POTENTIOMETER-- A variable resistance
POWER TURBINE SPEED (Np t ) --The
speed sensed by magnetic pickups in the GTE
unit having a rotating contact arm that can be set
turbine rear frame.
at any desired point along a resistance element.
POUNDS PER SQUARE INCH (psi)--A
PRAIRIE AIR SYSTEM--This system emits
unit of pressure.
cooled bleed air from small holes along the leading
edges of the propeller blades. The resulting air
POUNDS PER SQUARE INCH ABSOLUTE
bubbles disturb the thrashing sound so identifica-
(psia)-- A unit of pressure.
tion of the type of ship through sonar detection
becomes unreliable.
POUNDS PER SQUARE INCH DIFFER-
ENTIAL (psid)--A unit of pressure. Also known
as delta (Ap) pressure.
PRESSURE-- Pressure is force per unit of
area, usually expressed as psi.
POUNDS PER SQUARE INCH GAUGE
(psig)-- A unit of pressure.
PRESSURE FEED SYSTEM--A system in
which pressure (rather than gravity) is used to
POWER LEVER ANGLE (PLA)--A rotary
maintain flow.
actuator mounted on the side of the GTE fuel
pump and its output shaft lever. It is mechanically
PRIME MOVER--(1) The source of
connected to the MFC power lever. The PLA
motion--as a gas turbine engine. (2) The
actuator supplies the torque to position the MFC
source of mechanical power used to drive
power lever at the commanded rate.
a pump or compressor. (3) The source of
mechanical power used to drive the rotor of
POWER ON RESET--A signal generated by
a generator.
each electronics enclosure when it is energized.
This signal preconditions electronic circuitry in
the control console (whose power is supplied by
PRINTED CIRCUIT BOARD (PCB)--(1)
that electronics enclosure) to a known state for
An electronic assembly mounted on a card,
operational purpose during application of power
using etched conductors. Also called printed
to the console.
wire board (PWB). (2) Devices usually plug-
ged into receptacles that are mounted in
POWER SUPPLY--The module that con-
modules.
verts the 115-volt, 60-hertz incoming power to ac
or dc power at a more suitable voltage level.
PRIORITY-- Order established by relative
importance of the function.
POWER TAKEOFF (PTO)--The drive shaft
between the GTGS gas turbine engine and the
reduction gear. Transfers power from the gas
PROPELLER-- A propulsive device con-
turbine to the reduction gear to drive the
sisting of a boss or hub carrying two or more
radial blades. Also called a SCREW.
POWER TURBINE (PT)--The GTE turbine
PROPULSION AND AUXILIARY CON-
that converts the GG exhaust into energy and
TROL CONSOLE (PACC)--This console is
transmits the resulting rotational force via the
located in CCS and is part of the PAMCE. It
attached output shaft.
contains the electronic equipment capable of
controlling and monitoring both propulsion plants
POWER TURBINE INLET TEMPERA-
and auxiliary equipment on a DD or CG class
TURE (T5.4)--The temperature sensed by
ship.
thermocouples installed in the GTE midframe.
POWER TURBINE INLET TOTAL PRES-
P R O P U L S I O N AND AUXILIARY
CONTROL ELECTRONICS ENCLOSURE
SURE (Pt 5 . 4 ) --The pressure sensed by five total
(PACEE)--This enclosure is located in CCS and
pressure probes located in the GTE turbine mid-
frame and piped to a transducer on the bottom
has the electronics that supply power to the PACC
of the GTM.
on a DD or CG class ship.
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