Every industry has its own special vocabulary that outsiders don't understand. But in the lighting field, the technical lingo is sometimes confusing if not incomprehensible even to lighting industry insiders.

In a never ending battle to promote the advantages and technical superiority of their products, manufacturers are increasingly turning their efforts to enhancing ad copy and pouring on the technical jargon in specification sheets.

The idea is to impress specifiers with the image of quality and high technology. Some of this language is true and impressive, and some is just over-hyped copy.

There are also many time-honored catch phrases that are put in every lighting catalog and are never questioned but are nonetheless rarely understood by the very people who are specifying these fixtures.

This article offers a brief glossary of terms with an explanation in plain English as to what they mean and specifically how these attributes should affect fixture specification.

Commercial Lighting Specification Description Terminology

CRT Cathode Ray Tube, what is now called a computer monitor (see VDT).

Low Brightness This usually refers to a reflective surface that doesn't produce an intense glare (or brightness) when looking directly at it.

Photometric Optimization When fixture manufacturers engineer lamp positions, reflectors and/or louver profiles ensure that the maximum amount of light leaving the lamp(s) will end up in the task area, as opposed to being trapped inside the fixture or bouncing uselessly around the room.

Rainbowing An effect that happens with certain types of fluorescent lamps (especially high-color-rendering triphosphor lamps) are used with certain types of lower-end anodized aluminum reflectors and louvers. It causes a noticeable and unacceptable rainbow reflection on the anodized surfaces of the fixtures.

Troffer As the name implies, troffers are trough-shaped recessed ceiling fixtures (the term is derived from the terms "trough" and "coffer." They usually contain fluorescent lamps and have an open surface flush with the ceiling. A parabolic troffer refers to a recessed fixture that has a louver with a parabolic cross section. The parabolic shape redirects light rays from the light source into parallel rays that shine in a controlled fashion into the room.

VCP Visual Comfort Probability. This is a fixture rating system that determines how many people would, when viewing this fixture, find it to have low glare and be comfortable to work near. The higher the number or percentage, the better.

VDT Video Display Terminal, what is now called a computer monitor (see CRT).

Commercial Lighting Specification Materials Glossary Of Terms.

OGa CRS 20-Gauge Cold Rolled Steel. This is the most common type of steel used in the lighting industry. Cold rolling indicates that the steel is not heat-treated or hardened, which allows for easy forming, piercing, stamping or shearing when manufacturing a lighting fixture. Twenty-gauge CRS is in the general range of 0.036 in. in thickness.

l6Ga. Galvanized Steel A steel commonly used in internal or unseen functional parts of a fixture. This metal is used because it doesn't require finishing or painting. Steel is galvanized by applying a layer of zinc to the raw metal sheets. This process helps preserve the material and prevent it from rusting. Sixteen-gauge equals about 0.060 in. thickness.

Clear Specular Alzak Reflector Alzak is a registered trademark, originally of Alcoa. This is a proprietary anodizing process that allows maximum light reflection from the reflective surface with low brightness and glare.

Code Gauge This is a catch-all term used by many people to refer to the gauge of metal used in a fixture -- acceptable to the certain prevailing national electrical or local code requirements for fixture construction.

Pre-Anodized Aluminum Anodizing is one of the most common finishing processes done to aluminum in the lighting industry. Anodizing is a controlled oxidation process that occurs when aluminum is exposed to an electrically charged chemical bath. The end result is a hardening of the surface to resist abrasion and corrosion with an added protective transparent layer to preserve the decorative natural aluminum finish. Anodizing can also produce colored or dyed finishes that are locked into the aluminum surface. Pre-anodizing is usually performed on the raw coil of aluminum before it is fabricated into a louver or reflector.

Semi-Specular This refers to the image one would see in a reflective surface. A true specular reflector would act similar to a mirror where one could clearly see the reflective image. A semi-specular image would produce a more diffuse, less clear and a less glaring image, which is a desirable type of reflector used in a lighting fixture.

Fabrication Processing Glossary Of Terms. 

