Figure 7-45.Four 115-volt coil connected in parallel for 230 volts; each coil still receives only 115 volts.
supply. Each coil receives 115 volts. If the four coils
were connected in two parallel sets of coils to a 230-volt
line, as shown in figure 7-45, each coil would still
receive 115 volts. So, regardless of the line voltage, the
coil voltage is the same. This is the principle used in all
dual-voltage machines. Therefore, if four leads are
brought out of a single-phase motor designed for
460/230 or 230/115-volt operation, the motor can be
readily connected for either voltage.
Dual-Voltage Wye Motor
When you are connecting a dual-voltage wye
motor, remember practically all three-phase dual-
Figure 7-46.Terminal markings and connection for a wye-
connected dual-voltage motor.
voltage motors have nine leads brought out of the motor
from the winding. These are marked TI through T9, so
that they may be connected externally for either of the
two voltages. These are standard terminal markings and
are shown in figure 7-46 for wye-connected motors.
HIGH VOLTAGE.to connect for high voltage,
you should connect groups in series, as shown in figure
7-47. Use the following procedure:
1. Connect T6 and T9; twist and wire nut.
2. Connect leads T4 and T7; twist and wire nut.
3. Connect T5 and T8; twist and wire nut.
4. Connect leads TI, T2, and T3 to the three-phase
LOW VOLTAGE.This same motor can be
connected for low voltage. Use the following
Figure 7-47.Two-voltage wye motor windings connected in
serifs for high-voltage operations.