Rockwell Automation 1403-DM_LM_MM Powermonitor II Instruction Sheet - Manual (Page 82)

D-2 Glossary
1403-IN001A-US-P
demand interval
Demand charges are based on peak demand over a
utility specified time interval, not on the
instantaneous demand (or connected load) at any
given moment. Typical demand intervals are 15, 20
and 30 minutes.
F
frequency
The number of recurrences of a periodic
phenomenon in a unit of time. In electrical terms,
frequency is specified as so many Hertz (Hz) where
one Hz equals one cycle per second.
H
horsepower (hp)
A unit of power, or the capacity of a mechanism to do
work. It is equivalent to raising 33,000 pounds one
foot in one minute. One horsepower equals 746
watts.
I
impedance
The total opposition (i.e., resistance and reactance) a
circuit offers to the flow of alternating current at a
given frequency. It is measured in ohms.
induction motor
An alternating current motor in which the primary
winding (usually the stator) is connected to the power
source and induces a current into a secondary
(usually the rotor).
inductor
A device consisting of one or more windings with or
without a magnetic core. Motors are largely
inductive.
initiator pulses
Electrical impulses generated by pulse-initiator
mechanisms installed in utility revenue meters. Each
pulse indicates the consumption of a specific number
of watts. These pulses can be used to measure energy
consumption and demand.
L
lagging current
The current flowing in an AC circuit which is mostly
inductive. If a circuit contains only inductance the
current lags the applied voltage by 90 degrees.
Lagging current means lagging power.
leading current
The current flowing in a circuit which is mostly
capacitive. If a circuit contains only capacitance the
current leads the applied voltage by 90 degrees.
Leading current means leading power factor.
load
Any device or circuit consuming power in an
electrical system.
load shedding
The removal of load from the line to limit load and
control demand level.
load restoring
The energization of loads that were previously
removed from the line to limit load and control
demand level.
N
neutral
The conductor chosen as the return path for the
current from the load to the source. It is also a
voltage reference point in a power system.