ELECTRICAL ENCYCLOPEDIA

What is an Arc Flash?   Arc flash temperatures can reach or exceed 35,000 F at the arc terminals. The massive energy released in the fault rapidly vaporizes the metal conductors involved, blasting molten metal and expanding plasma outward with extreme force. A typical arc flash incident can be inconsequential but could conceivably easily produce a more severe explosion (see calculation below). The result of the violent event can cause destruction of equipment involved, fire, and injury not only to the worker but also to nearby people. continue.. Where does Arc Flash come from?   Arc Flash is the result of a rapid release of energy due to an arcing fault between a phase bus bar and another phase bus bar, neutral or a ground. During an arc fault the air is the conductor. Arc faults are generally limited to systems where the bus voltage is in excess of 120 volts. Lower voltage levels normally will not sustain an arc. An arc fault is similar to the arc obtained during electric welding

What is the basic definition of a Surge?   A surge is a sudden gust of something or a very sudden and dramatic increase. (noun). To surge is to quickly and suddenly move as part of a crowd, to increase rapidly and suddenly, or to cause someone to feel sudden and powerful emotions. (verb) continue.. What is a Surge Protector?   A surge protector (or surge suppressor) is an appliance designed to protect electrical devices from voltage spikes. A surge protector attempts to limit the voltage supplied to an electric device by either blocking or by shorting to ground any unwanted voltages above a safe threshold. This article primarily discusses specifications and components relevant to the type of protector that diverts (shorts) a voltage spike to ground; however, there is some coverage of other methods. continue.. How does a Surge Protector Works?   When you put together a computer system, one piece of standard equipment you'll probably buy is a surge protector. Most designs serve

How is a Plane Protected from Lightning?   Most aircraft do not fly into lightning storms, or fly through storms or areas where lightning is likely to be present. What we see as lightning is really a massive flood of electrons seeking equilibrium, either from cloud-cloud or from cloud-ground. In both cases, huge amounts of electric charge build up at the edges of the cloud. The electricity finds it's way from one place to the other via what's called a "step leader". continue.. Lightning Strike Protection for Carbon Fiber Aircraft   Lightning strikes on transport aircraft happen periodically depending on many parameters including atmospheric conditions and operational characteristics of the airplane. Most recent nacelle fleet history, circa 2002-2005, has shown that lightning strike damage has occurred more frequently on shorter mission commercial aircraft equipped with composite panels than prior configurations of nacelle panels. It should be noted that the great

What is a Ground (electricity)?   Electrical circuits may be connected to ground (earth) for several reasons. In mains powered equipment, exposed metal parts are connected to ground to prevent contact with a dangerous voltage if electrical insulation fails. Connections to ground limit the build-up of static electricity when handling flammable products or when repairing electronic devices. In some telegraph and power transmission circuits, the earth itself can be used as one conductor of the circuit, saving the cost of installing a separate return conductor. continue.. How Electrical Grounding Works   Grounding, Electrical, the connecting of electrical equipment and wiring systems to the earth by a wire or other conductor The primary purpose of grounding is to reduce the risk of serious electric shock from current leaking into uninsulated metal parts of an appliance, power tool, or other electrical device. In a properly grounded system, such leaking current (called fault current) is

What is a Wire?   A wire is a single, usually cylindrical, flexible strand or rod of metal. Wires are used to bear mechanical loads and to carry electricity and telecommunications signals. Wire is commonly formed by drawing the metal through a hole in a die or draw plate. Standard sizes are determined by various wire gauges. The term wire is also used more loosely to refer to a bundle of such strands, as in 'multistranded wire', which is more correctly termed a wire rope in mechanics, or a cable in electricity. continue.. FAQs on Wire Types and Sizes   Most electrical wire is covered in a rubber or plastic coating called insulation. What is the purpose of having this ïnsulation" covering the metal wire? In the early days of electrical wiring, wires used to be insulated with cotton. This is no longer accepted practice. Explain why. Electrical wire is often rated according to its cross-sectional diameter by a gauge scale. Which is the larger-diameter wire size, 14 gauge

What is a Ferrite Bead?   A ferrite bead is a passive electric component used to suppress high frequency noise in electronic circuits. It is a specific type of electronic choke. Ferrite beads employ the mechanism of high dissipation of high frequency currents in a ferrite to build high frequency noise suppression devices. Ferrite beads may also be called ferrite blocks, ferrite cores, ferrite rings, ferrite EMI filters, ferrite chokes or ferrous beads.. continue.. What are ferrite beads made for?   A ferrite bead is simply a hollow bead or cylinder made of ferrite, which is a semi-magnetic substance made from iron oxide (rust) alloyed with other metals. It slips over the cable when the cable is made, or it can be snapped around the cable in two pieces after the cable is made. The bead is encased in plastic -- if you cut the plastic, all that you would find inside is a black metal cylinder.. continue.. Disadvantages of Ferrite   Ferrites are substances derived from a mix of iron o

What is Wi-Fi?   Wi-Fi ( /ˈwaɪfaɪ/) or Wifi, is a mechanism for wirelessly connecting electronic devices. A device enabled with Wi-Fi, such as a personal computer, video game console, smartphone, tablet, or digital audio player, can connect to the Internet via a wireless network access point. An access point (or hotspot) has a range of about 20 meters (65 ft) indoors and a greater range outdoors. Multiple overlapping access points can cover large areas. continue.. Brief History of Wi-Fi   In the beginning-Wi-Fi would certainly not exist without a decision taken in 1985 by the Federal Communications Commission (FCC), America's telecoms regulator, to open several bands of wireless spectrum, allowing them to be used without the need for a government licence. This was an unheard-of move at the time; other than the hamradio channels, there was very little unlicensed spectrum. But the FCC, prompted by a visionary engineer on its staff, Michael Marcus, took three chunks of spectrum fr