Eaton Power Xpert PXM 4000, Руководство пользователя и инструкция по установке

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IM02601004E
Page 183
12 Glossary
PFD
See, “Power factor”, Displacement. Also known as “True
Power Factor”.
Phasor Diagram
A diagram showing the relationships of as many of the follow-
ing phasor quantities as are neces-sary: armature current,
armature voltages, the direct and quadrature axes, armature
flux linkages due to armature and field winding currents, mag -
netomotive forces due to armature and field winding currents,
and the various components of air-gap flux.
PT (Potential Transformer)
An instrument transformer that is intended to have its primary
winding connected in shunt with a power-supply circuit, the
voltage of which is to be measured or controlled.
Power Factor
A ratio of fundamental (50/60Hz) active power to apparent
power (Fundamental watts to Funda-mental VA).
Power Factor, Apparent
The ratio of the active power of the total rms, in watts, to the
apparent power of the total rms, in volt-amperes. This is also
know as True Power Factor.
Power Factor, Displacement
The ratio of the active power of the fundamental wave, in
watts, to the apparent power of the fundamental wave, in
volt-amperes.
Power Quality
The concept of powering and grounding electronic equipment
in a manner that is suitable to the operation of the equipment
and compatible with the premise wiring system and other
connected equipment.
Pulse Initiator
Any device, mechanical or electrical, used with a meter to
initiate pulses, the number of which are proportional to the
quantity being measured. It may include an external amplifier
or auxiliary relay or both.
Reactive Power
For sinusoidal quantities in a two-wire circuit, reactive power
is the product of the voltage, the current, and the sine of the
phase angle between them. For nonsinusoidal quantities,
it is the sum of all harmonic components, each determined
as above. In a polyphase circuit, it is the sum of the reactive
powers of the individual phases.
RJ-11
A six-pin modular telephone plug. Also called a permissive
connection, an RJ-11 plug is generally used on two-wire
circuits, but can be used on four-wire circuits.
RJ-45
An eight-pin modular telephone plug. Also called a program-
mable connection, an RJ-45 plug is generally used on four-
wire circuits, but can be used on eight-wire circuits such as
Ethernet.
rms (root mean squared)
The effective value, or the value associated with joule heat-
ing, of a periodic electromagnetic wave. The rms value is
obtained by taking the square root of the mean of the squared
value of a function.
RS-232
An EIA standard for asynchronous serial data communica-
tions between terminal devices, such as printers, computers
and communications equipment, such as modems. This stan-
dard defines a 25-pin connector and certain signal character -
istics for interfacing computer equip-ment.
Sag
A decrease in rms voltage at the power frequency for dura-
tions of 0.5 cycle to 1 minute. A sag lasting longer than one
minute is typically called undervoltage.
Swell
An increase in rms voltage at the power fre-quency for dura-
tions from 0.5 cycles to 1 minute. A swell lasting longer than
one minute is typically called overvoltage.
TDD (Total Demand Distortion)
Within the PowerXpert this is the ratio express as a precent of
the rms value of the ac signal after rfundamental component
is removed and interharmonic components are ignored, to the
rated current (CT primary).
%TDD = 100 X CT Primary
(
Σ
) /
85
Cn
2
n=2
1/2