Glossary of Terms : A - E


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.

Lift car

A part of the lift which carries the passengers and/or other loads.

Lift control system

The devices and functional principles for executing the calls and commands given by the passengers.

Lift group

An lift group consists of two or more lifts which are sharing the same landing call buttons (and running under the same group controller). See also lift bank.

Lift shaft

The space in which the lift car and the counterweight, if there is one, travels; this space is usually bounded by the bottom of the pit, the walls and the ceiling of the shaft.

Lift speed

The momentary speed of the lift car in the lift shaft. Not the same as rated speed.