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Elevator & Escalator Glossary

Plain-English definitions for the terms you'll actually hear on the job or in a building manager's meeting. No code-book language.

Read this first. These are working definitions for everyday use on the job, not legal text. For the exact, binding wording of any term, check the code edition your jurisdiction has adopted (see Find your code). Where a term is defined in the code itself, the definition is in Section 1.3 of ASME A17.1 / CSA B44; the inspection terms follow A17.2, and the existing-equipment terms A17.3. Those books are sold, not published free, so this page links the catalogue entries rather than the text. Last verified: 26 September 2026.

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16 CFR Part 1201
Title 16 of the U.S. Code of Federal Regulations, Part 1201: the Consumer Product Safety Commission's federal Safety Standard for Architectural Glazing Materials. Federal-law version of the safety-glazing rules; an alternative to ANSI Z97.1 for U.S. glass/plastic balustrades.

A

A17.1 (ASME A17.1)
The U.S. national safety code for elevators, escalators, and moving walks, published by ASME. Updated on a multi-year cycle. Companion to CSA B44 in Canada.
A17.2 (ASME A17.2)
ASME-published guide for elevator and escalator inspectors. Widely used as a reference but isn't legally binding on its own. The regulatory authority adopts the inspection rules.
A17.3 (ASME A17.3)
ASME standard that imposes retroactive safety requirements on already-installed equipment. Whether it applies to a given unit depends on whether the local regulatory authority has adopted it.
A17.5 (ASME A17.5)
Standard for listing and certification of electrical equipment used in elevators, escalators, and moving walks. Tells the manufacturer what testing and labeling is required.
AEDARSA (Alberta Elevating Devices and Amusement Rides Safety Association)
Alberta's delegated regulatory body for elevating devices, set up in 1996 under Alberta's Government Organization Act and working with Alberta Municipal Affairs. The Safety Codes Council (SCC) certifies it to do in-service inspections. Do not confuse it with ABSA, the Alberta Boilers Safety Association, which is the delegated authority for pressure equipment, not elevators.
Acceptance inspection
The one-time inspection performed when a unit is first installed or after an alteration, verifying the unit meets the code as built or as altered. Requirements are in Part 8.10.
Acceptance test
The full test done before a new or altered unit is put into service. It's the baseline every later test is measured against.
ADA
Americans with Disabilities Act. Drives requirements like control-button height, audible floor/direction signals, and door-timing that affect accessibility compliance for building owners.
AHJ (Authority Having Jurisdiction)
The organization, office, or person responsible for enforcing the code. B44 also defines 'regulatory authority' as a separate term; where a law or regulation makes the code mandatory, the AHJ is the regulatory authority.
AISC (American Institute of Steel Construction)
U.S. industry body whose ANSI/AISC 360-05 standard governs structural steel design. Cited from 6.1.3.10.1 for escalator truss design.
Alteration
Any change to a unit that goes beyond ordinary maintenance, repair, or like-for-like replacement (the 'form, fit, and function' test). Triggers Part 8.7, which pulls the changed portion up to current-code conformance.
ANSI Z97.1
ANSI's safety-glazing performance standard: impact resistance, breakage pattern, and durability testing for glass intended for places people might fall against. U.S. baseline for safety-rated glass; one of the options for glass/plastic balustrades per 6.1.3.3.3.
ANSI (American National Standards Institute)
The U.S. coordinator of voluntary consensus standards. Many escalator-related standards are co-branded ANSI (e.g., ANSI/AISC, ANSI/UL, ANSI Z97.1).
ANSI/AISC 360-05
American Institute of Steel Construction's structural steel design specification, co-branded with ANSI. The U.S. design code for the escalator truss and supporting structure per 6.1.3.10.1.
ANSI/AWS D1.1
American Welding Society's Structural Welding Code (Steel), co-branded with ANSI. One of the welding standards named in Section 8.8, which covers all escalator welding through 6.1.3.13. Where the National Building Code of Canada is enforced, CSA W59 applies instead (8.8.2).
ANSI/AWS D1.3
American Welding Society's Structural Welding Code (Sheet Steel). Used when welding thinner-gauge sheet steel components. Companion to ANSI/AWS D1.1; cited from 8.8.
Anti-creep (releveling)
On a hydraulic elevator, the requirement that the car not drift more than a set distance below the landing while parked, and the leveling action that automatically brings it back. Keeps the car sill lined up with the floor. Part 3.26.3.
Anti-slide device
Same thing as the antislide device: raised objects fastened to the deck of a high-deck balustrade to stop people (often children) sliding down it. At least 50 mm tall, with spacing rules in 6.1.3.3.12. See Antislide device.
Antislide device
Raised bumps along the top of a high-deck balustrade that prevent passengers (often children) from sliding down. Minimum 50mm tall, no sharp edges, spacing rules in 6.1.3.3.12.
ASME A17.1
The U.S. Safety Code for Elevators & Escalators, published by ASME and harmonized with Canada's CSA B44. See the Industry Associations reference .
ASME (American Society of Mechanical Engineers)
U.S. professional society that publishes the A17.x elevator and escalator safety codes. ASME A17.1 is the U.S. edition; CSA B44 is the Canadian companion.
ASTM E84
Surface burning characteristics test from ASTM International. Measures flame spread and smoke development of building materials. One of four flame-spread tests accepted for nonmetallic step/pallet components per 6.1.3.5.1.
ASTM (ASTM International, formerly American Society for Testing and Materials)
International standards body for materials and testing. ASTM E84 is one of the flame-spread tests acceptable for nonmetallic step/pallet components.
Authority Having Jurisdiction (AHJ)
Whoever actually enforces the code where the equipment is: the provincial safety authority, the state elevator board, the city. Where law makes the code mandatory, the AHJ is the regulatory authority. The code says what; the AHJ says what applies here, and their interpretation is the one that counts.
AWS (American Welding Society)
U.S. welding industry standards body. ANSI/AWS D1.1 is the structural welding code; ANSI/AWS D1.3 covers sheet steel. Both cited from 8.8.

B

Balustrade
The side wall of an escalator or moving walk, required on each side: interior panels, skirt panels, decking, and newels, with the handrail running on top. The handrail rides on it but is not technically part of it.
Belt driving machine
An indirect driving machine that sends the motor's power through a belt instead of gearing it straight to the sheave.
Belt-type treadway
A moving walk constructed as a continuous belt. Splice quality and slotting rules in 6.2.3.6. Slope, treadway width, and roller-bed deflection rules apply.
Big wheel
The handrail drive wheel.
Blind hoistway
A stretch of hoistway with no landing openings, common where an elevator serves a lobby and then a tower with several floors skipped. It drives extra requirements for getting people out.
Brake rated load
The load that the brake must be capable of stopping (running) and holding (stopped). Calculated per 6.1.3.9.3 using the escalator's width, angle, rise, and a defined loading factor.
Broken step chain device
Stops the escalator if a step chain breaks or goes badly slack, detected through the tension carriage's movement.
Broken treadway device
On a moving walk, cuts power to the driving machine if the connection between the pallets fails. It is the treadway's equivalent of the broken step chain device.
Buffer
A device in the pit that stops a descending car or counterweight that travels past its normal limit by absorbing or dissipating the impact. It's the last cushion at the bottom. Two common kinds: oil and spring. Part 2.22.
Buffer, oil
An oil-filled (hydraulic) buffer that soaks up energy as fluid is forced through orifices, giving a controlled stop. Its stroke must bring a car or counterweight striking at 115% of rated speed to rest at an average deceleration no greater than 9.81m/s² (32.2ft/s²) (2.22.4.1.1). Used on faster units. Oil buffers in general: 2.22.4.
Buffer, spring
An energy-accumulation buffer that stops the car or counterweight by compressing a spring. Must support twice the weight it protects without bottoming out (2.22.3.2.1), and go solid only at three times that weight (2.22.3.2.2). Used on slower units. Spring buffers in general: 2.22.3.
Buggy switch
The step upthrust device on an escalator.
Bumper
A solid end stop, and in code terms not a buffer at all: the word covers anything other than an oil, spring or elastomeric buffer used to stop a descending car or counterweight past its normal limit.

