Feeder
A circuit, such as conductors in conduit or a busway
run, which carries a large block of power from the service equipment to a
sub-feeder panel or a branch circuit panel or to some point at which the
block power is broken into smaller circuits.
Ferroresonance
Resonance resulting when the iron core of an inductive
component of an LC circuit is saturated, increasing the inductive reactance
with respect to the capacitance reactance.
Ferroresonant
Transformer
A voltage regulating transformer
which depends on core saturation and output capacitance.
Field
The space containing electric or magnetic
lines of force.
Filter Frequency Range
The frequency range within which the filter operates.
Flashover
Flashing due to high current flowing between two points
of different potential. Usually due to insulation breakdown resulting from
arcing.
Fluctuation
A surge or sag in voltage amplitude, often caused by
load switching or fault clearing.
Flux
The lines of force of a magnetic field.
Forward Transfer
Impedance
The amount of impedance placed between the source and
load with installation of a power conditioner. With no power conditioner,
the full utility power is delivered to the load; even a transformer adds
some opposition to the transfer of power. On transformer based power
conditioners, a high forward transfer impedance limits the amount of inrush
current available to the load.
Frequency
The number of complete cycles per second existing in any
form of wave motion; such as the number of cycles per second of an
alternating current.
Fuse
A protective device inserted in series with a circuit. It
contains a metal that will melt or break when current is increased beyond a
specific value for a definite period of time.
