TEMPERATURE audible and visual alarm. The second
therefore, there is no LOCAL/REMOTE indicator on
detector supplies a signal to an indicator mounted on the
the EPCC for this switchboard.
diesel engine gauge board. A temperature switch is also
located in the diesel engine jacket water outlet piping.
Shore Power Monitoring and Control
The switch energizes a high-temperature alarm on the
The EPCC operator can monitor the seven breakers
local switchboard.
connected to shore power and can use the TRIP lever to
A pressure transducer, located at the discharge of
trip all seven breakers. current up to 3000 amperes from
the jacket water pump, provides a signal to the EPCC
the shore power source can be monitored on a meter at
for demand display readout. The expansion tanks have
the EPCC. Each of the seven breakers can handle 400
both a liquid level gauge and a low level alarm. The low
amperes. The status of each breaker is indicated by
level alarm energizes an audible and visual alarm at the
illumination of its own blue light. The EPCC controls
EPCC when the level drops to 7 1/2 gallons.
the transfer of shore power to ship's power only. The
The EPCC controls the flow of seawater to the
transfer of ship's power to shore power can only be
j a c k e t water system by opening or shutting the
accomplished by the 3SA switchboard.
motor-operated valve leading from the seawater chest.
Engine Fuel Service System
A dual illuminated indicator on the EPCC monitors the
OPEN or SHUT condition of the seawater valve. The
The EPCC provides for remote monitoring of the
discharge of seawater, after it has picked up heat from
SSDG's fuel service system. The EPCC indicates with
the jacket cooler, is routed to the overboard valve. The
alarms when the fuel tank level is beyond the high level
EPCC has controls and monitoring associated with this
of 90 percent of tank capacity or drops below the low
discharge.
level of 20 percent of capacity. Engine fuel discharge
pressure and manifold pressure are monitored by the
SCS
EPCC through the SCS. Engine fuel discharge pressure
is displayed on edgewise meters on the EPCC front
This program module SCS monitors the electric
p a n e l . To avoid transient alarms, the supervisory
plant for failures or degradation of performance. If
provides a 16-second delay on the level indicating
e i t h e r condition o c c u r s , the SCS either initiates
alarms.
corrective action or alerts the operator to take corrective
action. The supervisory control is executed during the
Auxiliary Fuel Service System
allotted 50-millisecond interval of every
200-millisecond program cycle when the supervisory
The EPCC controls the suction valves for each of
control mode switch is in the AUTO position. When
the six auxiliary fuel tanks. The EPCC operator can
executed, this function reads the SHORE POWER
control which tank is used to supply SSDG No. 4 or
indicator, the supervisory control mode, and each SSDG
SSDG No. 1, since they have two tanks. The SSDG No.
control mode. If the electric plant is on shore power or
2 and No. 3 share two day tanks; therefore, the EPCC
the supervisory control mode is off or all SSDGs are in
operator can only open or close these tanks. The EPCC
the local control mode, control is returned to the
operator cannot transfer fuel to the day tanks. This
executive control program. Otherwise, the status of each
transfer is done locally in auxiliary room No. 2.
SSDG is established and a bit pattern is generated to
identify the SSDG status and those SSDGs operating in
Jacket Water System
parallel. Each SSDG status is recorded in a 16-bit
computer word and updated each program cycle. Refer
The jacket water system provides cooling water to
to the appropriate technical manual for a detailed
the jacket of the diesel engine and acts to cool the
discussion on the SCS.
lubricating oil. Each engine is served by its own jacket
water system. The water is circulated through each
ACC
system by a centrifugal pump that is apart of the diesel
engine.
The ACC, shown in figure 3-14, controls and
monitors 15 auxiliary subsystems and interfaces with
Two resistance temperature detectors (RTDs) are
the software program of the EPCC. This interface
provided in the jacket water outlet line from the diesel
provides for demand display readout, alarm monitoring,
engine. One detector provides a signal to the EPCC to
and logging data on the data logger. Controls and
provide continuous display and to actuate a HIGH
3-36