C

C22.1 (CSA C22.1)
The Canadian Electrical Code. In Canada, all electrical equipment and wiring on the escalator/moving walk must conform to CSA C22.1 (NFPA 70 is the U.S. equivalent).
Cab
The car. Everyone says cab; the code says car.
Callback
An unscheduled visit between regular maintenance because something went wrong. Callback rate is the single most useful number for judging whether a maintenance contract is working.
CAN/CGSB-12.1
Canadian General Standards Board standard for Tempered or Laminated Safety Glass. Canada's spec for tempered/laminated safety glass; one option for glass balustrades in Canadian jurisdictions per 6.1.3.3.3.
CAN/CGSB-12.11
Canadian General Standards Board standard for Wired Safety Glass, the older-style glass with embedded wire mesh. One of the CGSB glazing options accepted for balustrades per 6.1.3.3.3.
CAN/CGSB-12.12
Canadian General Standards Board standard for Plastic Safety Glazing Sheets: polycarbonate, acrylic, and similar materials used as glazing. Accepted alternative for plastic balustrades per 6.1.3.3.3.
CAN/CSA-S16.1-09
Canadian Standards Association's limit states design code for steel structures. Canada's structural-steel design rules for the escalator truss and supports per 6.1.3.10.1.
Car
The load-carrying unit of an elevator: the enclosure (cab) passengers or freight ride in, including its platform, walls, and door or gate. It rides the guide rails inside the hoistway. Part 2.14.
Car call
A destination-floor button pressed from inside the car, as opposed to a hall call made from a landing.
Car frame (sling)
The structural steel frame that carries the car platform and enclosure, transmits the load to the suspension means, and holds the car safety. Often called the 'sling.' Part 2.15.
Car lantern
The light and tone inside the car showing which way it is about to travel. The landing version is the hall lantern.
Car-direction indicator
A visual-only signal showing which way the car is going. No chime, and that is what separates it from a lantern.
Carriage switch
The broken step chain device, named after the tension carriage it watches.
CAT (Certified Accessibility Technician)
NAEC's two-year credential for technicians who work on accessibility devices and residential lifts. Not the same thing as CAT1/CAT5 periodic testing.
CAT1 / CAT5
Categorized safety tests required at set intervals (roughly annual for CAT1, roughly every five years for CAT5). This is more rigorous, equipment-down testing that costs a building real downtime and money.
CECA (Canadian Elevator Contractors Association)
The Canadian counterpart to NAEC, founded 1972. A non-profit representing independent contractors and suppliers; works on the CSA B44 code, U.S./Canada harmonization, labour matters, and apprenticeship.
CET (Certified Elevator Technician)
NAEC's four-year technician training and certification program. A non-union credential, complementary to the NEIEP apprenticeship route.
CFR (Code of Federal Regulations)
The codification of U.S. federal regulations. 16 CFR Part 1201 (architectural glazing) is cited for glass/plastic balustrades as an alternative to ANSI Z97.1.
CGSB (Canadian General Standards Board)
Canadian standards body. The CAN/CGSB-12.1, 12.11, and 12.12 glazing standards are cited as alternatives for glass/plastic balustrade material.
Clutch (vane)
The part on the car door that grabs the hoistway door's rollers so both doors move together. On power-operated sliding doors only the car has a door motor, and each landing door is opened through the clutch. Swing doors and many freight doors work differently.
Comb plate
The toothed plate at the top and bottom of an escalator where the moving steps flatten out and mesh with fixed teeth. One of the main places shoes and feet get caught, along with the gap between the step and the skirt.
Comb-pallet impact device
Moving walk equivalent of the comb-step impact device. Per 6.2.6.3.11. Same protocol: detects horizontal or vertical force on the combplate and cuts power.
Comb-step impact device
Safety device that cuts power to the motor and brake when defined horizontal or vertical forces are applied to the combplate, catching a foot, package, or wedged object before it gets dragged into the comb. Required by 6.1.6.3.13. Not the same as the comb plate itself.
Combplate
The comb-toothed metal plate at the entry and exit of every escalator and moving walk. Its teeth mesh into the slots of the step tread (or pallet) so there's never an open gap at the landing.
Compensation chain / cable
Heavy chain or cable hung below the car and counterweight on taller rises to offset the changing weight of the hoist ropes as the car travels.
Controller
The control system that governs dispatching, speed, and floor leveling. It is the "brain" of the elevator.
Counterweight
The balancing weight that hangs opposite the car on a traction elevator, connected by ropes over the sheave. It offsets the car's weight plus part of its load so the machine only lifts the difference. Built from stacked weight sections in a frame, riding its own guide rails. Part 2.21.
Counterweight displacement device
A device required on a qualifying elevator in a seismic-zone building that detects the counterweight shifting off its guide rails during an earthquake. One of the pieces of equipment 8.4.10.1.1 requires alongside the seismic detection device. Part 8.4.
Crosshead
The top beam of the car frame. Usually where the data plate lives, so it's the first place an inspector looks for the elevator's capacity and speed.
CSA B44
The Canadian safety code for elevators & escalators, harmonized with ASME A17.1, often written “ASME A17.1 / CSA B44.” See the Industry Associations reference .
CSA B44.1
Canadian companion to ASME A17.5, the listing and certification standard for elevator/escalator electrical equipment. Cited in 6.1.7.4.2: all electrical equipment installed on the unit must be listed and labeled per CSA B44.1 / ASME A17.5.
CSA W47.1
Canadian Standards Association's certification standard for companies that weld steel. Canada's qualification scheme: a welding company must be CSA W47.1 certified before its welders can perform code-required welds on the escalator (8.8).
CSA W59
Canadian Standards Association's welded steel construction standard. Canada's design and procedure equivalent of AWS D1.1. Cited from 8.8 for welded escalator components in Canadian jurisdictions.
CSA (Canadian Standards Association)
Canadian standards-development organization. Publishes CSA B44 (the Canadian elevator and escalator code, harmonized with ASME A17.1), CSA C22.1 (the Canadian Electrical Code), and many other Canadian standards.
CWT
Counterweight, written on drawings and said out loud as “C-W-T”.
Cylinder
On a hydraulic elevator, the fixed tube that holds the pressurized fluid and guides the plunger. The plunger rides inside it. Part of the jack assembly. Part 3.18.

D

Dashpot
An oil buffer.
Data plate
The plate stating the elevator's rated load and speed. If it's missing or unreadable, the unit can't be properly inspected or loaded.
Deck (decking)
The capping members of the balustrade. A high deck sits just below the handrail stand and a low deck sits just above the skirt. Either can have an interior section, an exterior section, or both.
Deck barricade
A barrier on the outer deck, at both the top and bottom of the escalator, that stops people climbing onto or sliding down the deck. Required on low-deck exterior balustrades where the outer deck is wider than 125 mm, and it reaches to about 100 mm below the top of the handrail. Rules in 6.1.3.3.13.
Deck lid
A landing plate or access plate on an escalator.
Deflector sheave
A secondary sheave that redirects the hoist ropes so they land correctly on the drive sheave or the counterweight: steering for the ropes, not driving them.
Demarcation
The yellow striping on the back and sides of each escalator step (sometimes backed by under-step lighting) that visually separates one step from the next so riders can see where a step ends. The material counts as a nonmetallic insert; dimensions in 6.1.3.5.6.
Designated level
The floor chosen as the one that best serves firefighters and rescue crews, usually the main lobby. It is where Phase I recall sends the cars.
Destination dispatch
A lobby system where riders enter their destination floor before boarding, letting the controller group people heading to the same floors into the same car to cut wait and ride time.
Door interlock
Another name for the hoistway door interlock: a lock-and-switch on the landing door that keeps the car from running unless that door is closed and locked, and keeps the door from being opened from the landing unless the car is at that floor. The car door is proved closed separately. See Interlock (hoistway door interlock).
Door operator
The motor and linkage on top of the car that drives the car doors and, through the clutch, drags the hoistway doors open and closed with them.
Door restrictor
A device that stops the car doors being forced open unless the car is in the door zone. It's what keeps a trapped passenger from opening the doors into a blank wall or a shaft.
Door zone (landing zone)
The short band above and below a floor where the car is close enough to level for the doors to be allowed to open.
Downtime
How long a unit was actually unavailable. Worth tracking separately from callback counts: ten quick resets and one three-week outage are very different problems.
Drive chain
The chain from the drive machine to the main drive shaft. It has its own broken-chain protection, separate from the step chains.
Drive-chain device
Per 6.1.6.3.4. When the driving machine connects to the main drive shaft via chain, this device cuts power if the chain disengages from its sprockets.
Driving machine
The power unit that moves the equipment. On elevators: the motor, brake, and (on geared units) gearing driving a sheave or drum. Traction and winding-drum are the two main types (Part 2.24). On escalators: the motor, gearing, and coupling or chain driving the main drive shaft. A motor can't drive more than one machine, and a machine can't run more than one escalator (6.1.5.2). One escalator can still have several machines.
Dumbwaiter
A small freight-only elevator with a car too small to carry people, used to move materials between floors. Covered by Part 7.
Dynamic skirt panel
A skirt panel that moves with the steps instead of staying stationary. Reduces the loaded-gap entrapment risk. Geometry and connection rules in 6.1.3.3.7.

