Electro Industries Nexus 1262, Installation & Operation Manual

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Electro Industries/Gauge Tech Doc # E151701 Glossary-6
Serial Port: The type of port used to directly interface with a PC.
Slave Device: In Modbus communication, a Slave Device only receives a Request Packet from
a Master Device and responds to the request. A Slave Device cannot initiate
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.