As shown in the two-speed single winding three phase motor connection diagrams illustrated in figure "B", what is the connection scheme associated with low speed operation? Illustration EL-0118

Correct Answer: Option A — series delta

In a two-speed, single-winding motor (often a Consequent Pole design), the series delta connection is utilized for low-speed operation. This configuration effectively doubles the number of active poles compared to the high-speed connection, thereby reducing the synchronous speed of the motor according to the standard pole-speed relationship.