Setting the pump mode switch to either the A LEAD or
two major categories: (1) fuel oil service control and
B LEAD position sets up the automatic control circuits,
monitoring, and (2) GTM control and monitoring.
allowing the operator to select a lead pump and a standby
Together they function to deliver fuel oil at the proper
pump. From this point, pump control becomes a
pressure and temperature to the individual propulsion
function of header pressure and time.
gas turbines. In the following paragraphs, we will
describe the monitoring and control functions available
GTE FUEL OIL SERVICE.-- For gas turbine
at the PACC for these two categories. Let's first talk
engine (GTE) fuel oil monitoring and control, the
about those for the fuel oil service.
following five functions are available at the PACC:
FUEL OIL SERVICE.-- For fuel oil service
1. Supply temperature monitoring
monitoring and control, the following nine functions are
2. Fuel purge control
available at the PACC:
3. Fuel filter monitoring
1. Fuel oil service tanks A/B temperature
monitoring
4. Main fuel valves control and monitoring
2. Fuel oil service tank suction and recirculating
5. Emergency trip fuel valve control
valves control and monitoring
The primary function of the GTE fuel oil controls
3. Fuel oil service booster pump A and B control
available at the PACC is to control the GTE fuel
and monitoring
shutdown valves and the emergency trip valves. Some
controls are also provided for fuel purging. By closing
4. Prefilter differential pressure monitoring
either of the two main fuel valves, the operator can
(CG-47 class only)
prevent fuel from flowing to the engine fuel manifold.
5. Header pressure and temperature monitoring
The operator's control of these valves, however,
depends on whether the GTE control mode is manual,
6. Heater temperature monitoring
manual initiate, or auto initiate. With the GTE in the
7. Coalescer filter monitoring
manual control mode, the operator can use the
push-button indicator on the PACC to generate main
8. Leak detection tank monitoring
fuel valve control signals to the freestanding electronics
9. Suction strainer differential pressure monitoring
enclosure (FSEE). With the GTE in either the manual
For all nine functions, monitoring is continuously
initiate or auto initiate control mode, the fuel valve
available at both the PACC and the propulsion local
control signals are automatically generated by the
control console (PLCC), but control is available only at
start/stop sequence control logic.
one console at a time.
The other GTE fuel oil controls at the PACC are
At the PACC, control of the fuel oil service system
related to fuel purging operations. A common condition
consists of remote manual control of the suction and
requiring fuel purging is when an engine has been shut
recirculating valves in the two service tanks and remote
down for over 15 days. The fuel will likely have to be
automatic or manual control of the two fuel oil service
purged before the engine is started. This can be done by
pumps. For valve control, the PACC sends open or close
motoring the GTE with the fuel purge valve open. At the
commands to the valve motor controllers. Because both
PACC, the operator opens the fuel purge valve by
valves in a service tank must be in the same state (either
depressing the FUEL PURGE ON push button. This
open or closed) to operate properly, the PACC can send
allows the fuel oil to flow through the engine fuel lines
these commands simultaneously to both the suction and
and into the leak detection tank. In fact, the only way the
the recirculating valves. For service tank control,
fuel valve can open is if an operator pushes the FUEL
separate control switches at the PACC allow the
PURGE ON push button at either the PACC or PLCC.
operator to control each service tank independently. At
Now that we have described the fuel oil service
the PACC, service tank monitoring consists of tank
controls located at the PACC, let's talk about the controls
temperature high and low alarms.
for the lube oil system.
From the PACC, the operator can operate the two
Lube Oil System
fuel oil service pumps in either the manual or automatic
Each main engine room (MER) has its own separate
control mode. By setting the pump mode switch to
MANUAL, the operator can control each of the pumps
and independent lube oil system that can be monitored
individually by using the push buttons on the PACC.
and controlled from the PACC. Monitoring is available
3-3
