Crestron Lighting Software

Appendix D

DOWNLIGHT: A type of ceiling luminaire, usually fully recessed, where most of the light is directed downward. May feature an open reflector and/or shielding device

E

EFFICACY: A metric used to compare light output to energy consumption. Efficacy is measured in lumens per watt. Efficacy is similar to efficiency, but is expressed in dissimilar units. For example, if a 100-watt source produces 9000 lumens, then the efficacy is 90 lumens per watt

ELECTROLUMINESCENT: A light source technology used in exit signs that provides uniform brightness, long lamp life (approximately eight years), while consuming very little energy (less than one watt per lamp)

ELECTRONIC BALLAST: A ballast that uses semi-conductor components to increase the frequency of fluorescent lamp operation (typically in the 20-40 kHz range. Smaller inductive components provide the lamp current control. Fluorescent system efficiency is increased due to high frequency lamp operation

ELECTRONIC DIMMING BALLAST: A variable output electronic fluorescent ballast

ELECTRONIC LOW-VOLTAGE (ELV): Electronic low-voltage lighting uses an electronic (solid-state technology) transformer to convert line voltage (120 VAC) to low voltage (typically 12 VAC). This lower voltage is then used power an incandescent low-voltage lamp. Track lights are usually electronic low-voltage

EMI: Abbreviation for electromagnetic interference. EMI is the high frequency interference (electrical noise) caused by electronic components or fluorescent lamps that interferes with the operation of electrical equipment. EMI is measured in micro-volts, and can be controlled by filters. Because EMI can interfere with communication devices, the Federal Communication Commission (FCC) has established limits for EMI

ENERGY-SAVING BALLAST: A type of magnetic ballast designed so that the components operate more efficiently, cooler and longer than”standard magnetic" ballast. By US law, standard magnetic ballasts can no longer be manufactured

ENERGY-SAVING LAMP: A lower wattage lamp, generally producing fewer lumens

F

FC: (SEE FOOTCANDLE)

FLUORESCENT LAMP: A light source consisting of a tube filled with argon, along with krypton or other inert gas. When electrical current is applied, the resulting arc emits ultraviolet radiation that excites the phosphors inside the lamp wall, causing them to radiate visible light

FOOTCANDLE (FC): The English unit of measurement of the illuminance (or light level) on a surface. One footcandle is equal to one lumen per square foot

FOOTLAMBERT: English unit of luminance. One footlambert is equal to 1/p candelas per square foot.

FORWARD PHASE DIMMING: Rather than attempting to restrict the amplitude of the current flowing through a lamp, as in other forms of dimming, forward phase control works by switching off the beginning part of each cycle of the alternating current supply

FOUR-WIRE 10V ANALOG SIGNAL DIMMING: Two power wires (switched hot and neutral) and two additional control wires that are connected to a low-voltage circuit. Note: these ballasts do not turn on and off like DALI ballasts, so in addition to the low-voltage-level control circuit, they must also have a line-voltage switch. Zero to ten-volt control is a low-voltage DC dimming method. Power wires are rated Class 1 and control wires are rated Class 2. This separation allows multiple circuits to use the same dimming signal without additional power equipment

G

GLARE: The effect of brightness or differences in brightness within the visual field sufficiently high to cause annoyance, discomfort or loss of visual performance

H

HALOGEN: (SEE TUNGSTEN HALOGEN LAMP)

HARMONIC DISTORTION: A harmonic is a sinusoidal component of a periodic wave having a frequency that is a multiple of the fundamental frequency. Harmonic distortion from lighting equipment can interfere with other appliances and the operation of electric power networks. The total harmonic distortion (THD) is usually expressed as a percentage of the fundamental line current. THD for 4-foot fluorescent ballasts usually range from 20% to 40%. For compact fluorescent ballasts, THD levels greater than 50% are not uncommon

HID: Abbreviation for high intensity discharge. Generic term describing mercury vapor, metal halide, high-pressure sodium, and (informally) low-pressure sodium light sources and luminaires

HIGH BAY: Pertains to the type of lighting in an industrial application where the ceiling is 20 feet or higher. Also describes the application itself

HIGH OUTPUT (HO): A lamp or ballast designed to operate at higher currents (800 mA) and produce more light.

HIGH POWER FACTOR: Ballast with a 0.9 or higher rated power factor, which is achieved by using a capacitor.

HIGH PRESSURE SODIUM LAMP: A high intensity discharge (HID) lamp whose light is produced by radiation from sodium vapor (and mercury)

HOT RESTART or HOT RESTRIKE: The phenomenon of re-striking the arc in an HID light source after a momentary power loss. Hot restart occurs when the arc tube has cooled a sufficient amount

I

IESNA: Abbreviation for Illuminating Engineering Society of North America.

ILLUMINANCE: A photometric term that quantifies light incident on a surface or plane. Illuminance is commonly called light level. It is expressed as lumens per square foot (footcandles), or lumens per square meter (lux)

INDIRECT GLARE: Glare produced from a reflective surface.

INSTANT START: A fluorescent circuit that ignites the lamp instantly with a very high starting voltage from the ballast. Instant start lamps have single-pin bases

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Crestron electronic Residential Lighting manual Crestron Lighting Software Appendix D