Electric Lighting: A Practical Exposition of the Art, for the Use of Engineers, Students, and Others Interested in the Installation Or Operation of Electrical Plants, Том 2D. Van Nostrand Company, 1901 |
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Сторінка 3
... resistance . Metallic sodium is only about one - quarter as heavy as copper for equal length and resistance . Although there are several metals that could be used as elec- trical conductors which are considerably lighter than copper ...
... resistance . Metallic sodium is only about one - quarter as heavy as copper for equal length and resistance . Although there are several metals that could be used as elec- trical conductors which are considerably lighter than copper ...
Сторінка 4
... Resistance . In electrical distribution the most im- portant factor is resistance , from the scientific as well as from the commercial points of view . It entirely determines the flow of a direct current , and largely affects ...
... Resistance . In electrical distribution the most im- portant factor is resistance , from the scientific as well as from the commercial points of view . It entirely determines the flow of a direct current , and largely affects ...
Сторінка 5
... resistance of any copper wire at 20 de- grees C. or 68 degrees Fahr . , according to Matthiessen's standard , 10.35 / may be calculated by the following simple formula : R = d2 R being the resistance in international ohms , the length ...
... resistance of any copper wire at 20 de- grees C. or 68 degrees Fahr . , according to Matthiessen's standard , 10.35 / may be calculated by the following simple formula : R = d2 R being the resistance in international ohms , the length ...
Сторінка 6
... resistance by merely changing signs ; but this is incorrect algebraically , since it is neces- sary to take the reciprocals of both members of the equation . this is done the following formula is obtained : — RR ( 1.0038701 + ...
... resistance by merely changing signs ; but this is incorrect algebraically , since it is neces- sary to take the reciprocals of both members of the equation . this is done the following formula is obtained : — RR ( 1.0038701 + ...
Сторінка 7
... resistance of a copper conductor at the given temperature t , and R , is its resistance at 0 ° C. Matthiessen found nearly all pure metals to have substantially the same temperature coefficient as copper , the only important exceptions ...
... resistance of a copper conductor at the given temperature t , and R , is its resistance at 0 ° C. Matthiessen found nearly all pure metals to have substantially the same temperature coefficient as copper , the only important exceptions ...
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Electric Lighting: A Practical Exposition of the Art, for the Use of ... Francis Bacon Crocker Попередній перегляд недоступний - 2016 |
Загальні терміни та фрази
alternating current amperes apparatus arc lamps armature arrangement bulb bus bars cable candle-power capacity carbon cent circular mils conductors conduit connected constant current constant potential copper loss core cross-arm cross-section cut-out device diameter difference direct current distribution drop dynamo effect efficiency electric lighting electrical conductors employed energy equal fact feeders feeding-points filament flow frequency full load fuse globe ground heat hence incandescent lamps inch inclosed arc increase inductance insulation iron joint latter length less machines magnetic maximum mechanical metal meter method motor number of lamps ohms one-half open arc operation ordinary parallel phase pipe placed pole polyphase porcelain practically pressure primary produced reactance regulation represented in Fig resistance rheostat rotary rotary converters secondary circuit shown in Fig shunt side single-phase socket supplied switch temperature terminal three-phase three-wire system tion transformers tube two-phase two-wire two-wire circuit usually voltage volts wattmeter watts winding
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Сторінка 460 - The lower limit is specified for rubber-covered wires to prevent gradual deterioration of the high insulations by the heat of the wires, but not from fear of igniting the insulation. The question of drop is not taken into consideration in the above tables.
Сторінка 11 - W, we find that the most economical area of conductor is that for which the annual cost of energy wasted is equal to the annual interest on that portion of the capital outlay which can be considered to be proportional to the weight of metal used. Professor George Forbes, in his Cantor Lecture, on " The Distribution of Electricity...
Сторінка 459 - Must be so placed in wet places that an air space will be left between conductors and pipes in crossing, and the former must be run in such a way that they cannot come in contact with the pipe accidentally. Wires should be run over, rather than under, pipes upon which moisture is likely to gather or which, by leaking, might cause trouble on a circuit.