Die-Formed Manufacturers use die-forming to ensure highly accurate mass-produced parts at low cost. Die-forming uses large, high-tonnage presses with precision-formed and hard-stamping dies to pierce and bend the metal material. These large automated presses rapidly and economically produce complicated sheet metal parts with a high quality of fit.

Hydro-Formed This forming process allows the precision production of non-round asymmetric difficult-to-form reflector shapes. It allows designers to optimize reflector performance for non-centered lamps or fixtures that produce specific directional photometric properties.

Die-Cast A process that usually involves the high-pressure injection of zinc or aluminum into a hardened mold to produce a highly accurate part with high strength and detail.

Fixture Parts Terminology

Louver A series of baffles arranged in a geometric pattern used both to shield a light source from an unwanted viewing angle and to redirect the remaining light to a more usable location.

Luminaire A complete lighting fixture.

Protective Dust Guard After fixture installation, this dust guard is a plastic film placed on the decorative faces of the reflectors and louvers (unfortunately, many end-users forget to take it off upon installation, impairing reflector performance).

Wireway Cover A cover of a fluorescent fixture that usually encloses access to the splice compartment and the ballast location.

Light Fixture Finishing Glossary Of Terms.

Baked White Enamel A common paint finish that is applied in a "wet" form and applied with a gun or automated sprayer. The paint is usually attracted to the metal part electrostatically to prevent excessive paint overspray. The paint is finally baked on for maximum adhesion. The final paint thickness is usually 0.7 to 1.1 mm when dry.

Five-Stage Iron Phosphate Pretreatment The standard process required to best prepare sheet steel for painting. The initial phase uses a high alkaline base bath to remove oil deposits and take out stains. The next stage is a water bath, then an iron phosphate acid bath to etch the metal to prepare it to accept and hold the paint well, then another water bath. The last stage is a sealer that does the final cleaning of the metal and makes the water droplets completely run off the surface to eliminate any moisture from remaining and combining with the final painted surface.

Powder-Coated Finish This process is used when a tougher, more durable paint coating is required. The final paint thickness is up to 2.25 to 2.5 mm when dry. The paint is a dry resin powder that is applied with a special spray applicator. The powder is electrostatically attracted to the charged metal surface being painted. This process has many similarities to the baked white enamel (see above), although it is a more expensive process. It is used on parts that see more handling or wear-and-tear and on parts that need better weather resistance.

Electrical & Safety Commercial Lighting Glossary Of Terms.

#12AWG 90C Conductor This conductor (or wire) is a No. 12 size American Wire Gauge electrical wire. It is equal to 0.095 in. diameter with an insulation that can withstand up to a 90C (194F) temperature.

AWM/THHN Wire Appliance Wiring Material (AWM) is common internal fixture wiring. THHN wire is rated at 90C and can carry up to 600 volts; it is a heavier nylon jacketed wire (for use in dry locations) that can be used in connections with building wiring.

Damp Location/Wet Location In general, damp location fixtures can be used in areas where a certain level of humidity is present but the fixture itself does not come into contact with water (such as an exterior building soffit). Wet location fixtures allow some contact of water with the exterior of the fixture. Vaportight fixtures allow the fixtures to operate in a very high humidity application like a shower stall.

Power Whips/Modular Wiring Power whips are simply armored wire cables that are factory-installed so an electrician can connect several nearby fixtures to one common junction box instead of bringing electrical service to every individual fixture in a large ceiling area. Modular wiring is a specially designed cabling system that allows electricians to easily connect an entire series of lighting fixtures using a modular connector plug that easily fits into a mating receptacle specially mounted in each fixture.

Tandem Wiring/Master Slave Wiring Tandem wiring is when two (or more) fixtures are attached together and wired into only one fixture but then internally wired to the other(s). Master Slave wiring is when the electrical power is brought into one fixture (master) and the ballast of that one fixture controls the lamps inside other nearby similar fixtures (slaves). A long run of strip lighting can benefit from such a configuration. This is especially true when the electrician would only have to replace one multilamp ballast instead of three when the fixture ballast requires maintenance.