E

ECA (Elevator Contractors of America)
The U.S. employer group for independent elevator contractors. It negotiates its own national agreement with the IUEC, separate from the one NEBA negotiates for the large manufacturers.
ECO (Energy-saving mode)
Industry shorthand for an escalator's variable-speed feature: the unit slows when no one's riding and accelerates to full speed when a passenger approaches. Code rules in 6.1.4.1.2.
EESF (Elevator Escalator Safety Foundation)
The industry's public-safety charity: a council organised in 1989 that became a foundation as its first program, Safe-T Rider, launched two years later. Runs rider-education programs like Safe-T Rider and National Elevator Escalator Safety Awareness Week each November.
EIWPF (Elevator Industry Work Preservation Fund)
A labour-management fund created under the IUEC national contract to protect and promote bargaining-unit work.
Electrical protective device
Code term for the safety devices that detect a fault and cut power to the motor and brake: 2.26.2 for elevators, 6.1.6.3 for escalators (16 separate devices there). Default reset is manual.
EMC (Electromagnetic Compatibility)
The discipline of designing electronics so they aren't disturbed by nearby electrical equipment, and don't disturb it either. The escalator controller's EMC tolerance is verified per ISO 22200 and EN 12016 in 6.1.7.4.3.
Emergency brake (escalator)
A brake acting on the main drive shaft itself, independent of the normal drive brake. It catches the failure the normal brake can't: the drive chain letting go.
Emergency exit (car top)
The hatch in the car ceiling. It must open from the car top without special tools, and it may also open from inside the car with a Group 1 security key (2.14.1.5.1(c)). Not a passenger escape route: trained rescuers use it, and passengers should stay put.
Emergency stop button / stop switch
The manual kill for the unit: operating it cuts power to the driving-machine motor and brake (on some escalators it first brings the unit down with dynamic braking, 6.1.6.3.1). On an escalator it is the red mushroom-head button at each landing; on an elevator the equivalents are the in-car stop switch and the pit switch. You will hear e-stop, mushroom button, kill switch and pit stop for the same control.
EMI (Electromagnetic Interference)
Electrical noise from one piece of equipment that can disturb another. Sources include motor drives, radio transmitters, and switch-mode power supplies. EMC testing exists to verify the controller tolerates expected EMI.
EN 12016 (EN 12016:1998)
European EMC test standard for elevator and escalator equipment; the current edition is EN 12016:2013. Control equipment tested to the 1998 edition doesn't need retesting under ISO 22200 if it was tested before one year after the effective date of A17.1-2016/B44-16 for escalators (6.1.7.4.3), or of A17.1-2013/B44-13 for elevators (2.26.4.4).
EN (European Norm, Standard)
Prefix for European standards published by CEN/CENELEC. EN 12016 is the European EMC test standard for elevator and escalator equipment (current edition 2013). B44 tests control equipment to ISO 22200 instead, and accepts older testing to EN 12016:1998.
Entrapment
An incident where a passenger is stuck inside a stalled car, distinct from an injury; most entrapments resolve with no one hurt.
Escalator deck (decking)
The members capping the balustrade across its width. A high deck sits just below the handrail stand and a low deck just above the skirt panel; each can have an interior section, an exterior section facing away from the unit, or both. Part of the balustrade, not the skirt.
Escalator rise
The vertical distance from the lower landing to the upper. It drives the step count and, from the 2022 edition, whether an auxiliary brake is required (rise over 6 m on units without dynamic braking, 6.1.5.3.5); it does not set the number of flat steps.

F

Factor of safety
The ratio of a part's ultimate (breaking) strength to its working stress under maximum static load. It's a margin, not a load multiplier. A factor of 5 means the part is five times stronger than the stress it normally sees. The code sets different minimums for different parts and different equipment. On escalators: 5 for steps, 8 for steel or bronze drive parts, 10 for cast iron drive parts and power-transmission members (6.1.3.10). On elevators the figure depends on the part: suspension members are sized from the table in 2.20.3, which rises with rated speed, and machines and their components carry their own factors under 2.24.3.
Fail-safe
A design principle where a failure (a broken wire, lost power, a stuck part) drives the system to a safe state (typically stopping the car) rather than an unsafe one. The principle behind the code's single-fault wiring rules.
Group 1 / 2 / 3 Security (keys)
The code’s classification for how tightly a key must be controlled. Section 8.1 sorts the keys used on elevators and escalators into security groups (there is also a Group 4, “Other”), and the clause covering each device names the group its key has to belong to. For example, the key that unlocks a hoistway door from outside must be Group 1 Security (2.12.6.2.4), while the firefighters’ FEO-K1 key is Group 3. The notes under 8.1.2 to 8.1.5 index which requirements fall in each group, but the binding rule is in the clause for the device.
FEO-K1
The single standardized firefighters' emergency-operation key that operates Phase I recall, Phase II in-car operation, and the standby-power selector. A restricted 'Group 3 Security' key. Part 2.27.
Final terminal stopping device
The backup travel limit: an independent device that removes power from the driving machine and stops the car if it runs past the normal stop at the top or bottom landing. Deliberately independent of the normal terminal stopping device, and set to act only after it should have. Part 2.25.3.
Finger guard
Small piece of metal or plastic above the point where the handrail enters the newel, preventing fingers from being pulled in along with the handrail. Required by 6.1.3.4.3.
Fireman's service (Phase I / Phase II recall)
An emergency operating mode: Phase I automatically recalls cars to a designated floor when smoke/fire is detected; Phase II lets firefighters take manual in-car control once on scene.
Flat steps
The level steps at the top and bottom of every escalator where passengers board and exit: at least 2 and no more than 4 per 6.1.3.6.5. The clause sets no other condition; the count is not tied to speed or rise. They give riders time to get their footing before the incline.
Form, fit, and function
The test for whether swapping an escalator or moving walk part counts as an alteration. If the new part is interchangeable with the old one in form, fit AND function, it's a replacement, not an alteration (8.7.6.1.1 for escalators, 8.7.6.2.1 for moving walks; see 8.6.3.1). Adding a component that wasn't part of the original design is always an alteration.
Full-load test
Running and stopping the car loaded to its rated load to prove brake, machine and safeties perform under real load. Part of what makes CAT testing disruptive and expensive.
Full-service contract
A maintenance contract covering both labour and parts for repairs, as opposed to an oil-and-grease contract that only covers routine lubrication and inspection.

