also has eight power supplies located in the power
FUEL SYSTEM CONTROL CONSOLE
supply drawers. Maintenance of power supplies was
The FSCC is located in the CCS of DD-963,
discussed earlier in this chapter.
D D G - 9 9 3 , and CG-47 class ships. This console
TANK LEVEL MONITORING AND ALARM
provides operator control and monitoring of the ship's
G E N E R A T I O N . -- One area of the FSCC that you
fuel storage and transfer system. Maintenance of this
s h o u l d give particular attention is the tank level
console is the responsibility of the GSEs.
monitoring and alarm circuits. Individual tank levels are
displayed by vertical panel meters. The tank level
FSCC Testing
circuits convert analog information from a tank level
transmitter to a meter display. Some of the circuits have
Testing the FSCC is a task you, the GSE, must
a s s o c i a t e d hazard alarms for high- or low-level
perform daily. The daily tests consist of a hazard alarm
conditions.
test, fault alarm test, and lamp test.
Tank Level Transmitters.-- Each level-monitored
You will use the hazard alarm test to make sure the
tank has a level transmitter. A typical transmitter section
hazard alarm circuits are functioning properly. Start the
has a voltage divider resistor network extending the
hazard alarm test by depressing the HAZARD ALARM
length of the section. Magnetic reed switches are tapped
TEST push button on the FSCC. This action will cause
at 1-inch intervals along the resistor network. The reed
each hazard alarm circuit to start a hazard alarm,
switches are sequentially connected through series
consisting of a 4-Hz flashing light and a 4-Hz tone.
resistors to a common conductor. This network is
You will use the fault alarm test to make sure the
enclosed in a stem that is mounted vertically in the tank.
fault alarm circuits are functioning properly. Start the
Afloat with bar magnets rides up and down the stem as
fault alarm test by depressing the FAULT ALARM
the level changes.
TEST push button on the FSCC. This action will cause
Tank Level Monitoring Circuits.-- Refer to the
each fault alarm circuit to start a fault alarm, consisting
typical tank level monitoring circuit shown in figure
of a 1-Hz flashing light and a 1-Hz tone.
5-34. The signal from the level transmitter is sent to a
The last daily test you must perform on the FSCC
level monitoring circuit in the FSCC. This circuit, in
is the lamp test. Start the test by depressing the LAMP
turn, drives the associated panel meter(s) and starts the
TEST push button on the FSCC. This action will cause
visual and audible indications for a hazard alarm. This
all the indicator lights not checked by the alarm tests to
circuit also provides sensor circuit fault indication and
light steadily, allowing you to locate burned out lamps
meter and alarm calibration.
on the console.
PRESSURE MONITORING AND ALARM
You will also test the meters on the FSCC, but not
GENERATION.-- Another important area of the FSCC
daily. In these tests, you must use the calibrate panel on
is the pressure monitoring and alarm generation circuits.
the back of the FSCC. You will usually calibrate these
Pressure is monitored and displayed for the fuel oil
meters before refueling and during PMS. You will use
receiving tanks, transfer pump inlets and discharges, and
the calibrate panel to accomplish calibration of the
purifier inlets and discharges. All but the purifier inlets
storage tank level meters, the receiving tank pressure
have HIGH PRESS hazard alarms. These circuits are all
meters, and the high seawater and fuel overflow alarms.
functionally similar.
Pressure Transducers.-- Pressure transducers are
FSCC Maintenance
supplied with +24 volts dc. They regulate current flow
between this +24 volts and common so that the current
Most of the maintenance required on the FSCC will
remains regulated proportional to the pressure input.
stem from the failure of one of the tests we have just
The current is varied from 4 to 20 milliamps (mA) as
described. If an indicator fails to light or a meter fails to
the pressure changes from the low extremity of its range
respond correctly, you must find the cause of the failure.
to the maximum. Current regulation is accomplished by
Always refer to the manufacturer's technical manual
circuits located within the transducer.
whenever you perform maintenance on the FSCC.
Pressure Monitoring Circuits.-- Study the typical
When you are trying to locate a problem, there are
pressure monitoring circuit shown in figure 5-35. The
several circuits in the FSCC you must investigate. There
pressure signal from the pressure transducer is sent to a
are a total of 32 printed circuit boards (PCBs) used in
monitoring, alarm, and control functions. The FSCC
pressure monitoring circuit in the FSCC. This circuit
5-45
