Table 9-1.--Alarm, Safety, and Warning Systems

Table 9-1.--Alarm, Safety, and Warning Systems--Continued

Circuit

Readiness Class

System

Importance

Seawater expansion tank low-level alarm

19TD

20TD

Gasoline drain tank high-level alarm

21TD

Moisture separater drain cooler high-level alarm

24TD

Reactor plant on board discharge tank level alarm

Crossover drains high-level alarm

25TD

29TD

Sonar dome fill tank low-level alarm

30TD

JP-5 fuel drain tank high-level alarm

Train warning system

Whistle operating system

Legend:

V-Vital

SV-Semivital NV-Nonvital.

1-Continuously energized-supply switch color code yellow.

2-Energized when preparing to get underway, while underway, and until the ship is secured-

supply switch color code black.

3-Energized during condition watches-supply switch color code red.

4-Energized only when required-supply switch color code white.

All electronic type alarm systems formerly designated as circuits CA, FC, FW, G, GD, GJ, GN,

and FP are now classified as a portion of the respective announcing system with which they are

associated.

mercury thermostat functions somewhat like a

the mercury to rise in the tube. When the mercury

reaches the top contact, the resistor will be shunted

thermometer in that the column of mercury rises as

from the circuit, and the current will increase, The

temperature increases. Under normal conditions, a

increase in current will cause a relay contact to close

small amount of direct current flows from one side of

and initiate an alarm.

the line through the resistor, the middle contact, the

mercury, the bottom contact, and back to the other

Mercury thermostats are installed in the overhead

side of the line. An increase in temperature will cause

of magazines, storerooms, paint lockers, and other

Figure 9.1.--Mercury thermostat.

9-5