Abstract :
There follows a list of some of the attendant circumstances and of the advantages which may be gained by the use of the project: 1. Thoroughly reliable power capacitors now are manufactured in great quantities by many firms. 2. Cost is much lower than in 1922. 3. By simple constructions embodying the external-pressure principles by means of which Hochstadter has demonstrated that the service insulation strength of underground high-voltage cables can be doubled for a given insulation thickness, the per-kva cost of power capacitors readily may be decreased much further. 4. By the use of power capacitors as a simple adjunct the power factor and efficiency of an induction motor may be considerably improved for all loads, light and heavy, and the stalling load may be much increased. Throughout a considerable range of load, system economies associated with a leading current will be obtained. 5. Higher-temperature service operation now is recommended, and the rating of the present highly-developed, low-temperature, induction motors may be increased by 33 per cent, without requiring any delays, since no re-designing is involved. There is required merely the substitution of the high heat-resisting insulation now available. 6. The project will permit of the conservation of considerable quantities of critical materials as the result of decreasing by 25 per cent, the per-horsepower weight of the motors. The recommendations made in this paper (and the means proposed) for increasing by 33 per cent the present service rating of general-purpose induction motors is more conservative than many will realize.
