HID LAMPS COMMONLY USED IN OUTDOOR APPLICATIONS:  

CLASS I, GASES

(NEC ARTICLE 500-5, 501-9) Areas where inflammable gases or vapors may be present in sufficient quantities to produce explosive or flammable mixture.

CLASS II, DUST

(NEC ARTICLE 500-6, 502-11) Areas where combustible dusts are present.

CLASS III, FIBERS

(NEC ARTICLE 500-7, 503-9) Areas where ignitable fibers or flyings are present in sufficient quantities to produce ignitable mixtures.

DIVISION 1, ALWAYS PRESENT

(NEC ARTICLE 500-Sa, 500-6a, 500-7a, 501-9a, 502-ha)  Areas where the hazardous condition is normally present either continuously or periodically.

DIVISION 2, NOT NORMALLY PRESENT

(NEC ARTICLE 500-Sb, 500-6b 500-7b, 501-9b, 502-lib)  Areas where the hazardous condition is present due to accidental rupture, breakage or unusual faulty operation of a closed container or system.

*BASED ON 40 DEGREES C (104 degrees F) AMBIENT

TYPE INTENDED USE AND DESCRIPTION

1.      Enclosures, to be used indoors where unusual service conditions do not exist, that are to prevent accidental contact of personnel.

2.      Enclosures for indoor use that protect equipment from falling dirt and falling non corrosive liquids.

3.      Enclosures for outdoor use that protect equipment from  windblown water, dust, and are ice resistant.

3R.   Enclosures for outdoor use that protect equipment from rain and are ice resistant.

3S.     Enclosures for outdoor use that protect equipment from windblown water, dust, and are ice proof.

4.     Enclosures for use that protect equipment from hose directed water and are dust tight. 

4X. Enclosures for use that protect equipment from hose directed water, and are dust tight and corrosion resistant.

6.   Enclosures for indoor or outdoor use that might be submerged occasionally that protects equipment from a static head of six (6) feet of water for thirty (30) minutes are ice resistant.

7.   Enclosure for indoor use in area classified as CLASS I, and Groups A, B, C or D in the “National Electrical Code”.

8.   Same as “TYPE 7” except equipment is immersed in oil.

9.   Enclosures for indoor use in areas classified as CLASS II and Groups E, F or G in the “National Electrical Code”.

10.   Enclosures that meet U.S. Bureau of Mines Requirements for atmospheres containing methane and air, with or without coal present.

11.   Enclosures for indoor use which contain equipment immersed in oil that protects equipment from dripping, seepage and condensation of corrosive liquids.

12.   Enclosures for indoor use that protect equipment from dust, dirt, and light splashing of non corrosive liquids.

13.   Enclosures for indoor use that protect pilot devices from dust and spraying water, oil or coolant.

TERMS USED IN THE LIGHTING INDUSTRY:

A-lamp:   the common incandescent light bulb used in most homes in North America. An A-lamp can have a clear, white-coated, or etched-frost glass envelope.

Acrylic:    a plastic used to shield the lamps in luminaires or to distribute the luminous intensity, or both. Acrylic resists yellowing from ultraviolet radiation, but becomes brittle.

Adaptation:  the process by which the human visual system adjusts to light levels. Complete adaptation takes considerable time, especially when changing from a light to a dark environment.

Aiming:    the process of directing the light distribution from a luminaire toward the object or area to be light-ed. Proper aiming is critical to prevent direct glare.

Annual operating cost:    the cost per year of and maintenance of a lighting system, replacement parts and associated labor. electricity including Anodizing: a process for chemically treating aluminum to provide a durable, protective finish.

ANSI:  American National Standards Institute. ANSI coordinates and approves the processes for developing voluntary national standards, including those related to the lighting industry.

Arc:    an electrical discharge through an ionized gaseous atmosphere. Fluorescent and HID lamps are examples of light sources that use an arc to produce light.

Arc tube:    an envelope, usually quartz or ceramic, that contains the arc of a discharge light source.

Aria of calculation:    a lighted surface over which numerical values (illuminance or luminance) are calculated. Values may be given for particular points within the area of calculation, or may be an average of all points within the area.

Area lighting:    lighting provided to illuminate open areas uniformly.

ASHRAE:  American Society of Heating, Refrigerating, and Air-Conditioning Engineers.  ASHRAE, in conjunction with IESNA, has developed standards for energy efficiency in new and existing buildings. Lighting, including exterior lighting, is an important part of the ASHRAE/IES Standard 90.1, Energy Efficient Design of New Buildings Except Low-Rise Residential Buildings.

