The Foolproof What Are Electric Cables Strategy > 자유게시판

In our own country there is little doubt that the proper method of constructing electrical wires between cities is, to string them on poles in mid-air. Many of the European cities have the telegraph lines carried from the center of the city to the outskirts, under-ground; and, in Paris, not only all of the telegraph lines, but those for electric lights, telephones, and the various other private and municipal lines, are carried in the sewers under the streets of the city. Thus it happened that, though the first idea of telegraph engineers the world over was to run electric wires under-ground, they were everywhere obliged to string the wires on poles. When his visitor was gone, Mr. Field began to turn over a terrestrial globe which stood in his library, and it flashed upon him that the telegraph to Newfoundland might be extended across the Atlantic Ocean. In a circuit where multiple switches turn a light on and off from different locations, the red wire provides for this option. Red wires are sometimes used as the second hot wire in 240-volt installations. It is important to note that neutral wires may also be carrying power and can shock you. Common cables can be sheathed in metal or an insulating polymer.

Metal electrical boxes also need ground connection because they are made of a conductive material. Plastic boxes are non-conductive and do not need to be grounded. All electrical devices must be grounded. Ground screws on electrical devices are often painted green, too. Countries have different standards for color coding (based on the color of the wire’s insulation).In the US, black and red are typically designated as ‘hot’ wires, white or silver are used for neutral lines, what are electric cables and green or green with yellow stripes for ground wires. Power is delivered from the service Weather head to the building via the main feeder cables and wires. The use of wires and cables makes it possible for electricity to be used in many different places. Blue and yellow wire insulation is sometimes used to indicate hot wires inside an electrical conduit. Rarely are blue and yellow wires found within NM cable sheathing. Blue wires are commonly used for travelers in three-way and four-way switch applications. Older wires sometimes may lose their electrical tape wrapping. This white wire should be looped several times around with black electrical tape to show that it is being used for something other than a neutral. There are several thousand miles of wire in the sewers of Paris, and the cost of the gutta-percha-covered cables is about $140 per mile of wire, or about five times the cost of a pole line to do the same work.

When it was landed, the Reverend Mr. Day, of Kenmore, offered up a prayer, asking the Almighty to prosper the undertaking, Next day the expedition sailed; but ere the Niagara had proceeded five miles on her way the shore-end parted, and the repairing of it delayed the start for another day. For a day or two all went well; over two hundred miles of cable ran smoothly out of each vessel, and the anxious chiefs began to indulge in hopes of ultimate success, when the cable broke about twenty feet behind the stern of the Agamemnon. Color-coded electrical wires help you with future projects and make them easier to accomplish since you don't have to figure out the purpose of each wire. The Hughes, or the Stock Exchange instruments, for instance, print the message in Roman characters; the sounders strike it out on stops or bells of different tone; the needle instruments indicate it by oscillations of their needles; the Morse daubs it in ink on paper, or embosses it by a hard style; while Bain's electro-chemical receiver stains it on chemically prepared paper. While wires designated as hot (black or red insulated wires) carry power from the service panel (breaker box) to the device, neutral wires carry power back to the service panel.

Your home is less safe, too, because improperly connected wires may cause a fire. Being aware of electrical wire colors is valuable, too, since the electrical code requires that certain wires (neutral and ground) follow a standard color coding pattern. Thus, both hot and neutral wires have the potential to shock and injure you. If these wires are run on poles, they not only disfigure the streets, but seriously interfere with the operations of firemen in case of fire, as we have repeatedly seen during the last few years. With the wire under moderate tension to keep the wires taut, the drill can be turned. Another useful application for red wires is to interconnect hardwired smoke detectors so that if one alarm is triggered all of the others go off simultaneously. Typically, this is indicated with a band of black or red electrical tape wrapped around the wire's insulation. So, if the box has a loose loop of tape inside of it, there is the possibility that it may have come off of the neutral wire. When examining a white or gray wire, make certain that it has not been wrapped in electrical tape. White or gray wire insulation indicates a neutral wire.