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CHAPTER 3 -
TERMINOLOGY
3.1
ABREVIATIONS
HTA:
high voltage used for electrical supply, with anominal RMS ranging from 1kV to 50Kv
HTB:
high voltage used for electrical supply, with a nominal RMS superior to 50kV
LV
: Low Voltage electrical supply, with a nominal RMS value ofless than 1kV.
TRIDENT only directly measures LV with a the nominal RMS value of less than 400V.
VT
: Voltage transformer, placed between the high voltage to be measured and the TRIDENT inputs.
CT
: Current transformer. In this document clamps with current outputs (for TRIDENT 3U3I /I) and
clamps with voltage outputs (for TRIDENT 3U3I /U) have the same abbreviation.
3.2
GLOSSARY
Voltage dips
:
rapid and temporary voltage drop measured below the programmed threshold,
followed by a re-establishment of the voltage, or an interruption.
Overvoltage
:
temporary voltage increase, slow or rapid, measured above the programmed threshold.
Brief interruption
: disappearance or large voltage drop measured during a brief instant. According to the
EN50160 standard, a brief interruption is less than 3mn.
Long interruption
: disappearance or large drop of voltage. According to the EN50160 standard, a long
interruption is over 3mn.
Rapid Variation, voltage fault
:
abrupt variation of the voltage RMS value measured over at least
one cycle (rise, dip or break) followed by a re-establishment of the
voltage or a change to another type of rapid variation. A rapid
variation over the detection thresholds of TRIDENT is considered as
a voltage fault.
Slow Variations
:
variations of the mean RMS values of the physical parameter measured (voltage,
current or power).
