Electrical Control Circuit Schematic Diagram of Two-Value Capacitor Motor

TWO-VALUE CAPACITOR MOTOR

Figure 1: An autotransformer consisting of a coil of wire wound on a laminated core. The coil is tapped at several points to obtain different voltages

Electrical Control Circuit Schematic Diagram of Permanent Split Capacitor Motor

PERMANENT SPLIT CAPACITOR MOTOR

Figure 1: A permanent-split capacitor-run motor with the capacitor mounted on the motor

Electrical Control Circuit Schematic Diagram of Capacitor Start Motor

Figure 1: Typical capacitor start motor

Standard Terminal Markings of DC (Direct Current) Motors

Standard terminal markings, as developed by NEMA, are given for series, shunt and compound motors in figure 1, figure 2 and figure 3 respectively. These figures all show compensating-field as well as commutating-field windings since they are intended to cover both fractional horsepower and integral horsepower motors. Fractional horsepower motors do not generally use compensating windings and they may not use commutating-field (interpole) windings.

The markings are combinations of letters and arabic numerals, generally, these are as follows:

- Armature - A1, A2
- Control signal lead - C
- Series field - S1, S2
- Shunt field - F1, F2

Reversing DC Motors

Procedure for reversing direct current motors

Direct current motors are reversed by changing the direction of current flow through the armature or through the field. In series motors, the usual procedure is to reverse the current through the armature. Figure 1 shows this method.

All that is necessary is to interchange the leads on the brush holders. Figure 2 shows the series motor reversed by changing the current in the field circuits.