When the PUSH TO SET FULL SCALE push
provides meter calibration, starts hazard alarms, and
button is depressed, a 20-mA signal is routed from the
provides alarm point adjustment. It also gives fault
meter circuit board to the meter. You can adjust frill scale
condition indication.
by using the mechanical full scale adjust screw on the
TEMPERATURE MONITORING. The final
meter.
area that should be given attention is the temperature
When testing and performing maintenance on the
monitoring circuits. A typical temperature monitoring
FSCC, always follow the applicable electrical safety
circuit is shown in figure 5-36. Temperature of the fuel
precautions. Use common sense when troubleshooting
oil discharge from the two fuel oil transfer heaters is
the console. It is not good practice to test, troubleshoot,
monitored by this system. This temperature is displayed
o r repair the console circuits while refueling or
at the FSCC by a vertical meter. The meter circuitry is
transferring operations are in progress. This is because
located in the fuel oil local control panels.
the chance of damaging equipment or spilling fuel is
increased during maintenance procedures.
Temperature Sensors. The temperature for the
fuel oil is sensed by a resistance temperature detector
( R T D ) . Associated with each RTD is a signal
PROPULSION AND AUXILIARY CONTROL
conditioner. It uses system 24 volts dc to regulate a 4-
CONSOLE/PROPULSION CONTROL
to 20-mA output at a value proportional to the RTD
CONSOLE
Temperature Monitoring Circuits. T h e
T h e propulsion and auxiliary control console
monitoring circuit for fuel oil heater No. 1 is located in
(PACC) is located in the CCS of DD-963, DDG-993,
fuel oil transfer local panel No. 1. The circuit for fuel oil
DDG-51, and CG-47 class ships. On FFG-7 class ships,
heater No. 2 is located in local panel No. 2. Each circuit
this console is called the propulsion control console
(PCC) and is also located in the CCS. These consoles
has a remote display at the FSCC.
provide operator control and monitoring of the ship's
S i n c e the temperature signal from the signal
main propulsion system. Ships that have the PACC also
conditioner is at a 4- to 20-mA level, it is routed through
have the capability of monitoring and controlling some
the PUSH TO SET FULL SCALE switch to the panel
of the auxiliary systems. The PACC and PCC are the
meters. A mode switch allows selection of LOCAL AND
most carefully monitored consoles while the ship is
R E M O T E or LOCAL ONLY displays. The meter
underway. Therefore, improper operation of these
current return is through a fixed resistor to -5 volts.
consoles is immediately noticed. As a GSE,
Figure 5-36.--Typical temperature monitoring circuit.
5-47
