Electrical wiring in the context of "Electrician"

A wall is a structure and a surface that defines an area; carries a load; provides security, shelter, or soundproofing; or serves a decorative purpose. There are various types of walls, including border barriers between countries, brick walls, defensive walls in fortifications, and retaining walls that hold back dirt, stone, water, or noise. Walls can also be found in buildings, where they support roofs, floors, and ceilings, enclose spaces, and provide shelter and security.

The construction of walls can be categorized into framed walls and mass-walls. Framed walls transfer the load to the foundation through posts, columns, or studs and typically consist of structural elements, insulation, and finish elements. Mass-walls are made of solid materials such as masonry, concrete, adobe, or rammed earth. Walls may also house utilities like electrical wiring or plumbing and must conform to local building and fire codes.

A printed circuit board (PCB), also called printed wiring board (PWB), is a laminated sandwich structure of conductive and insulating layers, each with a pattern of traces, planes and other features (similar to wires on a flat surface) etched from one or more sheet layers of copper laminated onto or between sheet layers of a non-conductive substrate. PCBs are used to connect or "wire" components to one another in an electronic circuit. Electrical components may be fixed to conductive pads on the outer layers, generally by soldering, which both electrically connects and mechanically fastens the components to the board. Another manufacturing process adds vias, metal-lined drilled holes that enable electrical interconnections between conductive layers, to boards with more than a single side.

Printed circuit boards are used in nearly all electronic products today. Alternatives to PCBs include wire wrap and point-to-point construction, both once popular but now rarely used. PCBs require additional design effort to lay out the circuit, but manufacturing and assembly can be automated. Electronic design automation software is available to do much of the work of layout. Mass-producing circuits with PCBs is cheaper and faster than with other wiring methods, as components are mounted and wired in one operation. Large numbers of PCBs can be fabricated at the same time, and the layout has to be done only once. PCBs can also be made manually in small quantities, with reduced benefits.

In electrical engineering, electromagnetic shielding is the practice of reducing or redirecting the electromagnetic field (EMF) in a space with barriers made of conductive or magnetic materials. It is typically applied to enclosures, for isolating electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs (see Shielded cable). Electromagnetic shielding that blocks radio frequency (RF) electromagnetic radiation is also known as RF shielding.

Practical field measurements in residential bedrooms typically use consumer EMF meters to determine local exposure levels.

The steppe eagle (Aquila nipalensis) is a large bird of prey. Like all eagles, it belongs to the family Accipitridae. The steppe eagle's well-feathered legs illustrate it to be a member of the subfamily Aquilinae, also known as the "Booted eagles". This species was once considered to be closely related to the sedentary tawny eagle (Aquila rapax) and the two forms have previously been treated as conspecific. They were split based on pronounced differences in morphology and anatomy; two molecular studies, each based on a very small number of genes, indicate that the species are distinct but disagree over how closely related they are.

The Steppe eagle is in many ways a peculiar species of eagle. It is a specialized predator of ground squirrels on the breeding ground, also taking other rather small mammals and other prey, doing so more often when ground squirrels are less consistently found. In rather treeless areas of the steppe habitats, these eagles tend to nest on a slight rise, often on or near an outcrop, but may even be found on flat, wide-open ground, in a rather flat nest. They are the only eagle to nest primarily on the ground. Usually, one to three eggs are laid and, in successful nests, one to two young eagles fledge. The steppe eagle undertakes a massive migration from essentially its entire breeding range, moving en masse past major migration flyways, especially those of the Middle East, Red Sea and the Himalayas. In winter, though less closely studied than during breeding, the steppe eagle is remarkable for its sluggish and almost passive feeding ecology, focusing on insect swarms, landfills, carrion and the semi-altricial young of assorted animals, lacking the bold and predatory demeanor of their cousin species. Although still seen by the thousands at migration sites in larger numbers than other migrating eagles of these areas, the steppe eagle's entire population has declined precipitously. The threats to this species consist of increasing steppe fires and pests around the nests (both probably increased by the warming climate) which can cause a large volume of nest failures. Rivaling these factors, declines are being exacerbated by disturbance and persecution by humans, as well as trampling of nests by livestock. Free-flying steppe eagles are also being killed in alarmingly large numbers, especially in the stronghold nation for breeding of Kazakhstan, by electrocutions on dangerous electricial wires and pylons. Due to these and other reasons, the decline of the species is thought to be considerably more than 50%. Therefore, the species is considered to be endangered by the IUCN. The steppe eagle appears on the flag of Kazakhstan and is the national bird of both Kazakhstan and Egypt.

An electrical conduit is a tube used to protect and route electrical wiring in a building or structure. Electrical conduit may be made of metal, plastic, fiber, or fired clay. Most conduit is rigid, but flexible conduit is used for some purposes. Conduit is generally installed by electricians at the site of installation of electrical equipment. Its use, form, and installation details are often specified by wiring regulations, such as the US National Electrical Code (NEC) and other building codes.

A polyphase system (the term coined by Silvanus Thompson) is a means of distributing alternating-current (AC) electrical power that utilizes more than one AC phase, which refers to the phase offset value (in degrees) between AC in multiple conducting wires; phases may also refer to the corresponding terminals and conductors, as in color codes. Polyphase systems have two or more energized electrical conductors carrying alternating currents with a defined phase between the voltage waves in each conductor. Early systems used 4 wire two-phase with a 90° phase angle, but modern systems almost universally use three-phase voltage, with a phase angle of 120° (or 2π/3 radians).

Polyphase systems are particularly useful for transmitting power to electric motors which rely on alternating current to rotate. Three-phase power is used for industrial applications and for power transmission. Compared to a single-phase, two-wire system, a three-phase three-wire system transmits three times as much power for the same conductor size and voltage, using only 1.5 times as many conductors, making it twice as efficient in conductor utilization.

Copper has been used in electrical wiring since the invention of the electromagnet and the telegraph in the 1820s. The invention of the telephone in 1876 created further demand for copper wire as an electrical conductor.

Copper is the electrical conductor in many categories of electrical wiring. Copper wire is used in power generation, power transmission, power distribution, telecommunications, electronics circuitry, and countless types of electrical equipment. Copper and its alloys are also used to make electrical contacts. Electrical wiring in buildings is the most important market for the copper industry. Roughly half of all copper mined is used to manufacture electrical wire and cable conductors.