GLOSSARY - S

 


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Satin Finish

Slightly textured or brushed surface having a fine grain that reflects light with some diffusion.

SCCR or S.C.C.R. or Short Circuit Current Rating

SCCR or “short circuit current rating” is a rating of how much over-current a device can take without injuring equipment or personnel. SCCR is applied to a passive device such as a relay that doesn’t have its own way to “open”. 


Scene

Specific setting for a group of dimmer channels or zone. A multi-scene control allows you to select the different setting by pushing a button.

The lighting effect created by adjusting several zones/channels of lighting to the desired intensity.


Sconce

Wall bracket fixture derived from the form of a candelabra, often with exposed or decorative light sources.

Sequencing

The mode during which preset lighting scenes change in a designated order using fade times that have been programmed.

Setpoint Optimization (also called Trim and Respond)

A control strategy that optimizes the setpoint of a source piece of equipment that supplies one or more receiving units - such as an air handler unit supplying zone terminal units with heating, cooling, ventilation, or similar service.

The source unit communicates with receiving units to determine heating, cooling, and other requirements, and then adjusts its setpoint.

For example, if all zones are comfortable and do not request cooling, the AHU will gradually increase (trim) its supply air setpoint. When a zone requests cooling, the AHU responds by dropping its setpoint. The more zones that request cooling, the more it drops the setpoint. The AHU repeats this process throughout the day to keep zones cool, but with a supply air setpoint that is no cooler than necessary.


Silhouetting

Accent lighting technique that creates a dramatic outline by back lighting. Also used in landscape lighting.

Slide Dimmers

Slide dimmers operate via a slide toggle, providing a full-range of manual dimming control. Some are equipped with a touch-button that allows you to return to the previous lighting level. Others have an indicator light that glows in the dark for easy location.

Sloped Ceilings

The flexibility of track lighting can be a major help when trying to light from a sloped ceiling. Most recessed fixtures cannot be aimed to light art on an adjacent wall, while track lighting fixtures allow you to do so easily.


SMACNA

Sheet Metal and Air Conditioning Contractors National Association, Inc. is an international association of HVAC contractors. Its headquarters is at 4201 Lafayette Center Drive Chantilly, Virginia 20151-1209, and it has about 2,000 members and 98 chapters in the United States, Canada, Brazil, and Australia.

Sheet Metal and Air Conditioning Contractors National Association, Inc.
4021 Lafayette Center Drive
Chantilly, VA 20151-1209

http://www.smacna.org/


Soffit

In architecture, the underside of an overhead component, such as an arch, cornice, beam or balcony. Often used to describe an area of the ceiling that drops below the primary surface.

Smart Actuator (SA)

An actuator which is controlled by a network connection rather than a binary or analog signal. (0-10v, 4-20mA, relay, etc.)

Smart Sensor (SS)

A sensor which provides information to the BAS via network connection rather than a binary or analog signal. (0-10000 ohm, 4-20mA, dry contact, etc.)

Solid State

Electronics that use semi-conductor chips and circuitry.

Solid-state electronic components, devices, and systems are based entirely on the semiconductor, such as transistors, microprocessor chips, and the bubble memory. In solid-state components, there is no use of the electrical properties of a vacuum and no mechanical action, no moving parts, although a considerable amount of electromagnetic and quantum-mechanical action takes place within.

In a solid-state component, the current is confined to solid elements and compounds engineered specifically to switch and amplify it. Current flows in two forms: as negatively-charged electrons, and as positively-charged electron deficiencies called electron holes or just "holes". In some semiconductors, the current consists mostly of electrons; in other semiconductors, it consists mostly of "holes". Both the electron and the hole are called charge carriers.


Specular Finish

Highly polished and mirror-like. Semi-specular finish is generally bright, but without a well-defined mirror image.

Spot Lamp

Reflectorized lamp with a narrow light distribution.

Squares

Short for recessed square downlights, which are usually shallow fixtures with diffusers or lenses.

Step Lights

Step Lights are recessed into walls and stairs so they illuminate the treads of stairs or pathways. An eye shield is often used to block direct view of the light source.

Surface Mounted

Surface-mounted fixtures are also know as ceiling mounted fixtures. They attach directly or close to the ceiling. The light distribution is often semi-direct or general diffuse.

Switch Leg

Wiring that connects the switch or dimmer output to the fixture or load being controlled.