ALARM, SAFETY, AND WARNING SYSTEMS
Upon completion of this chapter you will be able to do the following:
Explain the purpose of alarm, safety, and warning systems installed on Navy
ldentify the various sensing devices used with alarm, safety, and warning
Identify the various audible and visual devices used with alarm, safety, and
Describe the components and operation of a B-51 alarm panel.
Describe the components and operation of an IC/SM alarm panel.
Briefly describe some of the common troubles of alarm, safety, and warning
systems and their effects on the systems.
Devices are used with alarm, safety, and warning
Alarm, safety, and warning systems are installed
systems to initiate alarms when there is a deviation in
in Navy ships for certain equipment and compart-
normal operation. A sensing device senses the
ments. These systems provide audible and visual
deviation and, in turn, causes a switch or relay contact
signals when abnormal or dangerous conditions
to close and energize the alarm signaling device.
occur. The principal components of the alarm, safety,
Sensing devices include switches, detectors, and
and warning systems are sensing devices, audible and
visual signals, alarm panels, and alarm switchboards.
Circuit designations and classifications of some of the
more common systems are listed in table 9-1.
Switches used with the alarm, safety, and warning
Sources of possible trouble areas in many of the
systems include lever-operated, pressure-operated,
interior communication circuits are components that
mechanical, water, liquid-level, and thermostatic
transmit information and the components that warn of
switches. These switches were discussed in chapter 3
malfunctions. Often, even though the detector and
of this training manual. In addition, the alarm, safety,
repeater parts of a system are aligned, an error is
and warning systems use flow switches, relay
introduced by components that transmit or retransmit
switches, and mercury thermostats.
This chapter discusses some of the devices that
transmit information and warn of malfunctions. When
Flow switches are installed in fluid lines to sense
you complete this chapter, you should have a basic
fluid flow. As the fluid flow rate increases or
understanding of transmission, alarm, and indicating
decreases, the contacts in the flow switch will close
systems, and be prepared to deal with malfunctions in
and initiate an alarm. Flow switches are available in
various sizes to sense a variety of flow rates.