Figure 3-19.-Bus the connections on 400-Hz ships service system.
(STC 1 thru STC 4). Each is rated at 150 KW at 0.8
power factor (fig. 3-20) and distributed to 400 Hz loads
through two distribution switchboards, designated 1SF
Both distribution switchboards provide for
centralized distribution of 450-volt, three-phase,
400-Hz power. Each switchboard is also capable of
controlling and monitoring converter input, converter
output, and bus tie circuit breakers.
Damage to ships service and emergency
distribution systems in wartime led to the development
of the casualty power system. This system provides the
means for making temporary connections to vital
circuits and equipment. The casualty power distribution
system is limited to those facilitues necessary to keep the
ship afloat and permit it to get out of the danger area. It
also provides a limited amount of armament, such as
weapons systems and their directors.
Optimum continuity of service is ensured in ships
provided with ships service, emergency, and casualty
power distribution systems. If one generating plant
should fail, a remote switchboard can be connected by
the bus tie to supply power from the generator or
generators that have not failed
If a circuit or switchboard fails, the vital loads can
be transferred to an alternate feeder and source of ships
Figure 3-20.-400-Hz electric power distribution system.