Report of board of engineers on specifications for electric light and power installations of seacost batteries

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1902 edition. Excerpt: ...as to charge, and this without interfering with the operation of any of the lights or motors throughout the installation. The generator can be of a standard commercial type, as special winding for raising the voltage during the charging of the accumulators is not required. The danger of discharging the accumulator through the generator is reduced to a minimum since the counter electromotive force due to the accumulator in parallel is much below the normal voltage of the generator. The wiring and switchboard arrangements and the manipulation of the accumulators are made exceedingly simple. The greatest disadvantage of this method of charging is its low efficiency; but this, while a serious objection in commercial practice, is of secondary importance in fortification work. The capacity of the accumulator should be sufficient to carry the full lighting load for a period, depending on local conditions, of from four to eight hours without reducing the voltage of the battery below 1.9 per cell, measured while discharging at normal rate, and this voltage should be considered a minimum below which the battery should never be discharged except in an emergency. The number of cells for the accumulator in any given case is determined by the voltage of the lighting circuit, and in the general case where 110-volt lamps ai-e used, 58 cells in series will be sufficient. Connections between elements should be so designed that no metals other than lead shall be exposed to the fumes from the accumulator. The insulation of the cells from the earth should be as perfect as possible, and of the latest and most approved method; and the installation and initial charging should be in strict accordance with the instructions and specifications of the makers. Glass jars have...