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Knob And Tube Wiring
Knob-and-tube wiring (sometimes abbreviated K&T) is an early standardized method of electrical wiring in buildings, in common use in North America from about 1880 to the 1930s. It consisted of single-insulated copper conductors run within wall or ceiling cavities, passing through joist and stud drill-holes via protective porcelain insulating tubes, and supported along their length on nailed-down porcelain knob insulators. Where conductors entered a wiring device such as a lamp or switch, or were pulled into a wall, they were protected by flexible cloth insulating sleeving called loom. The first insulation was asphalt-saturated cotton cloth, then rubber became common. Wire splices in such installations were twisted together for good mechanical strength, then soldered and wrapped with rubber insulating tape and friction tape (asphalt saturated cloth), or made inside metal junction boxes. Knob and tube wiring was eventually displaced from interior wiring systems because of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Knob And Tube 1930
Knob or KNOB may refer to: Objects * A round handle ** Doorknob ** Control knob, controls a device ** Brodie knob, on a steering wheel * Tow ball or hitch ball * Dorset knob, a biscuit Landforms * A rounded hill or mountain, particularly in the Appalachians and the Ozarks ** List of geographical knobs ** The Knob (other), several individual knobs with the name * A knob is also a kame, which is a mound left behind by a glacier * Knobs region, a geographic region of Kentucky, locally known as "The Knobs", consisting of hundreds of isolated hills Radio stations * KNOB (FM), a radio station (96.7 FM) licensed to Healdsburg, California, United States * KSFN, a radio station (1510 AM) licensed to Piedmont, California, United States, which held the call sign KNOB from 1995 to 1997 * KJPG, a radio station (1050 AM) licensed to Frazier Park, California, United States, which held the call sign KNOB from 1988 to 1994 * KLAX-FM, a radio station (97.9 FM) licensed to Long Beach, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ground And Neutral
In electrical engineering, ground (or earth) and neutral are circuit conductors used in alternating current (AC) electrical systems. The neutral conductor carries alternating current (in tandem with one or more ''phase '' conductors) during normal operation of the circuit. By contrast, a ground conductor is not intended to carry current for normal operation, but instead connects exposed conductive parts (such as equipment enclosures or conduits enclosing wiring) to Earth (the ground), and only carries significant current in the event of a circuit fault that would otherwise energize exposed conductive parts and present a shock hazard. In such case the intention is for the fault current to be large enough to trigger a circuit protective device that will either de-energize the circuit, or provide a warning. To limit the effects of leakage current from higher-voltage systems, the neutral conductor is often connected to earth ground at the point of supply. Significant voltage unin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
T-splice
In electrical wiring, a T-splice is a splice that is used for connecting the end of one wire to the middle of another wire, thus forming a shape like that of the letter "T". This splice can be used with solid or stranded wires. The existing wire is called the main wire. The new wire that connects to the main wire is called the branch wire or tap wire. This is a prevalent junction type used in knob and tube wiring. See also * Rat-tail splice * Western Union splice * Wire wrap Close-up of a wire-wrap connection Typical wire wrap construction of crossbar_switch.html" ;"title="Bell System telephone crossbar switch">Bell System telephone crossbar switch. Some types of connection were soldered. Wire wrap is an electron ... References {{Splicing Telecommunications equipment Electrical wiring Splices ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rat-tail Splice
A rat-tail splice, also known as a twist splice or a pig-tail splice, is a basic electrical splice that can be done with both solid wire, solid and stranded wire. It is made by taking two or more bare wires and wrapping them together symmetry, symmetrically around the common axis of both wires. The bare splice can be insulated with electrical tape or by other means. This common and simple splice is not very strong mechanically. It can be made stronger by coating it with solder, which, however, renders the splice less mechanically flexible, or it can be twisted and then held in place by the internal metal spring or threads of a twist-on wire connector, also called a wire nut. For safety reasons, neither covering the splice with tape only nor soldering the splice are permitted for 110 volts or higher by most, or all, North American building electrical codes. The rat-tail splice is not meant to connect wires that will be pulled or stressed. Rather, it is intended for wires that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Home Insurance
Home insurance, also commonly called homeowner's insurance (often abbreviated in the US real estate industry as HOI), is a type of property insurance that covers a private residence. It is an insurance policy that combines various personal insurance protections, which can include losses occurring to one's home, its contents, loss of use (additional living expenses), or loss of other personal possessions of the homeowner, as well as liability insurance for accidents that may happen at the home or at the hands of the homeowner within the policy territory. Additionally, homeowner's insurance provides financial protection against disasters. A standard home insurance policy covers the home and the belongings inside it. Overview Homeowner's policy is a multiple-line insurance policy, meaning that it includes both property insurance and liability coverage, with an indivisible premium, meaning that a single premium is paid for all risks. This means that it covers damage to one's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Building Insulation
