A mechanical door protective and automatic door reopening device, used with automatic power door operators. It is arranged so that in the event the door either approaches or meets an obstruction when closing, the safe edge will actuate an edge safety switch that will automatically cause the doors to stop and reopen. It is vertically mounted to extend from the bottom to the top of a horizontally sliding panel and projects forward of the leading edge of the panel.

Safe lightray

A photoelectric door protective and automatic door reopening device for automatic power door operators. It consists of a photoelectric receiving unit and light source device arranged to project a light ray across the lift door entrance. The interruption of the light ray will cause the doors to remain open as long as the ray is interrupted, or cause the reversal and reopening of doors that are closing.

Safety gear

A mechanical safety device attached to the car frame, and in some circumstances to the counterweight frame also. The device acts to stop and hold an overspeeding car or counterweight through the use of clamping jaws closing around the guide rails. The device is activated by the speed governor.

Seal

A device mounted on the guide to minimize oil escaping around the plunger.

Secondary Sheave

A pulley on a gearless machine which serves two purposes: (1) To allow each cable to second pass over the drive sheave and (2) To deflect the cable for a straight drop to the counterweight.

Selector

An electrical device, driven by the lift, which simulates lift movements.

Shaft fascia panel

A steel plate fixed on the shaft wall below the landing door sill and above the landing door to reduce the distance between the car door sill and shaft wall.

Shim

A piece of metal or other material used to fill out a space.

Sill

The bottom horizontal member of an entrance which provides the foundation and footing for the entrance frame. The sill extends the full width of the door travel.

Single Speed Door

A type of door consisting of one horizontal sliding panel.

Sling

The basic structural frame, which consists of two sides, a crosshead and a bottom support, which supports the platform and cab of a lift.

Skirting

Decorative and protective element at the bottom of the car wall.

Specifications

A detailed itemized description of the plans, materials, dimensions and all other requirements proposed for the installation of the equipment.

Spring Buffer

One type of buffer, for lifts with speeds less then 1 meter per second, which cushions the lift. It is located in the lift pit.

Stator

The non-rotating part of the magnetic structure in an induction motor.

Suspended load

The load that includes the weights of raw car, car interior, car door(s), rated load and car sling with all accessories. The weight does not include suspension ropes, compensation ropes or chains, rope compensation device, travelling cable or counterweight.

Suspension rope

The ropes suspending the lift car and counterweight.

Synchronisation drive

A lift drive mode in which the lift drives downwards until it reaches a deceleration or synchronisation switch.

Tachometer

A device which measures the feedback of a revolving shaft.

Tank (Reservoir)

A container to store the oil used to move the lift.

Terminal floor

The top or bottom landing served by an lift car.

Through-type car

A lift with entrances on two opposite sides of the lift shaft.

Thrust Bearing

A bearing designed to withstand an axial load placed on a shaft such as that imposed by a worm and worm gear.

Top-of-car Inspection

Controls on the top of the car used by a lift engineer to operate the car at inspection speed. It provides a means of operating a lift from on top of the car at slow speed during adjustment, inspection, maintenance and repair.

Torque

A force that produces or tends to produce rotation or torsion.

The pressure, measured in foot pounds, exerted by a rotating shaft.

The turning power of a motor.

The turning effort a brake is designed to stop.

Traction

One of two methods by which the lift is moved, whereby the lift is "pulled" up by cables.

Traction Machine

An electric machine in which the friction between the hoist ropes and the machine sheave is used to move the lift car.

Traction test

A safety test to ensure that there is correct amount of friction between the suspension ropes and the traction sheave.

Traveling Cable

A cable made up of electric conductors, which provides electrical connection between a lift or dumbwaiter car, or material lift, and a fixed outlet in the hoistway or machine room.

Triplex

Three elevators in a group.

Two Speed AC

A type of traction machine powered by an AC-driven motor (actually 2 motors built into one), which has 2 distinct speeds.

Two Speed Door

A type of door consisting of two horizontal sliding panels, which move, in the same direction.

Variable Voltage

A method of controlling a lift machine, which produces many different speeds.

Worm

A shaft on which a spiral groove is cut.

Worm Gear

The gear wheel which engages the revolving worm. The rotating motion of the worm is transmitted through the worm gear to the drive sheave.

Zoning

The procedure which involves parking designated lifts to serve a specified floor or group of floors.