Glossary of Terms - A

AL - Aluminum

Alternating Current (ac) - A flow of electricity which reaches maximum in one direction, decreases to zero, then reverses itself and reaches maximum in the opposite direction. The cycle is repeated continuously. The number of cycles per second is equal to the frequency.

Amalgam - A mixture of different elements.

Amalgamate - The forming of an amalgam; the union of two materials; an alloy.

Ambient Temperature - The temperature of the atmosphere of surrounding environment. Typically defined by industry standards as 25 C.

Ampere (A) - Unit of electrical current flow, or rate of flow of electrons.

ANSI - American National Standards Institute; Electrical standard developed and published as a result of recommended practices and studies made by NEMA and IEEE.

ANSI 386 - American National Standards instituted Standard for high-voltage elbow connectors. Last issue date, 1985. Deadfront arrest interfaces are defined in this standard.

ANSI/IEEE C37.4 - Industry standards for fuses, air switches and accessories.

ANSI/IEEE C62-11 - American Nation Standards Institute Standard for metal oxide surge arresters. Last issue date, 1993.

Arc - Sparking that results when undesired current flows between two point of differing potential.

Arc Follower - An arc extinguishing extension on the end of an ELS current-limiting fuse, an essential part of the EL Bay-O-Net holder's loadbreak rating.

Arc Strangler Loadbreaking Device - The arc strangler sleeve (red cap) and cocking mechanism on a hinge-style mounted NX or NXII current-limiting fuse that allows all current magnitudes from excitation current through 200 amps to be interrupted positively and safely by opening the fuse with a switchstick.

Arc Strangler Switchblade - Switchblade with an arc strangler loadbreaking device for hinged style mounting.

Arc Voltage - The reaction of a circuit's inductance to the rate of current change in the circuit; E = L(di/dt); when a current-limiting fuse operates, there is an associated arc voltage on the system.

Arrester - A protective device for limiting surge voltages on equipment by diverting surge current and returning the device to its original status. It is capable of repeating these functions as specified.

Arrester, Deadfront Type - An arrester assembled in a shielded housing providing system insulation and conductive ground shield, intended to be installed in an enclosure for the protection of underground and padmounted distribution equipment and circuits.

Arrester, Disconnect - A means for disconnecting an arrester after failure in order to prevent a permanent fault on the circuit. It also gives indication of a failed arrester.

Arrester, Distribution, Heavy Duty Class - An arrester normally used to protect overhead distribution systems exposed to severe lightning currents.

Arrester, Distribution, Light Duty Class - An arrester normally installed on and used to protect underground distribution systems where the major portion of the lightning stroke current is discharged by an arrester located at the overhead line/cable junction.

Arrester, Distribution, Normal Duty Class - An arrester normally used to protect overhead distribution systems exposed to typical lightning currents.

Arrester, Liquid-Immersed Type - An arrester designed for use immersed in an insulating liquid.

Arrester, Riser Pole Type - An arrester for pole mounting normally used to protect underground distribution cable and equipment.

Arrester Voltage Rating - RMS value of the maximum 60 Hz voltage to which an arrester should be subjected, even under transient conditions.

Arrestor - See Arrester

Asymmetric - A term used to explain the offset current waveform that can occur when a fault is initiated; the composite quantity of the transient current (dc component) and the steady state current (ac component); usually considered to be 1.6 times the symmetric for most electrical distribution systems.

ATZ - Cooper Power Systems' station class, heavy duty, porcelain housed arrester.

Aught - Standard conductor size, i.e. 4 aught designation 4/0.

AWG - American Wire Gauge: A conductor size designation, i.e., size #2 through 4/0. (Refer to aught.)

AZF - Cooper Power Systems' intermediate class, porcelain housed arrester.

AZL - Cooper Power Systems' distribution class, heavy duty, porcelain housed arrester.

AZLP - Cooper Power Systems' distribution class, heavy duty, polymer housed arrester with 20 kA fault withstand rating.

AZR - Cooper Power Systems' distribution class, heavy duty, riser pole, porcelain housed arrester.

AZRP - Cooper Power Systems' distribution class, heavy duty, riser pole, polymer housed arrester with 20 kA fault withstand rating.

AZS - Cooper Power Systems' distribution class, normal duty, porcelain housed arrester.

AZSP - Cooper Power Systems' distribution class, normal duty, polymer housed arrester with 20 kA fault withstand rating.

AZU - Cooper Power Systems' distribution class, heavy duty, under-oil arrester.

Glossary Index