Motor Terminal Identification

By 25 July 2017

Usually, the motor terminal connection diagram is given on the motor. For a three-phase motor, three winding end connections are shown – U1 and U2, V1 and V2, and W1 and W2.

Motor terminals and connection diagrams for Auto transformer or DOL starting with three- or six- leads connection are shown in Figure 4.13(a).

Terminal connection diagram
DOL or autotransformer starting with three or six leads. Number of leads connection

Motor terminals and connection diagrams for star–delta starting with six-leads connection is shown in Figure 4.13(b).

Similarly, for a DC motor, field connections are indicated as F1 and F2 while armature winding is shown as A1 and A2. If the DC motor is of a series-type or a compound type, then the series winding leads are shown as S1 and S2.