Electric Wiring and LightingAmerican school of correspondence, 1908 - 180 стор. |
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Electric Wiring and Lighting American School (Chicago, Ill.),American School of Correspondence Повний перегляд - 1908 |
Electric Wiring and Lighting Chica American School of Correspondence Попередній перегляд недоступний - 2016 |
Electric Wiring and Lighting (Classic Reprint) American School Of Correspondence Попередній перегляд недоступний - 2017 |
Загальні терміни та фрази
alternating current alternating-current amount amperes arc lamps armored cable arranged battery beams bell branch circuit building calculating candle carbon ceiling cent coil connected cross-arms cut-out diameter direct current direct-current distance distribution curve drop ductors ducts efficiency enclosed arc feeders and mains feet fibre conduit filament Flexible Steel Conduit floor form of conduit formula fuse given glass globe glower ground illumination incandescent lamp inches installed iron conduits joint knob and tube length light sources linework load located loss manhole method of wiring moulding National Electric Code Nernst Lamp neutral conductor number of lamps obtained one-half Opal outlet-box outlets photometer placed poles porcelain power factor reactance reactance-volts reflector resistance-volts rigid conduit screen short circuit shown in Fig shows sizes of conductors skin effect surface switch TABLE three-wire system tion transformer tube wiring two-wire circuit two-wire system type of lamp usually Vitrified Conduit voltage voltmeter volts walls
Популярні уривки
Сторінка 14 - Rigid supporting requires under ordinary conditions, where wiring over flat surfaces, supports at least every four and one-half feet. If the wires are liable to be disturbed, the distance between supports should be shortened. In buildings of mill construction, mains of No.
Сторінка 36 - The test must be made with all cut-outs and safety devices in place. If the lamp sockets, receptacles, electroliers, etc., are also connected, only onehalf of the resistances specified in the table will be required.
Сторінка 12 - The feeding of the carbons may be done by hand, as is the case in some stereopticons using an arc, but for ordinary illumination the striking and maintaining of the arc must be automatic. It is made so in all cases by means of solenoids acting against the force of gravity or against springs. There are an endless number Fig.
Сторінка 45 - Therefore, for the problem taken, the drop is 18.7 per cent, and the loftn is 16 . 1 per cent. If the problem be to find the size wire for a given drop, it must be solved by trial. Assume a size of wire and calculate the drop ; the result in connection with the table will show the direction and extent of the change necessary in the size of wire to give the required drop. The effect of the line reactance in increasing the drop should be noted. If there were no reactance, the drop in the above example...
Сторінка 60 - In buildings already constructed, where the conditions are such that neither outlet -box nor plate can be installed, these appliances may be omitted by special permission of the inspection department having jurisdiction, providing the conduit ends are bushed and secured.
Сторінка 55 - " clear " 91.2 " " " opal " 85.1 ' " Opal " " opal " 82.7 « PHOTOMETRY. Photometry is the art of comparing the illuminating properties of light sources, and forms one branch of scientific measurement. Its use in electric illumination is to determine the relative values of different types of lamps as sources of illumination, together with their efficiency ; also by means of the principles of photometry, we are able to study the distribution of illumination for any given arrangement of light sources....
Сторінка 19 - They are always connected in series, and are run from some form of special arc machine, a description of which may be found in " Types of Dynamo Electric Machinery". Each lamp requires in the neighborhood of 50 volts for its operation, and, since the lamps are connected in series, the voltage of the system will depend on the number of lamps; therefore, the number of lamps that may be connected to one machine is limited by the maximum allowable voltage on that machine. By special construction as many...
Сторінка 34 - As a rulo, the internal resistance of the battery is so small in comparison with the resistance of the voltmeter and the external resistance, that it may be entirely neglected, and this will be done in the following calculation. In the second case, however, the total resistance in circuits is the resistance of the voltmeter and the battery, plus the entire insulation resistance on all the wires, etc., connected in circuit. To put this in mathematical form, the voltage of the cells may be indicated...
Сторінка 47 - STREET LIGHTING. In studying the lighting of streets and parks, we find that, except in special cases, such as narrow streets and high buildings, there is no reflected light which aids the illumination aside from that due to special shades or reflectors on the lamp itself. Such reflectors are necessary if the light ordinarily thrown above the horizontal plane is to be utilized. In calculating the illumination due to any type of lamp at a given point it is necessary to know the distribution curve...