Crestron Lighting Design Guía de instalación descargar pdf (Pagina 73)

230 V Lighting Design Guide

Doc. 4859C | crestron.com

COLOR RENDITION: The appearance of colors when illuminated by a light source. Color rendition is generally

considered to be a more important lighting quality than color temperature. Most objects are not a single color, but a

combination of many colors. Light sources that are deﬁcient in certain colors can change the apparent color of an

object. The Color Rendition Index (CRI) is a 1–100 scale that measures a light source's ability to render colors the

same way sunlight does. The top value of the CRI scale (100) is based on illumination by a 100 watt incandescent

light bulb. A light source with a CRI of 80 or higher is considered acceptable for most indoor residential applications.

COLOR TEMPERATURE: The speciﬁcation of the color appearance of a light source, relating the color to a reference

source heated to a particular temperature, measured by the thermal unit Kelvin. The measurement can also be

described as the warmth or coolness of a light source. Generally, sources below 3200 K are considered warm,

while those above 4000 K are considered cool sources.

COMPACT FLUORESCENT: A small ﬂuorescent lamp that is often used as an alternative to incandescent lighting.

The lamp life is about 10 times longer than incandescent lamps and is 3-4 times more efﬁcacious. Also called PL,

Twin-Tube, CFL, or BIAX lamps.

CONSTANT WATTAGE (CW) BALLAST: A premium type of HID ballast in which the primary and secondary coils are

isolated. It is considered a high performance, high loss ballast featuring excellent output regulation.

CONSTANT WATTAGE AUTOTRANSFORMER (CWA) BALLAST: A popular type of HID ballast in which the primary and

secondary coils are electrically connected. Considered an appropriate balance between cost and performance.

CONTRAST: The relationship between the luminance of an object and its background.

CUT-OFF ANGLE: The angle from a ﬁxture's vertical axis at which a reﬂector, louver, or other shielding device cuts

off direct visibility of a lamp. It is the complementary angle of the shielding angle.

DAYLIGHT COMPENSATION: A dimming system controlled by a photocell that reduces the output of the lamps when

daylight is present. As daylight levels increase, lamp intensity decreases. An energy-saving technique used in areas

with signiﬁcant daylight contribution.

DERATING: Components can be treated in such a way as to enhance their life expectancy. Derating is the name

normally given to operating a component well inside its normal operating limits to extend the life of a component,

and is a practical means of reducing failures. The National Electrical Code and local electrical codes determine the

amount of available current based on a derating factor. A derating factor improves reliability by reducing the upper

limit of current carrying capacity to compensate for electrical, mechanical and thermal stress.

DIFFUSE: Term describing dispersed light distribution. Refers to the scattering or softening of light.

DIFFUSER: A translucent piece of glass or plastic sheet that shields the light source in a ﬁxture. The light

transmitted throughout the diffuser is redirected and scattered.

DIRECT GLARE: Glare produced by a direct view of light sources. Often the result of insufﬁciently shielded light

sources. (See GLARE)

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.

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Crestron Lighting Design Guía de instalación Pagina 73