Astronomic timer:  a control that changes its settings based upon seasonal daylight variations.

Average rated lamp life:   the time in hours for a given percent (often 50 percent) of a large group of lamps to fail under standardized operating conditions. For fluorescent lamps, the conditions include cycles of operation at nominal line voltage at 3 hours per start. For HID lamps, the lamps are operated at 10 hours per start. Any individual lamp, or group of lamps, may vary from the published average rated life.

Average to minimum (avg:min):    the ratio of average numerical value (illuminance or luminance) to the minimum value found within a lighted area. It is one of the measures used to indicate lighting uniformity.

Ballast:    a device that provides the necessary voltage, current, and wave form for starting and operating fluorescent or HID lamps.

Beam spread:   the width, expressed in degrees, of a light beam from a reflector lamp. The edge of the beam is typically defined as the point at which the luminous intensity is 50 percent as great as at the center of the beam. See also center beam candlepower (CBCP).

Bollard:  a low past-shaped luminaire, typically 3 to 4 ft. in height, used to light pathways, walkways, and perimeters.

Brightness:     the subjective impression of the amount of light reaching the eye. Brightness correlates approximately with luminance, a photometric measurement.

Bulb:     the outer glass envelope of a light source.

Candlepower:     see luminous intensity.

Center beam candlepower (CBCP):  the luminous intensity (in candelas) of a reflector lamp, measured at the center of the beam.

Color rendering index (CR1):  a measure of the color shift objects undergo when illuminated by a light source relative to incandescent or daylight of the same COT

Color temperature: see correlated color temperature.

Compact fluorescent lamp:  a fluorescent lamp with a tube diameter of 5/8 inch or less (T5) having one or more bends in the tube(s).

Constant wattage (CW) ballast:    a magnetic ballast used for mercury vapor and high pressure sodium lamps, providing the best lamp-wattage regulation available. The CW ballast provides constant wattage for changes in line voltage + or - 10 percent.

Constant wattage autotransformer (CWA) ballast:   a magnetic ballast for HID lamps that uses a transformer in conjunction with a reactor (a coil wound on an iron core), as well as a capacitor in series with the lamp, to provide stability when voltage fluctuates 10 percent.

Contrast:   the luminance of an object related to its immediate background. See also luminance contrast.

Control:    a device or system that turns lamps on and off, or dims them. Controls include switches, dimmers, timing devices, motion detectors, photosensors, and central control systems.

Correlated color temperature (CCT):      an indication of the color appearance of a light source, measured in Kelvin (K). The CGT rating of a lamp is a general measure of its warmth or coolness. Lamps with a CCI rating below 3500 K are generally considered warm sources, while lamps above 3500 K are considered cool sources.

Current:    a rate of flow of electricity, measured in amperes (A).

Cutoff luminaire:  an outdoor luminaire having light distribution characteristics designed to reduce luminous intensity at angles above 650 from vertical. Cut-off luminaires generally provide well-defined patterns of light.

Diffuser:    a device that redirects or scatters light from a source.

Dimmer:  a device used to vary the luminous intensity of light from a lamp. Dimmers may be electronic or magnetic, and can dim smoothly or in discrete steps.

Direct glare:     excessive brightness from a source of light in the line of sight. Luminaires with poor optical control can be sources of direct glare.

Distribution:      see light distribution.

Efficacy (of a light source):   the total light output of a light source divided by the total input power. Efficacy is expressed in lumens per watt.

Efficiency (of a luminaire):    the ratio of luminous flux (lumens) of a luminaire to the luminous flux of the lamp(s) alone. Luminous efficiency is a dimensionless measure, expressing the percentage of initial lamp lumens that exit the luminaire.

Electrode:    the structure that serves as electric terminals at each end of electric discharge lamps. The electrodes of fluorescent lamps are made of coiled tungsten, covered with an emissive paste. Electrodes in HID lamps are heavier post-like structures capable of carrying high current.

Electronic ballast:    a ballast that uses electronic circuitry, rather than magnetic components, to provide the voltage, current, and waveform to start and operate lamps. Electronic ballasts typically operate lamps at very high frequencies.

Energy:    the product of power (watts) and time (hours). Energy used for lighting can be saved by reducing the power required or the time lighting is used, or both.