G

Gate switch
The electrical contact proving the car door or gate is closed. Nothing should move on automatic operation until it's made up.
Gear reducer
Gearbox between the motor and the main drive shaft. If the motor-to-reducer connection isn't a continuous shaft, coupling, or toothed gearing, the brake must be on the reducer or main shaft (6.1.5.3.1(e)).
Geared machine
A traction machine where the motor drives the sheave through a gearbox (usually worm gear). Slower and noisier than gearless, and the gearbox is a real maintenance item.
Gearless machine
A traction machine where the sheave is driven directly by the motor, no gearbox. Standard on high-rise and high-speed elevators, and on most modern machine-room-less units.
Gibs
The small guides on the bottom edge of a door panel that ride in the sill groove, under both the hall and car doors. Worn gibs let a door rattle, drag, or jump out of the sill.
Gov
The overspeed governor.
Government Services (Newfoundland and Labrador)
The Newfoundland and Labrador department that oversees elevating devices. It has been renamed repeatedly (Service NL, then Digital Government and Service NL, then Government Modernization and Service Delivery), and as of 2026 the province’s own site calls it Government Services. The part that does not move is the office: the Engineering and Inspections Division, and the Chief Inspector of Amusement Rides and Elevating Devices. Ask for the Chief Inspector, not the department.
Governor (overspeed governor)
Another name for the speed governor: the continuously running device that monitors car speed and trips the car safety to grip the guide rails if the car exceeds its overspeed threshold.
Governor trip test
Deliberately tripping the overspeed governor to confirm it grabs at the right speed and sets the safeties. Nobody finds out the governor is seized at a good moment.
Group 2 Security
The key group for authorized personnel, defined in 8.1.3. It covers elevator machine-room and control-room access doors, and on escalators the starting switch key (6.1.6.2.1(d)) and side access door key (6.1.7.3.3).
Guide rail
The steel rails running the height of the hoistway that keep the car and counterweight travelling in a straight line without swaying or twisting, and that the safety grips to stop the car. Part 2.23.
Guide shoe
What keeps the car tracking the rails: either sliding shoes with replaceable inserts, or roller guides. Worn shoes are a common cause of a rough, noisy ride.

H

Hall call
The up/down button pressed at a landing to request a car, as opposed to a car call made inside the cab.
Hall door / landing door
The hoistway door, the one passengers see at each floor.
Hall lantern
The light and chime at a landing announcing which car is arriving and which way it's going, the signal that tells a waiting crowd where to stand.
Handling capacity
The share of a building's population the elevators can move in five minutes. Roughly 11-13% is expected of an office building, 5-7% of residential. Below that, people queue.
Handrail
The continuous moving loop (usually rubber) on top of each balustrade that riders hold. Must travel in the same direction and at substantially the same speed as the steps or pallets. Rules in 6.1.3.4.
Handrail drive belt (pressure belt)
The belt that drives the handrail by friction, pressing it against the drive wheel. It is not the handrail itself: a worn drive belt shows up as a handrail that slows, slips or stops while the steps keep running. Also called the pressure belt.
Handrail entry device
Safety device at each newel where the handrail enters the balustrade. Cuts power to the motor and brake if anything gets caught or approaches that entry point. Per 6.1.6.3.12.
Handrail inlet
The guarded point where the handrail disappears into the newel. Fitted with a device that stops the unit if something is dragged into it. It's a classic finger-entrapment location for children.
Handrail speed monitoring
Watches the handrail against the step speed and stops the unit if it drifts out of step. A handrail moving at a different speed to the steps pulls riders off balance.
Handrail speed-monitoring device
Device that monitors handrail speed against step speed. Triggers the audible alarm immediately at 15%+ deviation and cuts power if the deviation persists 2–6 seconds. Per 6.1.6.4.
HB (Horizontal Burn, 94 HB)
Lowest flammability rating in the ANSI/UL 94 series; tested horizontally. Nonmetallic step and pallet attachments (not wheels) must be 94 HB or better (6.1.3.5.1(b) for steps, 6.2.3.5.5(b) for pallets).
Headroom
Minimum vertical clearance above the step nose line, landing plates, and landings: 2,130mm (84in.) per 6.1.3.12. Ceiling renovations near the escalator can invalidate this.
Helper
The traditional term for an entry-level, pre-journeyperson worker on a crew, used more or less interchangeably with “apprentice” for generations. Some prefer “apprentice” as the more precise term for someone formally indentured and enrolled in NEIEP/CEIEP, but “helper” is still common in everyday shop talk and job postings. See How to Become an Elevator Mechanic .
Hoistway
The enclosed vertical shaft the elevator car and counterweight travel through, floor to floor. Also called the 'shaft.' Part 2.1.
Hoistway access switch
A key-operated switch at a landing that lets authorized personnel move the car slowly with the hoistway door open, for access to the car top or pit. Its use is tightly limited. Part 2.12.7.
Hoistway door
The door at each landing that closes off the hoistway opening. Must be closed and locked (proved by an interlock) before the car can run away from that floor. Part 2.11.
Hospital service
Attendant operation reserved for medical emergencies, where a staff member takes control of the car to move a patient. Not fire service, and not a general priority-call feature.
Hydraulic elevator
An elevator raised and lowered by a fluid-driven jack (a plunger in a cylinder) instead of ropes and a counterweight. Common in low-rise buildings. Governed by Part 3.
Hydraulic jack
The cylinder and plunger assembly that pushes a hydraulic elevator up. On older in-ground jacks, a buried cylinder that starts leaking is one of the most expensive repairs a building can face.
Hydraulic machine
The pump, motor, valves and piping that push pressurized fluid into the jack on a hydraulic elevator. The machine supplies the fluid; the jack (the cylinder plus the plunger inside it) turns it into lift.

I

IAEC (International Association of Elevator Consultants)
Membership group for independent vertical-transportation consultants (formerly NAVTP, the National Association of Vertical Transportation Professionals). Holds an annual Forum.
IBC (International Building Code)
The model building code published by the International Code Council. Several U.S. states do not adopt A17.1 directly. They adopt an edition of the IBC, and the elevator edition follows from whichever A17.1 that IBC points at. New York and New Jersey both work this way, which is why their entries on the code finder cite a building subcode rather than an elevator regulation.
ICC (International Code Council)
Publishes the International Building Code and the rest of the I-Codes. It does not write the elevator code itself; it is the route by which some U.S. jurisdictions adopt one.
Independent service
Takes a car out of the group so it only answers buttons pressed inside it, with the doors held open until someone asks it to go. What movers and hospital staff actually want when they say “lock the elevator off”.
Inspection control
Constant-pressure controls used during maintenance, repair, or inspection: the unit moves only while a finger is on the button. Not accessible to the public. Required by 6.1.6.2.2. Also called inspection operation.
Inspection operation
Slow-speed control used for servicing: from the car top or machine room on an elevator, from the machinery space or pit on an escalator. It overrides normal operation and disables automatic movement. Also called inspection control; mechanics call the control itself the running buttons or pendant.
Interlock (hoistway door interlock)
A combined lock-and-switch on a hoistway door that does two things: prevents the car from running unless the door is closed and locked, and prevents the door from being opened from the landing unless the car is at that floor. Proves 'closed AND locked.' Part 2.12.2.
Interval
The average wait between car departures from the lobby. Around 20-30 seconds is normal for an office building, 40-60 for apartments. It's what tenants actually experience as “the lifts are slow”.
ISO 22200 (ISO 22200:2009)
International EMC test standard for elevator and escalator control equipment. Replaces EN 12016 going forward and is what controllers must be tested to under 6.1.7.4.3.
ISO (International Organization for Standardization)
Independent international standards body. Publishes thousands of standards across industries; ISO 22200:2009 is the control-equipment EMC test that B44-22 cites in 6.1.7.4.3.
ITS (Inspection and Technical Services, Manitoba)
The branch of Manitoba Labour and Immigration that regulates elevators, escalators and other elevating devices in the province, under Schedule C of the Technical Safety Regulation (The Technical Safety Act). Not the Office of the Fire Commissioner.
IUEC (International Union of Elevator Constructors)
The union representing more than 30,000 mechanics, helpers, and apprentices who install, maintain, and service elevators and escalators across the U.S. and Canada.

