User's Manual

84 Meter Specifications
Appendix C
Glossary
The following describes terms as they are used in this document and other related
NES documents.
Active Energy The measurement of active power used over a period of time.
Active Power Total power is the product of the voltage and current. Active power is
the part of total power that is expended due to a resistive load. It is
considered to do the work in the system and is also called the real power.
The value is determined by multiplying the total power by the cosine of
the phase angle between voltage and current.
Accumulators Meter registers that accumulate energy value readings for usage of
power over time. Also known as summation registers.
AMR Automated Meter Reading.
ANSI C12.18 An ANSI (American National Standards Institute) standard specifying
hardware and low-level protocol for meter communication over optical
ports.
ANSI C12.19 An ANSI standard specifying application-level meter information and
transfer format.
Apparent Power Apparent power is total power. It is the product of voltage and current.
It is also the vector sum of active and reactive power.
Block Demand One way to perform demand calculations. Block demand uses
independent measurement periods that are intended to measure the
peak power usage for a specific time period.
CT Current Transformer. A current transformer is used, in conjunction with
a meter connected to it, to measure the current flow in a conductor that
is passed through the middle of the CT. A CT is typically used to
measure current that is too high to pass directly through the meter.
DC-1000 Data
Concentrator
Data Concentrators supervise electrical meters (and other devices) over
an A-Band power line channel, and communicate with NES System
Software located at the utility’s service center. DC-1000 is a model
number for one version of the Data Concentrator.