EPACT:   the United States Energy Policy Act of 1992. This legislation mandated efficacy and color requirements that caused the elimination of many incandescent R and PAR lamps and full-wattage, low-CRI fluorescent lamps, among other energy-saving measures.

Facade:  exterior vertical surface of a building.

Filament: a fine wire that is electrically heated to incandescence.

Fitting:   (chiefly British) see luminaire.

Fixture:   see luminaire.

Flood lamp:    a reflector lamp that produces a wide beam of light.

Flood light:     a luminaire that produces a relatively wide beam of light.

Fluorescence:    the ability of some materials, such as phosphors, to convert ultraviolet energy into visible light.

Fluorescent lamp:   a lamp containing mercury under low pressure, relative to high intensity discharge lamps. The mercury is ionized by an electric arc, producing ultraviolet energy which, in turn, causes a phosphor coating inside the lamp to fluoresce.

Foot-candle (fc):    unit of illuminance, equal to one lumen per square foot. One foot-candle equals 10.76 lux (lx).

Galvanizing:  a process by which zinc is deposited on the surface of another metal to improve resistance to corrosion. Steel poles for outdoor lighting are often galvanized for use in corrosive atmospheres.

Glare:    excessive brightness.

Globe:     a spherical transparent or diffusing enclosure intended to protect a lamp or to diffuse or change the color of its light.

Halogen Infrared PAR lamp:    a reflector lamp using a halogen capsule inside a PAR enclosure. The capsule is coated to redirect radiant infrared energy back to the filament, thereby increasing lamp efficacy.

Halogen lamp:    an incandescent lamp that employs a halogen-gas additive to improve lamp life and efficacy.

High intensity discharge lamp (HID):   an electric lamp that produces light directly from an arc discharge under high pressure. Metal halide, high pressure sodium, and mercury vapor are types of HID lamps.

High pressure sodium lamp:     an HID lamp in which radiation from sodium vapor under high pressure produces visible light, characterized by a golden-yellow color

High reactance autotransformer (HX) ballast:       a ballast used with HID lamps, consisting of a transformer in the form of primary and secondary coils, used in conjunction with a reactor (a coil wound around an iron core). A capacitor is added across the line for power-factor correction.

IESNA:     Illuminating Engineering Society of North America. IESNA is a technical society whose member-ship is interested in the art, science, and practice of illumination.

Illuminance:    luminous flux density, measured in lumens per unit area. Two common units used to measure illuminance are foot-candles (lumens per square foot) and lux (lumens per square meter). For conversion purposes, 1 foot-candle (fc) is equal to 10.76 lux (lx).

Incandescent lamp:    a lamp producing visible radiant energy by electrical heating of a filament.

Initial cost:     the cost of buying and installing equipment, exclusive of operating costs such as energy, maintenance, and lamp replacement.

Input power:  the total power used by a lamp and bal-last, if required, measured in watts.

Instant-start circuit:    a circuit used in ballasts for fluorescent lamps. High voltage is applied directly across lamp filaments, causing lamps to start instantaneously. Instant-start circuits start well in cold weather, require low input power, and ignite without lamp flicker

Intensity:     see luminous intensity.

Interval timer:     a lighting control that automatically switches a luminaire off after a selected time interval.

Kelvin (K):    the standard unit of temperature used in the Systeme Internationale d'Unite (SI) system of measurements. The Kelvin scale is used to describe the correlated color temperature of a light source.

kilowatt-hour (kWh):     measure of electrical energy use; the product of power, as measured in kilowatts, and time, as measured in hours. For example, one kilowatt used for one hour equals one kilowatt-hour (kwh).

Lamp:     a manufactured light source. For electric lamps, it includes the bulb, the base, and the internal structure that produces light, either a filament or an arc tube. Lamps are often referred to as light bulbs.

Lamp life:   see average rated lamp life.

Lens:   a glass or plastic element of a luminaire that redirects and controls the distribution of light by refraction.

Light:  radiant energy that is capable of producing a visual sensation. The visible portion of the electromagnetic spectrum extends from about 380 to 770 nanometers. See also wavelength.

Light distribution:     the spread of light that is produced by a lamp or a luminaire; also the overall pattern of light on a surface.

Light output:    luminous flux, measured in lumens. The lumen rating of a lamp is a measure of its total overall light output. See also lumen.