J

Jack (hydraulic jack)
The hydraulic lifting assembly of a hydraulic elevator: the cylinder plus the plunger that rides inside it. Fluid pumped into the cylinder pushes the plunger up to raise the car. Part 3.18.
Jamb
The vertical frame piece on either side of a landing door opening.

L

Landing
A floor stop, where the car aligns with a building floor and the doors open.
Landing plate
The metal floor plate at each end of an escalator or moving walk, covering the machinery spaces. Also called a floor plate, cover plate, or deck lid. Removable for access, but in service it must be properly secured, free of tripping hazards, and provide a secure foothold per 8.6.8.14 / 8.6.9.12.
Leveling
The automatic fine-adjustment that lines the car floor up flush with the landing floor before the doors open.
Leveling zone
The short distance above and below a landing inside which the leveling device is allowed to move the car to bring it flush with the floor. Outside that zone it is not permitted to run.
Load-weighing device
A sensor that measures how much weight is in the car, used to bypass hall calls when full or detect an overload condition.
Loaded gap
The gap that opens between the step tread and the adjacent skirt panel when 110N (25lbf) is applied sideways. Current editions cap it at 5mm (6.1.3.3.5). A unit is held to the edition it was installed under, and plain CSA B44-00 used a fixed clearance limit instead, so check which applies. Inspectors check it; entrapment risk if exceeded.
LULA (Limited-Use / Limited-Application elevator)
A small, slow passenger elevator with reduced requirements, meant for low-rise and accessibility settings. Capped at 635kg (1,400lb), 1.67m² (18ft²) of car area, and 0.15m/s (30ft/min). Part 5.2.

M

Machine room
A dedicated, enclosed room that houses the driving machine and controller, separated from the hoistway. Access, headroom, lighting, and what may share the space are all regulated. Part 2.7.
Machine room (MR) / Machine-room-less (MRL)
A traditional elevator has a dedicated room housing the hoist machine and controller; an MRL design fits that equipment into the hoistway or a control cabinet instead, freeing up building space.
Machinery space
A space (inside or outside the hoistway) that contains machinery but isn't a full machine room. On MRL units the machine lives in a machinery space rather than a room. Section 2.7 covers these spaces too, with its own requirements for them.
Main drive shaft
The shaft at the top of the truss that drives the step or pallet chain. The step band and handrail drive both take their motion from it. Either directly connected to the driving machine or coupled by a separate drive chain, which triggers additional brake and redundancy rules in 6.1.5.3.2.
Maintenance
Routine examination, lubrication, cleaning, and adjustment of parts to keep a unit performing to code. Distinct from repair and replacement. Part 8.6.
Maintenance Control Program (MCP)
The written, on-site plan and records of all maintenance, repair, replacement, examination, and test work on a unit, required by 8.6.1.2.1. Must include manufacturer's instructions, callback records (8.6.1.4.2), and test procedures, and be available to the inspector. 'We do it when we get to it' is not one.
Missing step device
Stops the unit when a gap appears where a step should be, before that gap reaches the landing. On escalators with dynamic skirts, a second device does the same for a missing dynamic skirt panel, stopping the unit before the gap comes out from the balustrade (6.1.6.5(b)).
Modernization
A comprehensive upgrade of an aging elevator's major components (controller, machine, wiring, fixtures). It is a capital project, not routine maintenance.
Moving walk (travolator)
A horizontal or gently inclined conveyor for pedestrians, using pallets instead of an escalator's stepped treads.
MRL (Machine-Room-Less elevator)
An elevator with no dedicated machine room; the machinery and control equipment sit in small spaces inside the hoistway, the pit, or a shallow cabinet at a landing. The code applies its machinery-space and control-space rules to those locations.
MW (Moving Walk)
Shorthand for moving walk. A flat or slightly inclined people-mover, similar to a treadmill. Governed by Section 6.2 of Part 6 (parallel to 6.1 for escalators).

N

NAEC (National Association of Elevator Contractors)
Founded 1950; the largest vertical-transportation trade organization in North America. Serves independent contractors and suppliers, runs the big annual industry convention, and administers the CET and CAT certifications.
NAESA (National Association of Elevator Safety Authorities, International)
Non-profit of inspectors, contractors, and engineers focused on code enforcement. Certifies QEI inspectors to the ASME QEI-1 standard and runs code-update workshops across the U.S. and Canada.
NBCC (National Building Code of Canada)
Canada's model building code, adopted by provinces and territories. The elevator and escalator codes point to it for building and fire-protection matters, and some escalator rules change depending on whether the NBCC is enforced (e.g., remote stop buttons, 6.1.6.3.1). B44-16 also tied machine-room fire extinguishers to it (8.6.1.6.5); B44-22 dropped that condition.
NEBA (National Elevator Bargaining Association)
The U.S. employer group that negotiates the national collective bargaining agreement with the IUEC on behalf of its member companies. It tends to represent the larger shops, while ECA covers the smaller, independent side.
NEEA (National Elevator and Escalator Association)
The Canadian trade association of the major manufacturers (Woodbridge, ON), effectively the Canadian equivalent of NEII on codes, standards, and safety advocacy. Also acts as the employer bargaining agent for its four member companies in their IUEC negotiations.
NEI / NEIBP (National Elevator Industry Benefit Plans)
The pension and health benefits plans for IUEC members. The 'NEI' on benefits paperwork. Not the same as NEII (the trade association) or NEIEP (the training program).
NEIA
Not a real organization: there is no elevator or escalator body called “NEIA,” in North America or anywhere else. If you've seen it somewhere, it's most likely a mix-up with NEII, NEI/NEIBP (the industry's benefit plans), or NEIEP below. See the Industry Associations reference for the full explanation.
NEIEP (National Elevator Industry Educational Program)
The joint IUEC-employer apprenticeship and education program. Develops and runs the curriculum that trains union mechanics; apprentice applications go through neiep.org.
NEII (National Elevator Industry, Inc.)
The U.S. trade association for the major elevator and escalator manufacturers: Otis, Schindler, KONE, TK Elevator, Fujitec, Mitsubishi. Drives code positions, standards, safety, and government advocacy. Not 'NEIA', which is a common but wrong rendering.
NEMA 250 (NEMA 250)
NEMA's enclosure rating standard. 'Type 4' construction is watertight: it keeps out rain, windblown dust, and splashing or hose-directed water, and isn't damaged by ice forming on the outside. It is the minimum for electrical equipment on outdoor escalators (6.1.8.1.2).
NEMA (National Electrical Manufacturers Association)
U.S. trade association for electrical equipment makers. NEMA 250 defines enclosure ratings: Type 4 (watertight, including hose-directed water) is the minimum for outdoor escalator electrical equipment per 6.1.8.1.2.
Newel
The curved end section of the balustrade at the top and bottom of an escalator (or each end of a moving walk), where the handrail wraps around and enters or exits the balustrade.
NFG
No f’ing good. Shop shorthand scrawled on a tag or called down the hoistway for a part that is past saving. Not a diagnosis, just a verdict. You will hear it long before you hear “defective.” Credit: lepchaun415
NFPA 101 (NFPA 101, Life Safety Code)
The U.S. Life Safety Code. Defines 'noncombustible' and 'limited-combustible' materials, which Part 6.1.2 references for the truss enclosure's fire protection.
NFPA 255 (NFPA 255)
NFPA's surface burning characteristics test. One of four flame-spread tests acceptable for nonmetallic step/pallet materials (alongside ASTM E84, UL 723, CAN/ULC-S102.2).
NFPA 70 (National Electrical Code, NEC)
The U.S. electrical code. All electrical equipment and wiring on a U.S. elevator or escalator must conform to NFPA 70. CSA C22.1 is the Canadian equivalent.
NFPA (National Fire Protection Association)
U.S. fire-protection standards body. Publishes the National Electrical Code (NFPA 70), Life Safety Code (NFPA 101), and many other codes cited throughout Part 6.
No-load test
Running and stopping the car empty to confirm the brake, machine and safety devices still behave as they should. Quicker and far less disruptive than testing with weights in the car, so it comes round on its own schedule.
Normal terminal stopping device
The first travel limit: slows and stops the car at or near the top and bottom landings if normal stopping fails. It works independently of the normal stopping means and acts before the final terminal stopping device would. On cars rated 0.75 m/s (150 ft/min) or less it may also serve as the normal stopping means. Part 2.25.2.
Nudging
After the doors have been blocked too long, the buzzer sounds and the doors close slowly at reduced force. Deliberate behaviour, not a fault.

