DEFINITIONS
I thru Z
Incandescent - Incandescent Lamp
A lamp that produces light by current passing through a tungsten or similar filament (traditional light bulb.)
Insulator Bushing
A ceramic bushing used as an entrance for conductors in a metallic pendant luminaire.
Lamp
The actual luminous bulb in a luminaire.
Lamp Holder
A component that holds a socket and positions it into proper place.
Latch
A device for securing luminaire components that can be easily opened, generally not including lever latches or ring latches used to hold reflectors onto pendant luminaires.
Lower Housing
The lower portion of a luminaire, typically cobrahead design, that holds the refractor and encloses electrical components.
Lugs
Conductor connections typically found on binding posts and sockets.
Mast
A metal or concrete pole to which a bracket arm is attached, also referred to as a column.
Mounting Threads
Large threaded connections between components on some vintage pendant luminaires, generally secured with set screws.
Multiple Circuit
A circuit where a number of luminaires are connected in parallel, generally operating at 110 volts.
Nadir
A term in optical engineering that refers to the area directly below a street light
Neck
A general term that applies to a portion of a luminaire fixture that slips into another portion of the luminaire.
NEMA - National Electric Manufacturer's Association
A manufacturer's association that establishes design standards for luminaires.
NEMA Head
An all metal (usually aluminum) luminaire head that is designed to be interchangeable with various bracket arms and uses a standard interchangeable "latch-on" system for mounting reflectors and refractors.
Open Circuit
A circuit that is inoperative due to an open switch or malfunction.
Open Loop
A high tension series circuit where the conductor leads travel in separate directions and eventually form a loop.
Pencil
Nickname for a carbon arc electrode.
Photo Control - Photoelectric Control
A light sensitive device, typically mounted on a luminaire, that turns the luminaire on at night.
Pole
A vertical support for wiring and luminaires, different from a mast or column as a pole is made of wood.
Quarter Moon
An admiral's hat reflector that also has cutoff deflectors on each end causing it to resemble a quarter moon, also referred to as a "crescent moon."
Radial Wave
An open reflector that has rippled edges in order to better reflect light horizontally.
Rain Shield
A metal shoulder designed to keep water from entering a luminaire.
Receptacle
The receiving contacts for a removable series circuit socket.
Reflector
A polished piece of metal, generally elliptical or oval in shape, that fits above a lamp to reflect light into a refractor. In some open models the light reflected directly from the luminaire.
Refractor
Glass that includes small prisms or other surface features that redirects light toward specific directions.
Refractor Holder
The portion of a luminaire such as a clamshell or cobrahead that specifically holds the refractor.
Regulator
A device that controls voltage to a series street light circuit, adjusting the voltage according to the number of lamps actually working.
Ring Latch
A lever type latch that holds reflectors tight to luminaire bodies.
Scroll
A flat strip of metal, often ornamentally curved, placed at an angle between a bracket arm and mast or pole that helps reduce vibration.
Scroll Arm
A bracket arm that includes a scroll for ornamental or vibration dampening purposes.
Shoulder
A portion of a ceramic luminaire body that extends outward around the body to deflect rain and prevent it from entering the luminaire.
Series Circuit
A number of luminaires operating where current passes through each lamp in series. Series circuits operate from a high voltage source, with the voltage divided between each lamp in the circuit and controlled by a regulator.
Shepherd's Crook
A bracket arm that has a sweeping upward, then downward bend at the end resembling a shepherd's crook, more correctly called a "bishop's crook."
Skirt
The portion of a canopy or crown that fits over and surrounds the top of a ceramic luminaire, often containing set screws.
Slip Fitter
A connecting device for a luminaire that slips over the end of a bracket arm and is secured by a clamp and/or set screws.
Socket
The actual component into which the lamp screws into.
Supporting Collar
A collar specific to horizontally attaching a ceramic luminaire to a slip fitter.
Supporting Pipe
A small section of pipe, often referred to as a nipple, that connects components together, such as the threaded fitter atop a pendant luminaire to a bracket arm end fitting.
Teardrop
A common term for an elogated refractor, similar to a gumball, that is longer than it is wide.
Terminals
Points where conductors are secured to binding posts or other electrical components.
Threaded Cap
The threaded portion on the top of a pendant luminaire that attaches to a bent bracket arm or supporting pipe.
Upper Housing
The main upper portion of a fluorescent or cobrahead luminaire.
Upswept - Upswept Arm
The shape of a bracket arm that sweeps upward from a mast to provide additional elevation for a luminaire.
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