Hawkins Electrical Guide v. 08 (of 10) / Questions, Answers, & Illustrations, A progressive course of study for engineers, electricians, students and those desiring to acquire a working knowledge of electricity and its applications

THE THOUGHT IS IN THE QUESTION THE INFORMATION IS IN THE ANSWER
QUESTIONS ANSWERS & ILLUSTRATIONS
A PROGRESSIVE COURSE OF STUDY FOR ENGINEERS, ELECTRICIANS, STUDENTS AND THOSE DESIRING TO ACQUIRE A WORKING KNOWLEDGE OF
ELECTRICITY AND ITS APPLICATIONS
A PRACTICAL TREATISE by HAWKINS AND STAFF
THEO AUDEL & CO. 72 FIFTH AVE. NEW YORK .
COPYRIGHTED, 1915, BY THEO. AUDEL & CO., New York.
Printed in the United States.
TABLE OF CONTENTS GUIDE No. 8

The great importance of the wave form in alternating current work is never denied, though it has sometimes been overlooked. The application of large gas engines to the driving of alternators operated in parallel requires an accurate knowledge of the wave form, and a close conformation to a sine wave if parallel operation is to be satisfactory. It is also important that the fluctuations in magnetism of the field poles should be known, especially if solid steel pole faces be used.
If an alternator armature winding be connected in delta, the presence of a third harmonic becomes objectionable, as it gives rise to circulating currents in the winding itself, which increase the heating and lowers the efficiency of the machine.