T Link - Refer to Fuse Link, Type T.
Tap - A connection brought out of the winding
at some point between its extremities, usually to permit changing
the voltage or current ratio.
TCC (Time Current Curve) - TCCs are a series
of points plotted in a curve on log-log paper describing the
current-time reacting characteristics of a current interrupting
device. TCCs are a tool used by engineers to determine
coordination and correlation of devices.
Temperature Rise - The temperatures increase
over ambient due to load.
Temporary Overvoltage (TOV) - A temporary
overvoltage is define as an excursion of power frequency voltage
above the normal line-to-ground value. Such excursions are of
variable magnitude and duration.
Three Phase Power - Three separate outputs
from a single source. There is a phase difference of 120°
between any two of the three voltages and currents.
Time Current Curves (TCC) - A series of points
plotted in a curve on log-log paper describing the current-time
reacting characteristics of a current interrupting device; a tool
used by engineers to determine coordination and correlation of
devices.
Time to Impulse Sparkover - The time between
virtual zero of the voltage impulse causing sparkover and the
point on the voltage wave at which sparkover occurs.
Tracking - Irreversible degradation of surface
material from the formation of conductive carbonized paths.
Transformer
- A static electrical device which by electromagnetic induction
transfers electrical energy from one circuit to another circuit
usually with changed values of voltage and current in the
process.
Conventional
- A transformer that has no protective equipment (fuses,
breakers, arresters). They are used when the protective
equipment is provided by a fuse cutout attached to the pole
beside the transformer.
CSP
(Completely Self-Protected) - A transformer that contains an
internal breaker, an expulsion fuse and an arrester.
Dead
Front - A transformer that has bushing wells and inserts
or one-piece bushings used with elbows. The operator is not
exposed to live parts.
Live
Front - A transformer that has porcelain bushings with
one or two hole spades or eyebolts from primary terminations.
The operator is exposed to live parts.
Padmount
- A transformer designed for mounting on a concrete pad with
underground connecting cables.
Polemount
- A transformer designed for mounting on a pole with overhead
connecting lines.
Transient
- A high amplitude, short duration pulse superimposed on the
normal voltage.
Transient
Response - The ability of a circuit to faithfully reproduce a
transient applied to its input.
Turn
Ratio - The ratio of the number of turns in the high voltage
winding to that in the low voltage winding.
Glossary Index