Cooper Power Systems - Glossary of Terms - P
Padmount Transformer - A transformer designed
for mounting on a concrete pad with underground connecting
cables.
Parking Stand Arrester - A metal oxide
varistor elbow with a parking stand bracket used for overvoltage
protection of open point cable runs.
Peak Demand - The maximum integrated demand
during a time period.
Peak Line Current - Maximum instantaneous
current during a cycle.
Percent IR (%IR) - The voltage drop due to
conductor resistance at rated current expressed in percent of
rated voltage.
Percent IX (%IX) - The voltages drop due to
reactance at rated current expressed in percent of rated voltage.
Percent IZ (%IZ) - The voltage drop due to
impedance at rated current expressed in percent of rated voltage.
Phase - Classification of an ac circuit
usually single-phase, two wire or three wire; two-phase, three
wire or four wire; or three-phase, three wire or four wire.
Power Fuse - In accordance with ANSI/IEEE
C37.46, a power fuse (expulsion and current-limiting) has high
voltage ratings of 2.8-167 kV and x/r ratios of 15-25 (refer to
distribution fuse).
Power Follow Current - Refer to Follow
Current.
Power-Frequency Sparkover Voltage - The rms
value of the lowest power-frequency sinusoidal voltage that will
cause sparkover when applied across he terminals of an arrester.
Power-Frequency Withstand Voltage - A
specified rms test voltage at power frequency that will not cause
a disruptive discharge.
Power Outage - An interruption of power.
Primary Taps - Taps added in the primary
winding (see Tap).
Primary Voltage Rating - Designates the input
circuit voltage for which the primary winding is designed.
Primary Winding - A winding connected to the
voltage source or input.
Probe - The male connecting piece of a
Deadfront M.O.V.E. arrester.
Prorated Section - A complete, suitably housed
part of an arrester comprising all necessary components,
including gaseous medium, in such a proportion as to accurately
represent, for a particular test, the characteristics of a
complete arrester.
Puncture - Term used when a disruptive
discharge occurs through a solid dielectric. A disruptive
discharge in a solid dielectric produces a permanent loss of
dielectric strength; in a liquid of gaseous dielectric, the loss
may be only temporary.
Glossary Index