O

OEM (Original Equipment Manufacturer)
The original maker of the escalator or its components. OEM-spec parts carry the type tests and engineering tests the code requires (e.g., brake type test 8.3.6, step fatigue engineering test 8.3.11).
Oil buffer
A buffer that uses oil to absorb and dissipate the energy of a descending car or counterweight, rather than storing it the way a spring does. Mechanics call it a dashpot.
Oil-and-grease contract
A minimal maintenance contract covering routine lubrication and inspection only: repairs and parts are billed separately, unlike a full-service contract.
OSHA (Occupational Safety and Health Administration)
U.S. federal workplace-safety agency. California's Division of Occupational Safety and Health (Cal/OSHA) includes the state Elevator Unit, an example of a state-level regulatory authority.
Outdoor escalator
An escalator exposed to weather. Subject to 6.1.8 in addition to the standard rules: corrosion protection, NEMA 250 Type 4 electrical equipment, a precipitation cover, heating in cold climates, and weather-resistant drains.
Overhead
The height from the floor of the top landing up to the underside of the hoistway ceiling, slab or machine beams. Tight overhead is what usually kills a cheap modernization plan.
Overspeed governor
See Governor .

P

Pallet
The flat metal tread unit of a pallet-type moving walk. Links with adjacent pallets to form the running surface, the moving-walk equivalent of an escalator step. The alternative construction is a continuous belt. Rules in 6.2.3.5.
Pallet band
The moving-walk equivalent of a step band: every pallet plus the means connecting them, taken as one assembly.
Pallet-type treadway
A moving walk constructed of linked flat pallets. Subject to slotting, intermeshing, alignment, and fatigue-test rules in 6.2.3.5.
Part 9
A17.1 / B44's own bibliography of every external standard the code cites, with the applicable edition and a US / Canada / both jurisdictional column. When the code says 'see Part 9,' it's pointing to this bibliography to find the right standard for a given jurisdiction.
PE (Professional Engineer, licensed)
A licensed Professional Engineer. Part 8.7.1.5 requires PE design verification for welding, cutting, or splicing of support members (trusses, girders, tracks) during alterations.
Periodic inspection
Recurring inspection (typically annual; frequency set by the regulatory authority) of an in-service unit. Confirms ongoing conformance to the code. Items listed in 8.11.4.1.
Phase I (automatic recall)
The first stage of firefighters' service: a fire alarm (or the fire-service key) automatically sends the car to a designated level, opens its doors, and holds it there out of public use. Part 2.27.3.
Phase II (in-car firefighter operation)
The second stage: once recalled, a firefighter takes manual control from inside the car using the FEO-K1 key, running it under their direct command. Part 2.27.3.
Pit
The part of the hoistway below the bottom landing, where the car travels at its lowest point. Holds the buffers and other equipment, and must provide safe access, a stop switch, lighting, and defined bottom clearances and refuge space. Part 2.2.
Pit ladder
The fixed ladder giving safe access into the pit. A missing or non-compliant one is a routine inspection write-up.
Platform
The floor structure of the car that carries the load, mounted on the car frame. Its area is limited by the rated load to prevent overloading. Part 2.15 / 2.16.
Plunger (ram)
The steel rod of a hydraulic jack that rides inside the cylinder and pushes the car up as fluid is pumped in. Mechanics usually just say 'ram.' Part 3.18.
Plunger gripper
A fall-arrest device on a direct-acting hydraulic elevator that clamps the plunger to stop and hold the car if it descends too fast, taking the place of a rail safety where the car has none. Part 3.17.3.
Position indicator
The display showing where a car is. In the lobby it manages expectations; in the machine room it's a diagnostic.
Preventive maintenance (PM)
The scheduled work meant to stop failures happening, as opposed to fixing them afterwards. It's the part of a contract most easily quietly reduced.
Probationary Helper
The first defined stage of the union apprenticeship ladder under some IUEC locals' agreements, e.g. IUEC Local 82's British Columbia & Yukon agreement, where it means a newly hired worker with no elevator experience, capped at 6 months, paid 50% of the Mechanic's rate. Exact terms vary by local. See How to Become an Elevator Mechanic .

Q

QEI (Qualified Elevator Inspector)
The standard certification for elevator and escalator inspectors, governed by ASME QEI-1 and issued by NAESA among other bodies. Inspectors performing acceptance and periodic inspections typically must hold it and be authorized by the regulatory authority.
QEI-1 (ASME QEI-1)
ASME QEI-1: Standard for the Qualification of Elevator Inspectors. Per 8.10.1.1.3, the inspector performing an acceptance inspection must meet these qualifications.

R

Ram
The plunger of a hydraulic jack.
Rated load
The load a unit is designed and permitted to carry: the number on the capacity plate, a design limit, not a target. On elevators, the load the unit lifts at rated speed (Part 2.16). On escalators, the design load used to size the truss, drive, brake, and steps, from formulas in 6.1.3.9.
Rated speed
The speed a unit is designed to run at; measured speed is compared against it during testing. For an elevator, the up-direction speed carrying rated load. For escalators, measured along the step centerline: maximum 0.5m/s (100ft/min) per 6.1.4.1.1; 0.7–0.9m/s for moving walks depending on slope.
RBQ (Régie du bâtiment du Québec)
Quebec's regulatory authority for building safety, including elevators and escalators.
Recall
Automatically sending a car to a designated floor in response to an event: fire alarm, power failure, or an emergency-power condition.
Recall level
The floor cars are returned to under Phase I recall, normally the designated level, or the alternate level when the alarm is at the designated level itself.
Refuge space
A protected clear volume in the pit (and on the car top) that stays open even if the car reaches its lowest point, giving a worker a place the car can't crush. The code sets an absolute minimum size for it. Part 2.4.
Regenerative drive
A motor drive that feeds braking energy (e.g., a descending loaded car) back into the building's electrical grid instead of dissipating it as heat. Some owners specify it to save energy.
Regulatory authority
The body responsible for administering and enforcing the law that governs elevating devices in a given jurisdiction. B44 defines it as its own term; where law makes the code mandatory, the regulatory authority is the Authority Having Jurisdiction (AHJ). Varies by province in Canada and by state (or municipality) in the U.S.
Releveling (anti-creep)
Automatic small corrections that bring the car back level with the landing after it drifts: from rope stretch, or on hydraulics from fluid leak-down as oil cools and the car settles. Closely tied to anti-creep on hydraulic units. Part 2.26.1.6 / 3.26.3.
Relief valve
On a hydraulic elevator, the pressure-safety valve that bypasses fluid back to the tank so system pressure can't exceed a set limit. Installed so it can't be shut off, and its setting is checked on the required test schedule. Part 3.19.
Repair
Reconditioning or renewing parts to keep a unit in code compliance. More than routine maintenance but less than an alteration. Distinct from maintenance and replacement. Section 1.3.
Replacement
Swapping a device or component for one that is basically the same as the original ('form, fit, and function'). A true like-for-like replacement is not an alteration. Section 1.3.
Retiring cam
An older mechanism that physically extends to release each hoistway door lock as the car arrives, then retracts. Still common on older installations.
Reversal stop device
Safety device that detects an unintended reversal of an ascending escalator and cuts power to the motor and brake. It is the protection against a loaded up-escalator being driven backwards by its own passengers. Required by 6.1.6.3.8.
Riser
The vertical front face of an escalator step. Cleated so its vertical ridges mesh with the slots in the adjacent step's tread, preventing open gaps at the unfold/fold zones.
Rope (hoist rope)
The steel wire ropes that suspend the car and counterweight over the sheave in a traction elevator.
Rope gripper
A device that clamps the hoist ropes to stop the car, commonly fitted during modernization to satisfy unintended-movement and ascending-overspeed requirements without replacing the machine.
Roping (1:1, 2:1)
How the ropes are reeved between machine, car and counterweight. 2:1 roping halves the speed the car moves relative to the rope, which lets a smaller machine lift a bigger load.
Route
The set of buildings one mechanic covers. Route size is the quiet variable behind response times: the contract can say anything, but a stretched route shows up as slow callbacks.
Runby
The extra travel a car or counterweight has beyond a terminal landing before it would strike its buffer. It's designed-in overtravel margin at the top and bottom, not spare capacity. Part 2.4.
Running gear
The moving assembly of steps or pallets and their chain that travels along the truss's track system. The code's definition is wider: all the components of an escalator that move along the tracks. If something fails, the track system has to keep the running gear inside the truss (6.1.3.7).
Rupture valve (velocity fuse)
A hydraulic safety that slams shut if oil suddenly rushes out of the jack (as it would if a line burst), so the car settles instead of dropping.

