User's Manual

ANSI Electric Meter v3.1 User’s Guide 87
Read-Only Key Allows data to only be read from the meter when it is accessed via the
optical port. A factory option can allow the date and time to also be
changed with this key.
Reverse (Export)
Energy
Energy delivered by the customer to the utility. Often considered a
tamper condition if the user is not legitimately generating energy (for
example, solar electric power) into the utility grid.
Rolling Demand A way to perform demand calculations. Rolling demand uses interlaced
measurement periods to calculate the peak power usage for a set period
of time, and continues to update the value as more time elapses to
generate a rolling average.
Root Mean Square
(RMS)
Refers to the most common mathematical method of defining the
effective voltage or current of an AC (Alternating Current) wave.
Sag A measured voltage quantity detected at a level below a defined
threshold.
Self-Read Method by which a meter performs a snapshot read of pertinent
registers along with a timestamp.
Summation Registers Meter registers that accumulate energy value readings for usage of
power over time. Also known as accumulators.
Swell (or Surge) A measured voltage quantity detected at a level above a defined
threshold.
Tariff A published list of rate schedules, terms, and conditions. Or, as in the
Echelon meter, the particular rate in effect at a given time.
Tier A tier usually refers to a single tariff or its associated registers in the
meter. In the NES system, tier can mean the same thing as tariff.
Tier Switch The time at which the meter changes from accumulating energy in one
set of tariff registers to a different set of tariff registers. This change is
either due to a pre-programmed switch, per the tariff schedule, or is due
to the activation of a new tariff schedule.
Time-of-Use (TOU) The recording of metering quantities based on a time schedule (time of
day, day of the week, month, and season). This allows the utility to track
energy usage over time, track usage during specific daily time periods,
set individual tariff rates for billing purposes, and provides information
for load control. A TOU schedule consists of one or more tariffs.
Unique Key A string of up to 20 characters which grants access to a meter or Data
Concentrator after it has been provisioned. Every device is assigned a
different Unique Key at time of manufacture.