PROPULSION FUEL SYSTEM.-- The following
FUEL SERVICE SYSTEM.-- The following six
four functions are available at the PACC for propulsion
monitoring and control functions of the fuel service
fuel monitoring and control:
system are available at the PACC:
1. GTE fuel manifold pressure monitoring
1. Fuel service tank level monitoring
2. GTE fuel valve controls and monitoring
2. Fuel service tank suction and return valves
control and monitoring
3. GTE fuel purge control and monitoring
3. Fuel service pumps A and B control and
4. GTM fuel filter differential pressure monitoring
monitoring
The propulsion fuel controls available at the PACC
4. Fuel service heater temperature monitoring
are limited to opening and closing the module fuel inlet
valve and fuel purging. Alarm and status indicators are
5. Prefilter differential pressure monitoring
also located at the PACC.
6. Filter/separator differential pressure monitoring
The one solenoid-operated module fuel valve
PACC control of the fuel service system consists of
external to the module is located in the fuel supply
remote manual control of the suction and return valves
piping near each GTE. This valve isolates the module
associated with the two service tanks. The PACC also
fuel system from the fuel service system. Push-button
has automatic or remote manual control of the two fuel
indicators on the PACC allow the operator to control the
service pumps.
valve. From the PACC, the operator either can
electrically energize the valve closed or de-energize it
The computer program for the fuel suction and
open. The operator has separate controls for each GTE.
return valves allows the operator to open or close both
By depressing the MODULE VALVE CLOSE push
service tank valves simultaneously. Separate control
button, the operator energizes the valve. This prevents
push buttons are available so the operator can operate
fuel flow to the GTE regardless of its operating status.
the pair of valves in one service tank independently of
If the operator should depress the MODULE VALVE
the pair of valves in the other service tank. The computer
CLOSE push button while a GTE is either ON LINE,
simultaneously sends the selected (open or close)
ON, or in a cool down, an automatic shutdown recurs.
command to both of the valve motor controllers
At the PACC, the operator can initiate the fuel
associated with a single service tank. The PACC
purging function. The fuel purging function allows the
controls all four valves through their respective SCU
operator to drain the GTE manifold of any cold or
computers.
contaminated fuel before starting. Purge control is
The PACC operates the fuel service pumps
available for each GTE through the PURGE ON and
automatically when their respective motor controllers
PURGE OFF push-button indicators at the PACC. The
are aligned for remote operation. The push-button
operator starts a fuel purge by depressing the PURGE
ON push button. This action energizes (opens) the
indicators at the PACC allow the operator to assume
solenoid-operated purge valve in the GTE. The operator
manual control of the computer function program for the
depresses the PURGE OFF push button to de-energize
fuel service pumps. The operator can depress the OFF,
(close) the valve when fuel temperature and purity are
LOW SPEED, or HIGH SPEED push button whenever
satisfactory. The position of the purge valve is indicated
the service pump motor controller is in remote.
by limit switches that control the PURGE ON and
However, the computer program function will override
PURGE OFF indicators at the PACC. A status message
operator LOW SPEED and HIGH SPEED push-button
is also shown on the plasma display unit (PDU). Now
inputs if they are contrary to the automatic mode logic
let's move onto the lube oil system.
of the computer program function. The operator may
command the operating fuel service pumps OFF at any
Lube Oil System
time. When a fuel service pump is in the OFF state, the
automatic mode of the computer program function is
Each MER contains an independent lube oil system
inhibited for that pump. If the PACC is in the automatic
that is controlled and monitored from the PACC.
mode before a fuel service pump is started, the operation
Monitoring is available continuously at both consoles,
of that pump is controlled by the computer function
but control is available at only one of the consoles at a
program. The computer program controls the fuel
time. At the PACC, the operator can control the lube oil
pumps with respect to fuel header pressure and time.
service system pressure through the computer program
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