Ques. How is a three phase mesh connection arranged?
Ans. The three circuits are connected up together in the form of a triangle, the three corners are connected to the three terminals, a, b, c, as shown in fig. 1,549, or in the case of revolving armatures to three slip rings.
Fig. 1,549.—Diagram of three phase mesh grouping, commonly called delta grouping owing to its resemblance to the Greek letter Δ. The voltage at the terminals is equal to the voltage in one phase, and the current in each line is equal to the vector sum of the currents in two phases, that is, it is equal to √3 multiplied by the current in one phase.
Ques. What other name is given to this style of connection, and why?
Ans. It is commonly called a delta grouping on account of the resemblance of its diagrammatic representation to the Greek letter Δ.
Fig. 1,550.—Three phase winding with short coils. The use of short coils as here shown, in which the coil breadth = ⅔ pole pitch, avoids the necessity of overlapping.