UL 1570 Indicates Underwriters Laboratories Inc. requirements for fluorescent fixtures

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UL 935 Indicates Underwriters Laboratories Inc. requirements for fluorescent ballasts.

Commercial Lighting Lamp & Socket Glossary Of Terms.

G24q2 This is a designation for a socket for a compact fluorescent lamp. Since there are very many compact fluorescent lamp types and an equal number of socket types, a numbering system was developed to identify the different variations. "G" is the European designation for sockets that accept two or more lamp pins. "24" is the spacing in millimeters between the lamp pins in the base of the lamp. The "q" indicates that this socket accepts 4 (or quad) pins and the "2" indicates that this variation on this socket only accepts an 18W lamp (to prevent users from mislamping the socket, the lamp manufacturers put tabs on the bottom of the lamp base to ensure that only the correct wattage lamps are used in that fixture).

T8 or T-8 This is the American lamp designation for a tubular (1) lamp. Linear fluorescent lamps commonly use this lamp designation. The "8" refers to the tube diameter as a number of 1/8 inches (8 "eighths") or one inch in diameter. The European description is T26 (26 mm in diameter). Similarly, a T12 is tubular and 12/8 in. or 1.5 in. in diameter. The European description is T38 (38 mm in diameter).

CFL Compact Fluorescent Lamp. These lamps still go by many names and specifications: PL (Philips), Biax (GE), Dulux (Osram Sylvania) and other trade names. A TC (tubular compact) followed by letter(s) is the European system of CFL lamp classification.

Commercial Lighting Ballast Glossary Of Terms.

120V 60Hz AC 120-Volt Alternating Current is the standard voltage used in many of the residential and light commercial buildings in the United States; most lighting fixtures and ballasts are designed to run on at this voltage level. Hertz (Hz), or cycles per second, is a unit of frequency of electric current. Sixty Hertz is the common U.S. rating.

277V 60Hz AC 277-Volt Alternating Current is a common voltage standard used in many commercial fixture applications in the United States. The higher voltage makes it easier to wire many fixtures together on fewer circuits, making installations easier and simpler. Specially designed ballasts are required for operation at this voltage.

Ballast Used in gaseous discharge systems (fluorescent and high-intensity discharge), the ballast starts the lamps and then regulates the flow of current during normal operation.

CBM Certified Certified Ballast Manufacturers Association certification identifies ballasts that are produced to conform to American National Standard Institute (ANSI) standards.

Class P-Rated Class P is a standard created by UL that indicates it has an internal thermal protection device to protect against overheating, excessive voltage supply, internal ballast short circuiting, inadequate lamp maintenance and improper fixture application. In the event the ballast overheats, the thermal protection device will shut off the ballast until it cools; once it cools sufficiently, the ballast is reconnected to the power supply and it reignites the lamps. If this process continually repeats itself due to a temperature problem, it is called "cycling."

Electronic Ballast These ballasts differ from magnetic ballasts in that they generally consist of a printed circuit board with semi-conductor technology that electronically regulates the voltage to start and run the fluorescent lamps instead of physically changing the voltage as the magnetic ballast does. Due to the increased level of control, this ballast can operate at a higher current frequency range and send a more precise and efficient flow of voltage through the lamp. This creates a brighter, more efficient lamp operation. Some electronic ballasts include all electronic components, while some include a mix of electronic and magnetic components.

Federal Ballast Energy Law The Federal Ballast Energy Law (Public Law 100-357) was enacted in 1988 as part of the National Appliance Energy Conservation Amendments (NAECA '88). The law set minimum ballast efficacy standards for four major fluorescent lamp types. As of 1991, ballasts submitted for testing by the U.S. Department of Energy and complying with NAECA '88 provisions carry an E symbol on their labels. Ballasts exempt from NAECA included dimming ballasts and ballasts used in areas where ambient temperatures reached 0F or lower.

