is used to supply compressed air to the GTEs for the
SHIP'S SERVICE POWER UNIT (SSPU).-- T h e
purpose of starting.
SSPU is the main source of electrical power for a
P H M . It consists of a gas turbine engine, a
STATOR.-- The nonrotating part of the magnetic
mechanical gearbox, an ac generator, hydraulic
pumps, and a load compressor.
SUMMARY ALARM.-- An indicator at a console that
SHORT CIRCUIT.-- Also called a short. An abnormal
indicates to an operator that one of several abnormal
connection of relatively low resistance between two
conditions has occurred on a certain piece of
points of a circuit. The result is a flow of excess
equipment.
(often damaging) current between these points.
S W I T C H B O A R D . -- A single large panel or an
assembly of panels on which are mounted the
SIGNAL CONDITIONING ENCLOSURE
s w i t c h e s , circuit breakers, meters, fuses, and
(S/CE).-- Part of the PAMISE and provides the
major input interface between the propulsion plant
terminals essential to the operation of electrical
machinery and the ECSS control consoles. The
equipment.
S/CE accepts inputs from the plant machinery and
TACHOMETER.-- An instrument used to measure the
outputs normalized signals to the ECSS control
speed of rotation of a device.
consoles. Also has alarm detection and alarm output
TEMPERATURE.-- The quantitative measure of the
circuitry. One S/CE is located in each engine room
relative hotness or coldness of an object.
and one is apart of the CISE (located in CCS).
THERMAL ENERGY.-- The potential and kinetic
SILICON CONTROLLED RECTIFIER (SCR).-- A
energy of particles of a body that can be evolved as
four layer PNPN semiconductor device that, when
heat.
in its normal state, blocks a voltage applied in either
direction. The SCR is enabled to conduct in the
THERMOCOUPLE.-- (1) A bimetallic device capable
forward direction when an appropriate signal is
o f producing an emf roughly proportional to
applied to the gate electrode.
temperature differences on its hot and cold junction
ends. (2) A junction of two dissimilar metals that
SOLDERING.-- The joining of metallic surfaces (for
produces a voltage when the junction is heated.
example, electrical contacts) by melting a metal or
T O L E R A N C E . -- The allowable deviation from a
an alloy (usually tin and lead) over them.
specification or standard.
SOLENOID.-- A coil of wire in the form of a long
T R A N S D U C E R . -- (1) A device that converts a
cylinder that resembles a bar magnet. When current
mechanical input signal into an electrical output
flows in the wire, a movable core is drawn into the
signal. (2) Generally, a device that converts energy
coil.
from one form into another, always retaining the
S O L I D STATE.-- (1) Pertaining to circuits and
characteristic amplitude variations of the energy
components using semiconductors. (2) The physics
converted.
of materials in their solid form (for example, diodes
T R A N S F O R M E R . -- A device composed of two or
and transistors).
more coils, linked by magnetic lines of force, used
to step up or step down an ac voltage.
SPLIT PLANT.-- The condition in which only one
engine in an engine room is driving the reduction
TURBINE OVERTEMPERATURE PROTEC-
gear/propulsion shaft.
TION SYSTEM (TOPS) .-- A system used on a CG-
or DD-class ship to protect a surviving generator
S T A R T E R A I R S Y S T E M . -- Takes both hot
from overload if another generator fails.
compressed bleed air from the bleed air collection
and distribution system and cool compressed bleed
TURBINE INLET TEMPERATURE (TIT).-- T h e
air from the masker air system and distributes them
GTGS turbine inlet temperature on the Allison
t o both the GTEs and GTGs for starting and
501-K17. (Known as T5.4 for an LM2500 GTE.)
motoring.
ULTRAVIOLET (UV) DETECTOR.-- A device that
senses the presence of fire in the GTE and GTG
S T A R T I N G AIR COMPRESSOR (SAC).-- T h e
enclosure and generates an electrical signal that is
shaft-driven centrifugal compressor mounted on the
sent to the ECSS, MCS, or PCS.
end of a diesel engine on the FFG-7 class ships. It
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