Light pollution:   adverse effects, including glare, light trespass, and sky glow, of unwanted light in the atmosphere, typically produced by the upward components of outdoor lighting systems at night.

Light trespass:  extraneous light on adjacent property, typically produced by stray light from outdoor lighting systems. Light trespass includes glare from direct viewing, as well as unwanted “spill light.”

Lighting design:  the planned application of a lighting system to a space.

Lighting patterns:   lighting plans applicable to common spaces and building types.

Lighting system:     the equipment used to produce and distribute light, including a luminaire and control system.

Low pressure sodium:   a discharge lamp that produces light using a sodium arc in a low pressure atmosphere, characterized by a deep yellow color.

LRC:     Lighting Research Center, a multidisciplinary facility for research and education in lighting at Rensselaer Polytechnic Institute.

Lumen:     the unit of luminous flux. The lumen is the rate of flow of light, and is used to express the overall light output of a lamp.

Lumens per waft (LPW):    see efficacy.

Luminaire:      a complete lighting unit consisting of a lamp or lamps, together with the parts designed to distribute the light, to position and protect the lamps, and to connect the lamps to a power supply.

Luminance:       the photometric quantity most closely associated with the perception of brightness. It is the luminous intensity emitted or reflected in a particular direction per unit area of reflective surface, measured in candelas per square feet or square meters.

Luminance contrast:    a measure of the difference in luminance of an object and its background.

Luminous flux:    the rate of the flow of light, measured in lumens. The overall light output of a lamp.

Luminous intensity:     total luminous flux within a unit solid angle, in units of candelas.

Lux:     the Systeme Internationale d'Unite (SI) unit of illuminance equal to 1 lumen per square meter. One lux equals 0.0929 foot-candles.

Magnetic ballast:     a ballast that uses a magnetic core and coil to provide the voltage, current, and wave form to start the lamp (s) and to maintain operation. See also ballast.

Matte surface:    any surface which has a primarily diffuse reflectance.

Maximum to minimum (max:min):   the ratio of the maximum illuminance or luminance to the minimum illuminance or luminance found within a lighted area. It is a measures used to indicate lighting uniformity.

Mercury vapor lamp:   an HID light source in which radiation from mercury vapor produces visible light, which is characterized by a bluish-white color

Metal halide lamp:   an HID light source in which radiation from a mixture of metallic vapors produces visible light, characterized by a white color.

Motion detector:   also called an occupancy sensor, a device that senses the movement of people, animals, and objects using a passive infrared and/or ultrasonic sensor.  Motion detectors control other devices, such as luminaires and alarm systems that activate when motion is detected. See also passive infrared and ultrasonic.

Mounting height:    the distance from the lamp center within the luminaire to the ground.

NEMA:   National Electrical Manufacturers Association. NEMA comprises companies that manufacture electrical equipment, including lighting.

NLPIP:    National Lighting Product Information Program.  NLPIP is a program of the Lighting Research Center (LRC) at Rensselaer Polytechnic Institute that tests the energy efficiency of lighting technologies and products and produces publications that describe the manufacturer-specific performance characteristics of these technologies.

Occupancy sensor:    see motion detector.

Operating cost:    see annual operating cost.

Parabolic aluminized reflector lamp (PAR lamp):    an incandescent, halogen, or HID lamp with a hard glass bulb, an interior reflecting surface, and a lens to control beam spread.

Passive Infrared (motion detector):   a technology used in motion detectors to sense a change in the distribution of infrared energy (heat). When a passive infrared sensor detects motion across zones, it activates the device being controlled, such as a luminaire or an alarm. See also motion detector

Phosphors:    chemical compounds that coat the inside of fluorescent and some HID lamps. See also fluorescence.

Photosensor:    a device that converts light to electrical current. Photosensors switch lights on or off, based on the amount of incident light.

Polycarbonate:     a strong, high-impact plastic material used in luminaires to shield the lamps or to distribute luminous intensity, or both. Polycarbonate shields or refractors are often used to improve the vandal resistance of luminaires. The material will yellow and lose strength when exposed to ultraviolet radiation (UV) for prolonged periods, less so when it has been UV-stabilized.

Power density:  a measure of electrical power per unit area, measured in watts per square foot or square meter. Many building codes prescribe maximum power density values for various areas of use in an effort to promote the use of energy-efficient products.

Preheat circuit:     a simple electrical circuit used in ballasts for many compact and short linear fluorescent lamps. Preheat circuits are inexpensive and provide a reliable start in cold weather; however, they have low power factors, cannot be dimmed, and produce flashing during lamp ignition.

