Georgia Low Voltage Practice key terms

The fixed relationship among voltage, current, and resistance in a circuit, expressed as voltage equals current times resistance. Knowing any two values lets you calculate the third for troubleshooting and sizing conductors.

The relationship stating that electrical power in watts equals voltage multiplied by current, with a power-factor correction for alternating-current loads. Used to estimate load on circuits and power supplies.

The loss of voltage along a conductor caused by its resistance, which increases with length, current, and smaller wire size. Excessive drop causes devices to malfunction and is limited by design guidelines.

The standard numbering system for conductor size in North America, where smaller numbers indicate larger conductors. Common low voltage sizes include 22, 18, 16, and 14 AWG.

A circuit supplied by a listed limited-power source, such as a transformer or power supply, that limits energy to levels considered safe for fire and shock under normal conditions. Most low voltage signaling and control wiring falls in this category.

A circuit supplied by a listed power source with energy limits higher than Class 2 but still controlled, used for certain remote-control and signaling applications. Its wiring rules differ from Class 2 in separation and permitted uses.

A circuit whose source is listed and restricts available energy to safe levels, allowing reduced wiring methods and fewer protection requirements. The installer must confirm the source listing rather than assume from low voltage alone.

A space used for air handling, such as above a suspended ceiling that serves as a return-air path. Cable installed there must have a plenum rating because of fire and smoke concerns.

A communications cable listing indicating low smoke and flame spread, suitable for installation in ducts and plenums. It is the most restrictive and typically most expensive jacket rating.

A communications cable listing intended for vertical runs between floors in shafts, offering flame resistance for riser applications. It is not permitted in plenums unless also plenum rated.

A vertical pathway, such as a shaft or chase, that carries cables between floors of a building. Cables installed there must carry the appropriate riser rating.

The percentage of a raceway's internal cross-section occupied by cables or conductors. Limits keep pulling tension reasonable and prevent heat buildup or damage during installation.

The longitudinal force applied to a cable while pulling it through a raceway or conduit. Exceeding the manufacturer's limit stretches conductors, changes impedance, and degrades data performance.

The minimum curve a cable can tolerate without damage, usually stated as a multiple of its outer diameter. Violating it kinks conductors, cracks insulation, and degrades signal performance.

A performance classification for twisted-pair cable and components, such as Category 5e, 6, or 6A, specifying supported frequencies and data rates. Higher categories demand tighter installation and testing tolerances.

The installed portion of a cabling run from the work-area outlet to the patch panel, excluding patch cords. It is the standard test configuration for verifying installed performance.

The complete end-to-end signal path, including the permanent link plus patch cords at both ends. Channel testing reflects real-world performance but is less repeatable than link testing.

Unwanted signal coupling from one pair or cable to another, measured as near-end or far-end values. It is the primary impairment in twisted-pair cabling and is controlled by twist rates and installation care.

The widely adopted North American standard series governing commercial structured cabling design, installation, and performance. It defines cable categories, distances, topologies, and test requirements.

A cabling layout in which each work area connects by a dedicated cable to a central distribution point. It supports easy moves, adds, and changes and is the basis of structured cabling standards.

The cabling from the telecommunications room to work-area outlets on the same floor, limited in length by standards. It excludes backbone and patch cords in its length budget.

A rack-mounted assembly of ports where horizontal cables terminate and are cross-connected to network equipment. It provides organization, labeling, and flexibility for changes.

The central unit that monitors initiating devices, controls notification appliances, and reports system status and alarms. It may be conventional, addressable, or networked, and its programming must match the approved design.

The wiring loop connecting detectors and manual pull stations to the fire alarm panel. Conventional circuits report by zone, while addressable circuits identify individual devices.

The circuit that powers horns, strobes, and speakers, requiring supervision and adequate voltage at the end of the line. Voltage drop calculations are critical because appliances must operate at their listed minimum.

A detector, module, or appliance that has its own unique address on a signaling line circuit, allowing individual identification. Addressable systems simplify troubleshooting and support detailed annunciation.

The addressable data and power pathway connecting intelligent devices to the fire alarm panel. It requires specific cable types and supervision to detect opens, shorts, and ground faults.

A monitoring method that detects opens, shorts, or ground faults on wiring so a failure is annunciated rather than silently disabling protection. It is required for most fire alarm and life safety circuits.

A component that shunts or clamps transient overvoltages to protect equipment, rated by surge current capacity and clamping voltage. Proper installation requires short, low-impedance leads and correct grounding.

The set of electrodes, such as rods, plates, or building steel, that establishes a connection to earth. It provides a reference and path for lightning and fault currents.

A conductor that intentionally connects metal parts to ensure electrical continuity and equal potential. It is distinct from a grounding conductor, which carries current to earth.

Connecting conductive surfaces together so they sit at the same potential, preventing dangerous voltage differences. It is essential in communications rooms and around sensitive electronics.

An unintended path from a current-carrying conductor to earth or metalwork, which can cause shock, fire, or nuisance tripping. Ground fault detection is required on many fire alarm circuits.

A safety procedure that isolates energy sources and applies locks and tags to prevent unexpected energization during work. Only the person who applied the lock should remove it under normal circumstances.

Wearable safety gear such as eye protection, gloves, and hard hats selected for the hazards of the task. It supplements, but never replaces, safe work practices and engineering controls.

A space with limited entry or exit that is not designed for continuous occupancy, such as a vault or crawlspace. Entry may require atmospheric testing, a permit, and an attendant.

The set of practices for selecting, setting, and using ladders, including the four-to-one angle rule and three-point contact. It prevents falls, the leading cause of serious injury in the trade.

The Georgia state board that issues licenses for electrical and low voltage contractors and enforces qualification requirements. It sets examination, insurance, and continuing education rules.

The Georgia credential authorizing a business to contract for low voltage work such as alarm, communications, and control systems. It generally requires a qualifying agent, insurance, and board approval.

An individual who holds the required license and is responsible for the technical competence and code compliance of a contracting business. The business license depends on that person's standing.

Required periodic training hours that license holders complete to renew their credential and stay current. Hours must come from approved providers and be documented for audit.

The legal framework in Georgia governing written agreements, payment terms, and a contractor's ability to place a lien for unpaid work. Missing notices or deadlines can forfeit those rights.