S

Safety (car or counterweight safety)
A mechanical device on the car (or counterweight) that grips the guide rails to stop and hold it in an overspeed, free-fall, or slack-rope condition. Sorted into Types A, B, and C by how it slows the car. Part 2.17.
Safety edge / photo eye
The door protection that reverses a closing door: a physical bumper on older units, an infrared curtain on newer ones. First thing to suspect when doors reopen for no reason.
Safety gear
A mechanical device on the car (and sometimes counterweight) that clamps onto the guide rails to stop it if the governor detects overspeed or a free-fall condition.
Safety zone
The clear area at the entry and exit landings, kept free of obstacles. Width: distance between handrail centerlines plus 200mm. Length: twice that distance from the end of the newel. Absolute minimums per 6.1.3.6.4.
Safety, Type A
An 'instantaneous' safety: it grips the rails hard and stops the car in a very short distance, using nothing to soften the grab. Allowed only on slow units, up to 0.75m/s (150ft/min) (2.17.8.1). What it is: 2.17.5.1.
Safety, Type B
A safety that applies a limited, controlled rail pressure so the stopping distance stays reasonable for the car's weight and speed. Used across a wide speed range; stopping distances are tabulated against governor tripping speed. Part 2.17.5.2.
Safety, Type C
A Type A instantaneous safety working together with oil buffers between the car frame and the safety plank. The buffers' stroke supplies the controlled stopping distance. Part 2.17.5.3.
SCC (Safety Codes Council, Alberta)
Alberta's Safety Codes Council. It isn't the body that hands elevating-device safety to AEDARSA; the Government of Alberta does that. The SCC certifies AEDARSA to do in-service inspections on elevating devices.
Seismic detection device
A device that senses ground motion. What it does depends on the equipment. On an escalator or moving walk it removes power from the driving-machine motor and brake (8.5.4). On elevators it starts earthquake operation: cars that are moving go to the nearest available floor, open their doors and shut down (8.4.10.1.3). At least one per elevator group (8.4.10.1.1).
Seismic operation
What elevators do in an earthquake. When the seismic detection device trips, moving cars go to the nearest available floor, open their doors and shut down. If the counterweight displacement detector trips, the car makes an emergency stop, then creeps away from the counterweight at no more than 0.375 m/s (75 ft/min) to the nearest floor (8.4.10.1.3, 8.4.10.1.4). A counterweight that has come off its rails is the real danger.
Selector
The device (older units use a mechanical tape/wheel; modern units use encoders) that tracks the car's exact position in the hoistway for leveling and dispatch.
Sheave
A grooved pulley the suspension ropes run over. On a traction machine, the drive (traction) sheave grips the ropes by friction to move the car. Part 2.24.2.
Shutdown
A unit out of service and unavailable to the building, distinct from a callback, which is the visit. One callback can cause no shutdown at all; one shutdown can last weeks waiting on a part.
SIL (Safety Integrity Level)
A rating (1 to 4, with 4 the most stringent) for how dependable an electronic or programmable safety function must be. Comes from the external IEC 61508 series. Section 1.3.
Sill
The threshold plate at a car or landing doorway that the doors slide across.
Simplex / duplex / triplex
How many cars are working as one group: one, two, or three. It's the first thing that determines what service a building can expect at peak.
Skirt deflector
The brushes running along the skirt panel that keep feet, bags and clothing away from the gap between step and skirt. Mechanics call them skirt brushes.
Skirt deflector device
Optional rigid or flexible element parallel to the skirt panel that steers feet and clothing away from the loaded gap. Geometry rules in 6.1.3.3.10. Allows a higher step/skirt index limit.
Skirt obstruction device
Stops the escalator if an object becomes caught between the step and the skirt as the step approaches the combplate. That gap is the trap that catches shoes and loose clothing right at the end of the run.
Skirt panel
The vertical panel on each side of the escalator step band, between the balustrade interior and the steps. Must be smooth, extend at least 25mm above the tread nose line, and deflect less than 1.6mm under a 667N load (6.1.3.3.6).
Slack rope switch
A switch that cuts power if the hoist ropes go slack: the sign that the car has landed on something, or a drum machine has kept paying out rope with nowhere to go.
Sling (car frame)
The steel frame the car sits inside. The platform, safeties and ropes all attach to it. The cab you stand in is really just a finished box bolted into the sling.
Speed governor
An elevator device: continuously running, it monitors car speed and trips the car safety when the car goes too fast. It's the spinning watchdog that tells the safety when to grab (Part 2.18). Escalators have no car safety and no governor in this sense; their overspeed protection is the speed-monitoring device, which cuts power to the driving-machine motor and brake once speed exceeds rated by more than 20% (6.1.6.3.2). Where an escalator does have a mechanical speed governor, it is tested at periodic inspection by tripping it by hand (8.6.8.15.5).
Speed-monitoring device
Electrical safety device per 6.1.6.3.2 that cuts power if the unit's speed exceeds rated speed by more than 20%. Manual-reset.
Splice
A joint in a handrail or belt-type treadway. The two have different rules. A handrail splice must leave the joint free of any pinching effect (6.1.3.4.4); bumps and sharp tapers are the usual ways it fails that test. A belt splice must leave a continuous, unbroken treadway surface with the same characteristics as the rest of the belt (6.2.3.6.1).
SSPI (Step/Skirt Performance Index)
Combined friction-and-clearance figure of merit used to judge how safely the step interacts with the adjacent skirt panel. Computed from the polycarbonate-specimen friction coefficient and the step-to-skirt clearance under controlled load. Every escalator in service is tested, except units with dynamic skirt panels (6.1.3.3.9). The installation era and the code edition in force in the jurisdiction set the thresholds it must meet, and whether the loaded-gap limit applies at all, never whether the test happens. Test procedure: 8.6.8.15.19. Pass thresholds: 8.6.8.3.3.
Standby power operation
How the group behaves on generator power, when the building usually can't run every car at once: cars are brought down and returned to service in a set order.
Static control
Solid-state motor control. Because there's no contactor opening the motor circuit by default, code requires two redundant power-removal devices, at least one electromechanical (6.1.6.10.4).
Step
One of the linked moving tread units that form the running surface of an escalator, with grooves that mesh with the comb plate at each end. Tread depth at least 400mm, rise no more than 220mm, width 560–1,020mm per 6.1.3.5.2.
Step band
All the steps plus the means connecting them, taken as one assembly. When someone says the step band is out, they mean the whole loop, not a single step.
Step chain
The chains that connect the steps and pull the step band along the truss tracks. Cast iron links are prohibited (6.1.3.11), and a broken step chain must trigger the stop device in 6.1.6.3.3. Stretch and wear are measured, not eyeballed: a worn chain changes step spacing and comb engagement.
Step lateral displacement device
Safety device required on curved escalators: cuts power to the motor and brake if a step is pushed too far sideways by a failure in its lateral support (6.1.6.3.14). It has to be reset by hand.
Step level device
Safety device that detects a step dropping out of line (downward displacement of 3mm or more at the riser end) and stops the escalator before that step reaches the combplate, so a sagging or broken step never reaches riders. Per 6.1.6.3.11.
Step nose line
The line along the leading edge of each step's tread. Used as a reference for vertical-clearance dimensions including headroom (2,130mm above), handrail height (900 to 1,000mm above under B44-16; 900 to 1,100mm under B44-22, 6.1.3.4.5), and skirt height.
Step roller
The rollers under each step that ride along the truss track system. If the support rollers sit outside the width of the step, a provision must keep the step from falling into the interior if a roller fails (6.1.3.5.8). Flat-spotted or seized rollers give the classic thump-thump on an otherwise healthy unit.
Step upthrust device
Safety device that detects a step lifting where it shouldn't (upward displacement of more than 5mm at the riser end near the lower landing, usually from something jammed under the step band) and stops the escalator. Per 6.1.6.3.9. Mechanics call it the buggy switch.
Stop switch
Manually opened/closed switch labeled 'STOP/RUN' with positively-opened contacts. Required in each machinery space except the one with the main line disconnect switch, and in other spaces that give access to the interior (6.1.6.3.5), and next to inspection controls (6.1.6.3.15).
Suspension (suspension means)
The code's collective word for whatever actually holds the car up: steel wire ropes, aramid fiber ropes, or coated steel belts (2.20.1). Worth knowing because “rope” is the habit and belts are common on machine-room-less units, so a requirement written about suspension applies to your belts too. See Rope (hoist rope) .
Suspension means
What the car and counterweight hang from (steel wire ropes, aramid fiber ropes, or noncircular coated-steel members), attached to the car frame. Carries a required safety margin (factor of safety). Part 2.20.