Quartz halogen lamp:    see halogen lamp.

Rated power:    the nominal lamp wattage.

Rapid-start circuit:   a circuit used in ballasts that preheats the electrodes of fluorescent lamps and then provides for their continuous heating.  Advantages over preheat and instant-start circuits include longer lamp life and dim ability. Disadvantages include increased input power, more fragile electrodes, and unreliable starting below 50 degrees F except with low-temperature versions.

Reactor ballast:  a ballast for HID lamp operation, consisting of a single coil wound on an iron core, wired in series with the lamp, and a capacitor to increase power factor. Reactor ballasts are typically used for mercury vapor lamps, and when line voltage does not vary more than 5 percent.

Rare-earth phosphors: phosphors containing rare earth elements, which are used in fluorescent lamps to achieve higher efficacy and better color rendering than can be achieved with standard phosphors.

Rated life:   see average rated life.

Reflectance:    a measure of how effectively a surface diffusely reflects light. Reflectance is the ratio of lumens reflected from a surface to lumens incident upon it,

Reflected glare:    excessive brightness from reflections in polished or glossy surfaces in the line of sight.

Reflector:     a surface of polished or painted metal, mirrored glass, or meralized plastic shaped to direct light.

Reflector lamps:    a class of lamps that have reflecting material integrated into the lamp. Types include common reflector (R), parabolic aluminized reflector (PAR), and multi-faceted reflector (MR) lamps.

Refractor:    a device that transmits and redirects the luminous flux from a source. Refractors for outdoor luminaires are typically made from acrylic, polycarbonate, or glass, and when well-designed, help control direct glare.

Re-strike time:  usually applied to HID light sources, the interval between the extinguishing of an arc and the time it can he re-ignited.

Screw base compact fluorescent lamp:   a compact fluorescent lamp that has a ballast and a medium screw base that fits into a standard incandescent lamp socket. A screw base compact fluorescent lamp may be modular (lamp and ballast are separate pieces) or self-ballasted (lamp and ballast are integrated). Both types are designed to directly replace incandescent lamps.

Sky glow:    a result of scattered light in the atmosphere above urban areas.

Slimline lamps:    the name for a family of T12 fluorescent lamps operating at 425 milliamperes (mA). These two-pin lamps are designed to operate on instant start circuits, and are most commonly available in 4 and 8-foot lengths. See also instant-start circuit.

Spectra:    wavelengths of electromagnetic radiation.

Specular surface:    a shiny, mirror-like surface that produces a predominantly directional reflection.

Spot lamp:    a lamp that provides a relatively narrow beam of light.

Time clock:  a switch designed to automatically turn lights on and off over a daily, weekly, or yearly schedule predetermined by the user.

Timer:  see interval timer.

Tungsten halogen lamp:  see halogen lamp.

UL:  Underwriters Laboratories. An organization that tests electrical components and appliances and lists products that pass safety standards.

Ultrasonic (motion detector):     a device that transmits high-frequency vibrations, which are similar to sound waves but above the range of human hearing. These are reflected by objects back to a receiver Movement produces changes in frequency that are detected and activate a luminaire or alarm.

Ultraviolet (UV) radiation:  any radiant energy within the wavelength range of 100 to 400 nanometers (1 nanometer = I billionth of a meter, or I X 1O-9 meters).

Uniformity:    in outdoor lighting, a measure indicating how evenly light is distributed across a surface. Typically the measure is expressed as a ratio of one value to another, such as average to minimum, or maximum to minimum. Using ratios, perfect uniformity would be 1:1.

Voltage:   the difference in electrical potential that causes current flow in a circuit.

Warm-up time:  the time for a light source to reach full light output, often defined by manufacturers as 80 or 90 percent of full light output, after it has been energized.

Watt:    unit of real electric power; the rate at which electric energy is used.

Watt-hour:  unit of electric energy. One watt-hour is the amount of energy consumed at the rate of 1watt during a 1-hour period. See also kilowatt-hour.

Wavelength:   the distance between two corresponding points of a given wave. Wavelengths of light are measured in nanometers (1 nanometer = 1billionth of a meter, or 1 x lO-9 meters).

Wind Loading:   a rating of the ability of a luminaire and pole to withstand wind. Factors considered include pole height, material, and thickness as well as luminaire size and shape.