communication.

Swell:

A voltage quality event during which the RMS voltage is higher than normal for

 

a period of time, typically from 1/2 cycle to 1 minute.

THD:

Total Harmonic Distortion is the combined effect of all harmonics measured in a

 

voltage or current. The THD number is expressed as a percent of the

 

fundamental. For example, a 3% THD indicates that the magnitude of all

 

harmonic distortion measured equals 3% of the magnitude of the fundamental

 

60Hz quantity.

Time Stamp:

A stored representation of the time of an event. Time Stamp can include year,

 

month, day, hour, minute and second and Daylight Savings Time indication.

TOU:

Time of Use.

Uncompensated Power: VA, Watt and VAR readings not adjusted by Transformer Loss Compensation.

V2T Threshold:

Data will stop accumulating when voltage falls below programmed level.

Voltage Imbalance:

The ratio of the voltage on a phase to the average voltage on all phases.

Voltage Quality Event: An instance of abnormal voltage on a phase. The events the meter will track

 

include sags, swells, interruptions and imbalances.

VT Ratio:

The Voltage Transformer Ratio is used to scale the value of the voltage to the

 

primary side of an instrument transformer. Also referred to as PT Ratio.

Voltage, Vab:

Vab, Vbc, Vca are all Phase-to-Phase voltage measurements. These voltages are

 

measured between the three phase voltage inputs to the meter.

Voltage, Van:

Van, Vbn, Vcn are all Phase-to-Neutral voltages applied to the monitor. These

 

voltages are measured between the phase voltage inputs and Vn input to the

 

meter. Technologically, these voltages can be “measured” even when the meter

 

is in a Delta configuration and there is no connection to the Vn input. However,

 

in this configuration, these voltages have limited meaning and are typically not

 

reported.

Voltage, Vaux:

This is the fourth voltage input measured from between the Vaux and Vref

 

inputs. This input can be scaled to any value. However, the actual input

 

voltage to the meter should be of the same magnitude as the voltages applied to

 

the Va, Vb and Vc terminals.

Glossary-6

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