OHM.-- Symbolized by the Greek letter omega (Ω). The
POWER LEVEL ANGLE (PLA).-- A rotary actuator
mounted on the side of the GTE fuel pump and its
unit of resistance. One ohm is the value of resistance
output shaft lever. It is mechanically connected to
through which a potential difference of 1 volt will
the MFC power lever. The PLA actuator supplies
maintain a current of 1 ampere.
the torque to position the MFC power lever at the
OIL DISTRIBUTION (OD) BOX.-- This box is located
commanded rate.
at the forward end of each MRG assembly. It directs
POWER SUPPLY.-- A unit that supplies electrical
HP oil from the HOPM to the propeller hub through
power to another unit. It changes ac to dc and
t h e shaft bore. The OD box also establishes
maintains a constant voltage output within limits.
propeller pitch by using control oil from the HOPM
to position the valve rod, which extends through the
POWER TURBINE (PT).-- The GTE turbine that
shaft to the hub.
converts the GG exhaust into energy and transmits
OPEN CIRCUIT.-- A circuit that does not provide a
the resulting rotational force via the attached output
complete path for the flow of current.
shaft.
ORIFICE.-- A circular opening in a flow passage that
PRAIRIE AIR SYSTEM.-- This system emits cooled
creates a flow restriction.
bleed air from small holes along the leading edge of
the propeller blades. The resulting air bubbles
PARAMETER.-- A variable, such as temperature,
disturb the thrashing sound so identification of the
pressure, flow rate, voltage, current, or frequency
type of ship through sonar detection becomes
that may be indicated, monitored, checked, or
unreliable.
sensed in any way during operation or testing.
PRESSURE.-- Force per unit of area, usually expressed
PERMANENT MAGNET ALTERNATOR (PMA).--
as psi.
The PMA is mounted on the generator shaft
extension of each GTGS and supplies speed sensing
PRESSURE SWITCH.-- A switch actuated by a change
and power to the electronic governor. The PMA also
in the pressure of a gas or liquid.
supplies initial generator excitation.
PRESSURE TRANSDUCER.-- An instrument that
PHASE.-- (1) The angular relationship between current
converts a static or dynamic pressure input into the
and voltage in ac circuits. (2) The number of
proportionate electrical output.
s e p a r a t e voltage waves in an ac supply (for
example, single-phase and three-phase).
PRIME MOVER.-- (1) The source of motionas a GTE,
(2) the source of mechanical power used to drive a
PHOTOELECTRIC.-- Electricity produced by the
pump or compressor, (3) or the rotor of a generator.
action of light.
PROPELLER.-- A propulsive device consisting of a
PITCH.-- A term applied to the distance a propeller will
boss or hub carrying two or more radial blades.
advance during one revolution.
(Also called a screw.)
PLASMA DISPLAY UNIT (PDU).-- An orange-
PROPULSION AUXILIARY CONTROL CON-
colored backlit display screen mounted in the panel
SOLE (PACC).-- This console is located in the CCS
face of the MCS consoles. Typed data in
and is part of the PAMCE. It contains the electronic
alphanumeric format is printed on the interior
equipment capable of controlling and monitoring
plasma face of the unit. It is used to present
both propulsion plants and auxiliary equipment on
equipment status data to operators for information
a CG-47, DD-963, or DDG-993 class ship. (Also
or action.
known as the PACC on the DDG-51 class ship but
PMS FEEDBACK REPORT.-- A form ships use to
not a part of PAMCE.)
notify the Naval Sea Support Center or the type
commander of matters related to PMS.
PROPULSION AND AUXILIARY MACHINERY
C O N T R O L EQUIPMENT (PAMCE).-- This
POTENTIOMETER.-- A variable resistance unit
equipment is located in the CCS, is part of the
having a rotating contact arm that can be set at any
ECSS, and includes the PACC and PACEE. This
desired point along the resistance element.
e q u i p m e n t provides centralized control and
POWER.-- The rate at which work is done. Units of
monitoring of both main propulsion plants and
power are the watt, the joule, and the kilowatt.
auxiliary machinery on a CG- or DD-class ship.
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