Hawkins Electrical Guide v. 05 (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

Ans. In this method of grouping, the middle points of each of the two phases are united to a common junction M, and the four ends are brought out to four terminals a, a', b, b', as shown in fig. 1,544, or in the case of revolving armatures, to four slip rings.

Fig. 1,544.—Diagram of two phase star grouping.

Ques. What does this arrangement give?

Ans. It is practically equivalent to a four phase system.

Fig. 1,545.—Diagram of two phase mesh grouping.

Ques. How is the two phase mesh connection arranged?

Ans. In this style of grouping, the two phases are divided into two parts, and the four parts are connected up in cyclic order, the end of one to the beginning of the next, so as to form a square, the four corners of which are connected to the four terminals a, b, a', b', as shown in fig. 1,545, or in the case of revolving armatures, to four slip rings.

Ques. Describe a three phase star connection?