Magnetic Ballast Also called an electromagnetic ballast. These are the most basic and oldest type of fluorescent ballasts. The basic construction consists of a core of stacked steel plates wrapped with a coil of copper or aluminum wire (a basic electron magnet). This is then potted in an insulating material such as asphalt to conduct the heat of the ballast outward. The entire assembly is then put into a metal housing to prevent breakdown and shock hazard. Usually a separate starter of various different designs is incorporated into this housing to provide the additional voltage needed when initially starting a fluorescent lamp. Some HID ballasts require an external ignitor.

THD Total Harmonic Distortion. This term describes distortion that sometimes occurs when the need for current is not in equilibrium with the supply of this current. On one side, a fluorescent lamp can draw short pulses of current instead of asking for a constant supply of current. On the other side, when turning on a ballast, a large in-rush of electric current can occur. The ballast between the lamp and the supply current is trying to balance the needs of the lamp with the amount of current it is receiving at that moment. Low THD ballasts can also be compared to surge protectors because they act to protect themselves and other electronic components by preventing power surges. This is not a major problem for most ballasts and in most applications. In larger buildings with many fluorescent fixtures, however, THD can present a significant problem and if not precalculated and controlled can possibly overload the normal flow of current in the system. The lower the THD rating of the ballast, therefore, the better (below 20 percent is preferred).

LABEL TERMINOLOGY

CSA Canadian Standards Association is the testing authority for ballasts and electrical products used in Canada, similar to UL.

CUL UL certification of testing to Canadian UL standards.

IBEW Union Made International Brotherhood of Electrical Workers. This label represents that the fixture it is attached to is union-made. It is useful on larger construction jobs where the use of union-made products is encouraged. Job sites in certain larger cities strongly encourage the use of fixtures made by specific local unions.

IC Fixture Insulated Ceiling Fixtures are allowed to be placed against and surrounded by building insulating material commonly found in areas such as residential attics.

NOM The Mexican standards testing agency similar to UL.

UL Underwriters Laboratories, an independent non-profit organization that tests products for public safety. Through use of study experimentation and testing, their mission is to prevent the loss of life and property from the hazards of fire, casualty and crime.

COMMERCIAL LIGHT LISTINGS GLOSSARY OF TERMS. 

NYC Code A set of fixture requirements regulated by the government of New York City. It assigns a Calendar Number to every manufacturer's fixture submitted; this number is required before installation. The highlight of this code is that it requires fixture manufacturers to build their fixtures of 20-gauge steel material or better and attach these parts with approved mechanical fasteners to ensure better fixture strength and integrity.

Chicago Plenum A requirement for all lighting fixtures that will be installed in the City of Chicago. The main feature is that any fixture installed in a ceiling air plenum (the space between the finished or suspended ceiling and the main structure above) needs to have special gasketing to completely enclose the junction box, splice compartment or fixture wireway to avoid electrical sparking, fire or other hazardous situations that might encroach into the ceiling plenum or room below.

Now check out two "sample specifications" -- the italicized words correspond to the definitions above:

XYC Lighting Incorporated
Parabolic Troffer Series
P2448 2x4
4-in. Deep Louver/ 2,3,4 lamps

Description A new family of high performance 2x4 recessed deep-cell parabolic troffers designed to maximize the output of T12/T8 lamp and ballast combinations. This low-brightness troffer provides especially good lamp cut-off and is particularly applicable to areas with high VDT (CRT) usage. Computer photometric optimization has led to a more efficient parabolic luminaire with a high VCP, good glare control and optical performance. These fixtures come with optional heat removal dampers and air pattern control blades that allow enhanced airflow control. T-hinges are die formed for maximum strength. Latches are spring loaded, concealed in reveal.

Construction Each fixture housing is die-formed from heavy code gauge or optional 20-gauge CRS. Ends and housing parts are securely riveted into place. Reflecting surfaces of body and reflector/wireway covers match precise parabolic contours of louvers. Louvers are constructed of semi-specular low-iridescence pre-anodized aluminum. All parabolic louvers are accurately held into place with interlocking construction and louvers feature mitered corners. Fixtures come packaged with a protective film dust guard.

