Cyclopedia of applied electricity : a general reference work on direct-current generators and motors, storage batteries, electrochemistry, welding, electric wiring, meters, electric lighting, electric railways, power stations, switchboards, power transmission, alternating-current machinery, telegraphy, etc. . Fi(r. 159. 3000-Ampere, 3-Phase, Electrically-Operated Oil Circuit Breaker—^1 Pole En-closed; 1 Pole, Door Removed and Tank inPlace; 1 Pole, Door and Tank Removed rests above a small solenoid shown at the left. This coil carries thecurrent of the circuit to be protected. If the current be
Cyclopedia of applied electricity : a general reference work on direct-current generators and motors, storage batteries, electrochemistry, welding, electric wiring, meters, electric lighting, electric railways, power stations, switchboards, power transmission, alternating-current machinery, telegraphy, etc. . Fi(r. 159. 3000-Ampere, 3-Phase, Electrically-Operated Oil Circuit Breaker—^1 Pole En-closed; 1 Pole, Door Removed and Tank inPlace; 1 Pole, Door and Tank Removed rests above a small solenoid shown at the left. This coil carries thecurrent of the circuit to be protected. If the current becomes exces-sive the core within the coil is attracted and the toggle joint is pushedout of its stable position. The switch then immediately opens underthe action of gravity. Fig. 161 shows a number of these switches in the power houseof the Brooklyn Rapid Transit Company. 280 ELECTRIC RAILWAYS 183 COST DETAILS OF POWER PLANTS The function of a power plant is to generate electrical energyat a minimum total cost per kw. hour. The cost may be dividedinto two parts: (a) operation (labor, fuel, sundry); (b) interest,depreciation, maintenance, insurance, Fig. 160. Side View of Fig. 159 ShowingContact Mechanism There is a tendency on the part of beginners to judge the costof producing energy on the basis of operating expenses, but this isbut a part of the total cost. The second part, sometimes called theburden or fixed charges, may be nearly as great, in some in-stances, as the operating costs. The burden is a very variable quantityas it depends upon cost of real estate and other items which differwidely in different communities. Moreover it is difficult to assign 281 184 ELECTRIC RAILWAYS proper values to depreciation. One cannot tell how long an engineor generator will last nor how soon a new type will be developedwhich will require the discarding of the old equipment. : -?:_ 4HPi ??M ^mm ?g^..^^-;; b -^? \ i 1 p=.^.:.. m/m. i 1 ^.:« m ^^^^^H ^v i\.*i*» \ S ^•?< ^^
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Keywords: ., bookauthoramericantechnicalsoci, bookcentury1900, bookdecade1910