T

T-rail
A guide rail, named for its cross-section.
Tandem operation
Configuration where escalators are stacked end-to-end (e.g., lobby to mezzanine to second floor) so riders step off one straight onto the next. Where riders would pile up, the units must be interlocked so the one feeding the landing stops if the one carrying riders away stops. They must also be interlocked to run in the same direction (6.1.6.6 for escalators, 6.2.6.6 for moving walks).
TDLR (Texas Department of Licensing and Regulation)
Texas Department of Licensing and Regulation, the state-level regulatory authority for elevators and escalators in Texas.
Technical Safety BC (TSBC)
The provincial safety authority regulating elevating devices in British Columbia: permits, licensing, inspections and the adopted code edition. See BC's code adoption timeline .
Tension carriage
The sprung assembly at the bottom that keeps the step chains tight as they wear. Its movement is monitored, which is why mechanics call the sensor the carriage switch.
Terminal landing
The top or bottom landing of the run, the highest and lowest floors served with a hoistway entrance. The terminal stopping devices are named after them.
Terminal stopping device
Any device that stops the car at the top or bottom of its travel. The code layers a normal device, a final device, and (on faster units) an emergency device. Part 2.25.
Toe guard (apron)
The smooth steel plate hanging below the car sill so that if the car stops high, there's no shelf for someone stepping out to fall onto.
Top-of-car operating device
The control station on the car top used to run the elevator on inspection. Inspection speed can be up to 0.75 m/s (150 ft/min), 2.26.1.4.1(d). The 0.13 m/s (25 ft/min) limit, and the rule that it's needed only where there's a car top, are sidewalk-elevator rules (5.5.1.25.3, 5.5.2.17.2).
Traction elevator
An elevator driven by friction between the hoist ropes and a motor-driven sheave, rather than a hydraulic piston. It is the standard design for mid- and high-rise buildings.
Traction machine
A driving machine that moves the car by friction between the suspension ropes and a drive sheave. The ropes aren't wound up; they're gripped and pulled. The common type on roped elevators; geared and gearless are the two families. Part 2.24.1.
Traveling cable
The flexible loop of power and signal wiring that hangs from the car down into the hoistway, feeding everything that moves with the car. It's the one cable that has to survive constant flexing for decades.
Tread
The horizontal top surface of an escalator step where passengers' feet rest. Must be horizontal, slotted to mesh with the combplate teeth, and afford a secure foothold.
Treadway
Moving walk equivalent of the escalator's step band, the running surface passengers stand on. Either pallet-type (6.2.3.5) or belt-type (6.2.3.6).
Truss
The structural steel frame that supports an escalator's entire mechanism between its top and bottom landings. It carries the running gear in operation, and if something fails, the track system has to keep the running gear inside the truss (6.1.3.7). Designed to the applicable structural steel standard (AISC 360 / CSA S16) per 6.1.3.10.1.
TSASK (Technical Safety Authority of Saskatchewan)
Saskatchewan's Technical Safety Authority. Inspects and regulates elevating devices in the province under the Passenger and Freight Elevator Act.
TSSA (Technical Standards and Safety Authority)
Ontario's Technical Standards and Safety Authority. The regulatory authority for elevators and escalators in Ontario (also covers fuel, boilers, amusement devices, ski lifts).
Type test
A test done once on a component design in a lab, rather than on every unit in the field: how a device gets certified for use in the first place.

U

UCM (Unintended car movement)
The car moving away from a landing with the doors open, unbidden. This is the classic gap-entrapment hazard. UCM protection detects it and stops the car, covering failures in the machine, brake, or coupling. Part 2.19.2.
UL 723 (UL 723)
UL's surface burning characteristics test. Accepted alongside ASTM E84, NFPA 255, and CAN/ULC-S102.2 for nonmetallic step/pallet flame-spread certification.
UL (Underwriters Laboratories)
U.S. product safety testing and certification organization. UL 723 is a flame-spread test; ANSI/UL 94 is the plastics flammability standard; both cited in 6.1.3.5.1.
ULC (Underwriters Laboratories of Canada)
The Canadian member of the UL family. Publishes CAN/ULC-S102.2 (surface flammability test) cited as an alternative flame-spread standard in 6.1.3.5.1.
Unintended car movement (UCM)
The car moving away from a landing with the doors open when nothing asked it to: a component or system failure, not a control decision. B44 requires protection that detects it and stops the car (2.19.2).
Unlocking zone
The short zone just above and below a landing where a hoistway door may legitimately be unlocked or opened: the car is close enough that opening is safe, and emergency access keys are designed around it. Outside this zone the door stays locked. Part 2.12.1.

V

VFD (Variable Frequency Drive)
A motor controller that varies the frequency of AC power to control motor speed. Adding VFD control to an existing escalator is an alteration (8.7.6.1.17) and requires conformance to 6.1.6.3.2, 6.1.6.10.3 and 6.1.6.10.4.
VT (Vertical Transportation)
Umbrella industry term covering elevators, escalators, moving walks, dumbwaiters, and platform lifts. Used in credentials, trade publications and some association names.
VVVF (Variable Voltage Variable Frequency)
A motor drive technology that varies both voltage and frequency to give smooth, precise control over acceleration, speed, and deceleration.

W

Welding
Joining metal parts with heat. When welding on parts on which the escalator/moving walk depends (truss, girder, tracks, driving machine), the work must conform to Section 8.8 and 8.7.1.5 (PE-verified design).
Wellway
The building opening (such as the slot in a floor) that an escalator or moving walk passes through between levels. Floor-opening protection requirements come from the applicable building code (6.1.1 / 6.2.3.8.5). Mechanics say well or shaft more or less interchangeably.
Winding-drum machine
A driving machine that raises and lowers the car by winding its ropes onto and off a grooved drum instead of relying on friction. An older technology (mostly freight, residential, and very old installations) carrying its own safeguards such as a slack-rope device. Part 2.24.1.
Worm-geared machine
A driving machine that turns the sheave or drum through worm gearing, the traditional geared traction arrangement.

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