Finish Five-stage iron-phosphate pretreatment allows excellent paint adhesion and rust resistance. Finish paint coat is a high reflectance baked white enamel. Provides a reflectivity of 86% or higher.

Wiring And Electrical Fixture conforms to UL 1570 and is suitable for damp locations. AWM or THHN wire is used throughout and is rated for required temperatures. All electrical components are UL-approved. Standard wiring, tandem wiring and master-slave wiring are available. Factory-installed fixture power whips and modular wiring systems are available as specified.

Ballasts All supplied ballasts are Class P rated HPF (high power factor) non-PCB CBM-certified ballasts. They comply with the Federal Ballast Law (Public law 100-357, 1998). Each is a thermally protected and resetting type. Energy-saving and electronic ballasts are sound rated A and have a THD of less then 20%. Ballasts are also CSA-certified and pass UL 935. Magnetic ballasts are also available. (Specify voltage l20V 60Hz AC or 277V 60Hz AC.)

Labels Luminaires bear appropriate UL and CUL recessed fixture labels. Optional CSA certification and NOM-labeled fixtures are available. IBEW-made and labeled.

Listings NYC Code - For products that meet NYC Code requirements. Chicago Plenum - For products that meet Chicago Plenum requirements.

XYZ LIGHTING CO INC
8-in. Horizontal Quad Open Reflector Downlight
6QCF 18/26W single- or double-quad lamp

Description A series of low brightness downlights for use with 18W and 26W quad CFL. Provides wide beam distribution and highly efficient delivery of uniform illumination with excellent color rendition. The precisely formed non-imaging optical reflector ensures equal cutoff to lamp and lamp image and offers unparalleled glare-free performance. This series offers visual comfort suitable for most general lighting.

Reflector Precision hydro-formed 0.050 aluminum with clear specular Alzak low iridescent finish for eliminating "rainbowing" while maintaining full light output. Vented to cool lamp. Interchangeable with screw attachment.

Trim Self-flanged with matte white powder-coated finish. Covers ceiling opening without light leaks.

Mounting Frame Precision die-stamped plaster frame of 16-Gauge galvanized steel. Has universal mounting brackets with 3-1/2 in of vertical adjustments. Ballasts and galvanized metal junction box are accessible from below. Friction springs and snap on precision die cast socket cup ensure correct optical alignment without adjustments.

Sockets Two G24q2 horizontally mounted 4 pin plug-in type sockets ensure correct optical placement. Lamps are tilted for maximum heat dissipation and efficiency.

Electrical Junction box comes with 1/2-in.- and 3/4-in.-diameter pryouts listed for 8 #12 AWG 90C conductors.

Ballasts Full light output electronic 120V or 277V HPF thermally protected Class P internally fused; quiet flicker free operation. Soft non-pulsating starting down to 5F. Power Factor 99%; THD 10%.

Labels UL-listed and CSA Certified. Non-Type IC fixture. Feed through junction box. Approved for use in dry or damp locations and approved for branch circuit wiring. IBEW-made.

Listings NYC Code - For products that meet NYC Code requirements. Chicago Plenum - For products that meet Chicago Plenum requirements.

RLLD Commercial Lighting carries a wide variety of industrial & commercial lighting fixtures. If you can not find what you are looking for call us toll free at 1-866-654-3961 and we will find it for you. Our home office is located in Houston, Texas with warehouses located throughout the United States that enable us to service all 50 states including  San Juan, PR (SJU), Isla De Vieques, PR (VQS), Fajardo, PR (X95), Erie, PA (ERI), Killeen, TX (ILE), Sheridan, WY (SHR), Casper, WY (CPR), Parkersburg, WV (PKB), and Escanaba, MI (ESC). We also service clients internationally, with lighting manufacturer representatives working out of Canada, Mexico, Central America, and South America. ALBQ, NYC, LA, MPLS.