Setting the start switch to high speed causes steps 1
to 5 above to be repeated. This is followed by the
sequence of events listed in table 6-6.
Table 6-6.--Operation of High-Speed Circuit
Figure 6-16.--Reversing ac controller.
Table 6-7.--Forward Operation of a Reversing AC Controller
REVERSING CONTROLLERS
Certain applications call for the ability to reverse the
direction of rotation of installed motors aboard ship.
Whether the motor is ac or dc, the method used to
reverse the direction of rotation is to change the
connections of the motor to the line. Motor controller
controllers make this a quick, simple process.
AC Motors
The rotation of a three-phase induction motor is
reversed by interchanging any two of the three leads to
the motor. The connections for an ac reversing
controller are shown in figure 6-16. The stop, reverse,
and forward push-button controls are all momentary
contact switches. Note the connections to the reverse
and forward switch contacts. (Their contacts close or
If either the stop button or the reverse button is
open momentarily, then return to their original closed or
pressed, the circuit to the F contactor coil is broken, and
opened condition.)
the coil releases and opens line contacts F1, F2, and F3,
The operation of the reversing ac motor controller
and maintaining contact F4.
in the forward position is shown in table 6-7. After the
forward push button is pressed:
6-11
