Glossary – Rockwell Automation 1426 PowerMonitor 5000 Unit User Manual
Page 383
Rockwell Automation Publication 1426-UM001F-EN-P - November 2013
383
Glossary
The following terms and abbreviations are used throughout this manual. For
definitions of terms not listed here, refer to the Allen-Bradley Industrial
Automation Glossary, publication
.
Amperes
The units of electrical current or rate of flow of electrons. One volt across one
ohm of resistance causes a current flow of one ampere. A flow of one coulomb per
second equals one amp.
Apparent Power
The product of voltage magnitude and current magnitude in a circuit. Units are
VA or some multiple thereof.
Balanced Load
An alternating, current power system consisting of more than two current
carrying conductors in which these current carrying conductors all carry the same
current.
Billing Demand
The demand level that a utility uses to calculate the demand charges on the
current month's bill. Various methods can be used to determine the value, such as
minimum demand, peak demand or a ratchet clause. It can be based on Watt
Demand, VA Demand, VAR Demand or some combination of these. A rate at
which a transmission occurs, where one baud equals one bit per second.
Burden
The electrical load placed on source of VA or the load an instrument or meter
places on a current or potential transformer. All current and potential
transformers have a rated burden that cannot be exceeded or else transformer
transformation accuracy deteriorates.
Capacitor
A device consisting essentially of two conducting surfaces separated by an
insulating material or dielectric. A capacitor stores electrical energy, blocks the
flow of direct current, and permits the flow of alternating current to a degree
dependent upon the capacitance and frequency. Capacitors can also be used to
adjust the power factor in a system.
Connected Load
The total load that a customer can impose on the electrical system if everything
was connected at one time. Connected loads can be measured in horsepower,
watts or volt-amperes. Some rate schedules establish a minimum demand charge
by imposing a fee per unit of connected load.
Current Transformer (CT)
A transformer, intended for measuring or control purposes, designed to have its
primary winding connected in series with a conductor carrying the current to be
measured or controlled. CT's step down high currents to lower values that can be
used by measuring instruments.
Current Transformer Ratio
The ratio of primary amperes divided by secondary amperes.
Data Table
Power monitor data is organized in data tables similar to those found in an
SLC 5/03 Programmable Controller. The detailed data table definitions are
covered in