Split-phase motor

Split-Phase Motor. A split-phase motor is a single-phase induction motor equipped with an auxiliary winding, displaced in magnetic position from, and connected in parallel with, the main winding. Note Unless otherwise specified, the auxiliary circuit is assumed to be opened when the motor has attained a predetermined speed. The term split-phase motor, used without qualification, described a motor to be used without impedance other than that offered by the motor windings themselves, other types being separately defined. 

Resistance-Start Motor. A resistance-start motor is a form of split-phase motor having a resistance connected in series with the auxiliary w inding. The auxiliary circuit is opened when the motor has attained a predetermined speed. 

A cage rotor is used on single-phase a.c. motors, the turning force being produced in the way described previously for three-phase induction motors and shown in Fig. 2.49. Because both windings carry currents which are out of phase with each other, the motor is known as a split-phase motor. The phase... 

Figure 2.52 Circuit diagram of (a) capacitor split-phase motors, and (b) resistance split-phase motors.

Split-phase motors are constant speed machines with a low starting torque and are used on light loads such as fans, pumps, refrigerators and washing machines. Reversal of rotation may be achieved by reversing the connections to the start or run windings, but not both. 

Capacitor-Start Motors. Capacitor-start motors are similar to split-phase motors except that a capacitor is placed in series with the start winding to produce greater starting and accelerating torque (Fig. 5.104). After the start winding is removed from the circuit by a centrifugal or electronic switch, performance is identical to that of split-phase motors. 

FIGURE 5.103 Schematic diagram and speed vs. torque diagram—ac split-phase motor. 

Motor J hp, split-phase induction, 60-cycle, 110-volt, a-c, General Electric explosion-proof motor... 

Split-phase Repulsion-stait induction CqKidnnr-stait r- R ulsion-induction Cq>acitor-motor... 

This method can be used to split w/o-emulsions, to separate the smallest water droplets from motor oil, to clear a turbid organic phase after solvent extraction (containing water) and crude oil dewatering, etc. 

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