Figure 3-43.--Bus tie connections on 400-hertz ship's service system.
(STC 1 thru STC 4), each rated at 150 KW at 0.8 power
systems. On some ships 400-hertz power is generated
factor (fig. 3-44) and distributed to 400 Hz loads
by motor-generator sets and distributed via special
through two distribution switchboards, designated 1SF
frequency switchboards (fig. 3-42) to the various
and 2SF.
400-hertz equipment.
Both distribution switchboards provide for
These motor generators supply power to ship's
centralized distribution of 450-volt, three-phase,
service special frequency switchboards. Figure 3-43 is
400-hertz power. Each switchboard is also capable of
a simplified line diagram of the 400-hertz ship's service
controlling and monitoring converter input, converter
bus tie interconnections on an older ship. The circuits
output, and bus tie circuit breakers.
being fed from the 400-hertz ship's service
switchboards are deleted from the figure for simplicity.
CASUALTY POWER DISTRIBUTION
Newer ships get their supply of 400-Hz power
SYSTEM
through the use of 60/400-Hz static converters. The
400-Hz system consists of four MBT's supplying 60 Hz
Damage to ship's service and emergency
power to four 60/400-Hz static frequency converters
distribution systems in wartime led to the development
Figure 3-44.--400Hz electric power distribution system aboard a new DDG.
3-35
