Abstract :
THERE are four effective materials concerned in turbo-generator operation, namely, the iron for magnetic purposes, the copper in the windings, the insulation encasing the windings and the ventilating air. As the iron and copper have long since been carried to their practical limits, it follows that the major part of recent developments has been in the insulation and the ventilation. In fact, it may be said that the present commercial insulations for such apparatus have been utilized fairly well up to their limits for some years. Therefore, it follows that the more recent growth in large turbo-generator work has been largely along the lines of improved methods of heat dissipation, that is, of improved air circulation.
