letter am

Ammeter A meter designed to measure current.

Ampacity The continuous current rating in amperes for a conductor.

Ampere, Amp The basic unit for current. An ampere, also called an amp, is
equal to a current of 1 Coulomb per second. The symbol for
ampere is “A.”

Amplitude The total variation of a waveform. Amplitude can be expressed
as a peak value, peak-to-peak value, or effective value.


Analog A value that is continuously variable. Also used to describe

Analog Input An input to a system that can continuously vary over a range of
current or voltage such as 4 to 20 milliamps or 0 to 10 volts.
circuits that work with analog signals.

Analog Output An output from a system that can continuously vary over a
range of current or voltage such as 4 to 20 milliamps or 0 to 10
volts.

Apparent Power The vector sum of true power and reactive power. Apparent
power is calculated by multiplying current times voltage. The
unit for apparent power is the volt-ampere, abbreviated “VA.”


Arc Chute Assembly An assembly of metal plates surrounding circuit breaker or
contactor contacts. Arc chutes are used to reduce contact
damage by quickly extinguishing the arc created when contacts
open.