Figure 3-3.-Emergency and ship's service distribution system interconnections.

The emergency switchboard is connected by

CASUALTY POWER DISTRIBUTION

SYSTEM

feeders (fig. 3-3) to at least one and usually to two

different ship's service switchboards. One of these

A casualty power distribution system is installed

ship's service switchboards is the preferred (normal)

on certain types of ships to provide the means for

source of ship's service power for the emergency

making temporary electrical connections if the

switchboard, and the other is the alternate source. The

permanently installed ship's service and emergency

emergency switchboard and the distribution system

distribution systems cables are damaged. The system

are normally energized from the normal source of

is limited to those facilities that are necessary to keep

ship's service power. If this source of power should

the ship afloat and to permit the ship to get out of a

fail, bus transfer equipment automatically transfers

danger area. The system also supplies a limited

the emergency switchboard to the alternate source of

amount of power to armament and directors to protect

the ship's service power. If both the normal and

the ship when it is in a damaged condition.

alternate sources of power fail, the emergency

If the ship's service and emergency circuits fail,

generator will start automatically within 10 seconds

temporary circuits can be rigged. Also, the casualty

and the emergency switchboard will automatically

power distribution system can be used to supply power

transfer to the emergency generator.

to vital auxiliaries if any of the ship's service or

emergency generators can be operated.

The emergency power distribution system is 450

volts, 3 phase, 60 Hz with transformer banks at the

C o m p o n e n t parts of the casualty power

emergency distribution switchboards to provide

distribution system include permanent and portable

120-volt, 3-phase power for the emergency lighting

cables, bulkhead and switchboard terminals, risers,

and portable switches.

system.

Figure 3-3.-Emergency and ship's service distribution system interconnections.

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