Chapter 1 Manual Bus Transfer, Motor Controllers, and Frequency Regulators

CHAPTER 1

M A N U A L BUS TRANSFERS, MOTOR

C O N T R O L L E R S , AND FREQUENCY REGULATORS

CHAPTER LEARNING OBJECTIVES

Upon completing this chapter, you should be able to do the following:

Describe the procedures to use when performing

Describe the troubleshooting and maintenance

procedures for manual bus transfer (MBT)

corrective maintenance on motor controllers.

switches.

D e s c r i b e the principles of operation of

Identify the different types of electric controllers.

frequency regulators.

Describe the principles of operation of various

Identify the components of motor generators and

types of motor controllers.

their principles of operation.

Describe the procedures for troubleshooting

Describe the procedures for troubleshooting and

motor controllers.

p e r f o r m i n g corrective maintenance on

frequency regulators.

normal power to ship's emergency power, the locking

This chapter discusses the troubleshooting and

maintenance procedures for manual bus transfers

bar must be manually loosened and moved before the

(MBTs), motor controllers, and frequency regulators. To

positions of the switches can be changed. Trouble-

troubleshoot and maintain these components, you need

shooting should be done according to the technical

to have an understanding of the characteristics, uses, and

manual associated with the equipment. Maintenance of

operating principles of the components. Because

the MBT switch should be done according to the

interior communications and weapons systems aboard

modern Navy ships require closely regulated electric

applicable PMS cards.

power for proper operation, you also need to have an

understanding of closely regulated power supplies to

troubleshoot and maintain frequency regulators.

MOTOR CONTROLLERS

Because equipage in special power applications aboard

ship is so diverse, little is said about troubleshooting or

Controllers are commonly used for starting large

maintenance of MBT switches and frequency regula-

motors aboard ship to reduce the amount of current they

tors. In studying this chapter, you should remember to

require when started. The starting current of huge

refer to the manufacturer's technical manual when

motors is usually several times higher than the running

troubleshooting the equipment and to the applicable

current. If controllers are not used for starting, motors

maintenance requirement card (MRC) for maintenance

requirements.

and the equipment they drive may be damaged, or the

operation of other equipment in the same distribution

MANUAL BUS TRANSFER SWITCHES

system may be affected adversely. By definition, a

motor controller is a device (or set of devices) that serves

MBT switches are commonly used for nonvital

to govern, in some predetermined manner, the operation

equipment aboard ship. They consist of two make or

of the dc or ac motor to which it is connected.

break switches and a locking bar. To transfer from

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