Building insulation is material used in a building (specifically the building envelope) to reduce the flow of thermal energy. While the majority of insulation in buildings is for thermal insulation, thermal purposes, the term also applies to acoustic insulation, Fireproofing, fire insulation, and Cushioning, impact insulation (e.g. for vibrations caused by industrial applications). Often an Building insulation materials, insulation material will be chosen for its ability to perform several of these functions at once. Since prehistoric times, humans have created thermal insulation with materials such as animal fur and plants. With the agricultural development, earth, stone, and cave shelters arose. In the 19th century, people started to produce insulated panels and other artificial materials. Now, insulation is divided into two main categories: bulk insulation and reflective insulation. Buildings typically use a combination. Insulation is an important economic and environmenta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Electrical Code (US)
The National Electrical Code (NEC), or NFPA 70, is a regionally adoptable standard for the safe installation of electrical wiring and equipment in the United States. It is part of the National Fire Code series published by the National Fire Protection Association (NFPA), a private trade association. Despite the use of the term "national," it is not a federal law. It is typically adopted by states and municipalities in an effort to standardize their enforcement of safe electrical practices. In some cases, the NEC is amended, altered and may even be rejected in lieu of regional regulations as voted on by local governing bodies. The "authority having jurisdiction" inspects for compliance with the standards. The NEC should not be confused with the National Electrical Safety Code (NESC), published by the Institute of Electrical and Electronics Engineers (IEEE). The NESC is used for electric power and communication utility systems including overhead lines, underground lines, and pow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fuse (electrical)
In electronics and electrical engineering, a fuse is an electrical safety device that operates to provide overcurrent protection of an electrical circuit. Its essential component is a metal wire or strip that melts when too much current flows through it, thereby stopping or interrupting the current. It is a sacrificial device; once a fuse has operated, it is an open circuit, and must be replaced or rewired, depending on its type. Fuses have been used as essential safety devices from the early days of electrical engineering. Today there are thousands of different fuse designs which have specific current and voltage ratings, breaking capacity, and response times, depending on the application. The time and current operating characteristics of fuses are chosen to provide adequate protection without needless interruption. Wiring regulations usually define a maximum fuse current rating for particular circuits. A fuse can be used to mitigate short circuits, overloading, mismatched loads ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Three-way Switch
In building wiring, multiway switching is the interconnection of two or more electrical switches to control an electrical load from more than one location. A common application is in lighting, where it allows the control of lamps from multiple locations, for example in a hallway, stairwell, or large room. In contrast to a simple light switch, which is a single pole, single throw (SPST) switch, multiway switching uses switches with one or more additional contacts and two or more wires are run between the switches. When the load is controlled from only two points, single pole, double throw (SPDT) switches are used. Double pole, double throw (DPDT) switches allow control from three or more locations. In alternative designs, low-voltage relay or electronic controls can be used to switch electrical loads, sometimes without the extra power wires. Three-way and four-way switches The controlled load is often a lamp, but multiway switching is used to control other electrical loads ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ground Conductor
In electrical engineering, ground or earth may be a reference point in an electrical circuit from which voltages are measured, a common return path for electric current, or a direct physical connection to the Earth. Electrical circuits may be connected to ground for several reasons. Exposed conductive parts of electrical equipment are connected to ground to protect users from electrical shock hazards. If internal insulation fails, dangerous voltages may appear on the exposed conductive parts. Connecting exposed conductive parts to a "ground" wire which provides a low-impedance path for current to flow back to the incoming neutral (which is also connected to ground, close to the point of entry) will allow circuit breakers (or RCDs) to interrupt power supply in the event of a fault. In electric power distribution systems, a protective earth (PE) conductor is an essential part of the safety provided by the earthing system. Connection to ground also limits the build-up of static el ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
