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

by N. Hawkins

Accordingly before closing main switch B, it is necessary that

1. The frequencies of both machines be the same;
2. The machines must be in synchronism;
3. The voltages must be the same.

Ques. How are the frequencies made the same?

Ans. By speeding up the alternator to be cut in, or change the speed of both until frequency of both machines is the same.

Fig. 2,844.—Diagram of connections of General Electric automatic voltage regulator for several alternators running in parallel with exciters in parallel.

Ques. How are the alternators synchronized or brought in phase?

Ans. The synchronism of the alternators is determined by employing some form of synchronizer, as by the single lamp method of [fig. 2,843], or the two lamp method of [fig. 2,845].

Ques. In synchronizing by the one lamp method, when should the incoming machine be thrown in?