propulsion fuel controls deliver fuel oil at the proper
controlled by the computer program function. This
pressure and temperature to each GTE. The fuel oil
program controls the fuel pumps with respect to fuel oil
header pressure and time.
service system may also be operated locally.
The following fuel oil service system control and
T h e following propulsion fuel control and
monitoring functions are available at the PACC:
monitoring functions are available at the PACC:
1. Fuel oil service tank level monitoring
1. GTE fuel oil manifold pressure monitoring
2. Fuel oil service tank suction and return valves
2. GTE fuel oil valve control and monitoring
control and monitoring
3. GTE fuel oil purge control and monitoring
3. Fuel oil service pumps A and B control and
4 . GTM fuel oil filter differential pressure
monitoring
monitoring
4. Fuel oil service heater temperature monitoring
The propulsion fuel oil controls available at the
5. Prefilter differential pressure monitoring
PACC are limited to opening and closing the module
fuel inlet valve and fuel purging. Alarm and status
6. Filter/separator differential pressure monitoring
indicators are also located at the PACC.
Monitoring functions are available at the PACC and the
One solenoid-operated module fuel valve is located
SCU continuously, but control is available only at one
external to the module, in the fuel oil supply piping near
console at a time.
each GTE. The valve is electrically energized closed and
PACC control of the fuel oil service system consists
de-energized open. The valve isolates the module fuel
of remote manual control of the suction and return
oil system from the fuel oil service system. The module
valves associated with the two service tanks. The PACC
f u e l oil inlet valve is controlled by push-button
also has automatic or remote manual control of the two
indicators on the PACC. Separate controls are provided
fuel oil service pumps.
for each GTE. Depressing the MODULE VALVE
CLOSE push button energizes the valve and prevents
The fuel oil suction and return valves computer
fuel flow to the GTE regardless of operating status. If
program function allows the operator to open or close
the MODULE VALVE CLOSE pushbutton is depressed
both service tank valves simultaneously. Separate
when a GTE is ON LINE, ON, or in a cooldown, an
control push buttons are provided to operate each
automatic shutdown occurs.
service tank valve pair independent of the other service
tank valve pair. The computer simultaneously sends the
Fuel purging is an operator-initiated function that
selected (open or close) command to both of the valve
allows the GTE fuel manifold to be drained of cold or
motor controllers associated with a single service tank.
contaminated fuel oil before starting. Purge control is
T h e PACC controls all four valves through their
available for each GTE through PURGE ON and
respective SCU computers.
PURGE OFF push-button indicators at the PACC. A fuel
oil purge is started by the operator from the PACC when
The PACC operates both A and B fuel oil service
PURGE ON is depressed. This action energizes (opens)
p u m p s automatically when their respective motor
the solenoid-operated purge valve in the GTE. The
controllers are aligned for remote operation. The
operator depresses PURGE OFF to close the valve when
push-button indicators at the PACC allow manual
fuel temperature and purity are satisfactory. The purge
control computer program function for the fuel oil
valve's position is indicated by limit switches that
service pumps. The operator may depress the OFF,
control the PURGE ON and PURGE OFF indicators at
LOW SPEED, or HIGH SPEED pushbutton whenever
the PACC. A status message is also shown on the PDU.
a service pump motor controller is in remote. However,
the computer program function will override operator
Lube Oil System
LOW SPEED and HIGH SPEED push-button inputs if
they are contrary to the automatic mode logic of the
c o m p u t e r program function. The operator may
Each MER contains an independent lube oil system
command the operating fuel oil service pumps OFF at
that is controlled and monitored from the PACC.
any time. When a fuel oil service pump is in the OFF
Monitoring is available continuously at both consoles,
state, the automatic mode of the computer program
but control is available at only one of the consoles at a
function is inhibited for that pump. In the automatic
time. The PACC controls the lubricating oil service
mode, after a fuel oil service pump is started, it is
system pressure through the computer program function
3-21
