Electrical Definitions


 Copyright - Durand & Associates  

Electrical Definitions

Letter - I


(as applied to equipment). Recognizable as suitable for the specific purpose, function, use, environment, application, and so forth, where described in a particular Code requirement.



Forces which resist current flow in AC circuits, i.e. resistance, inductive reactance, capacitive reactance.


In Sight From

Within Sight From, Within Sight). Where this Code specifies that one equipment shall be “in sight from,” “within sight from,” or “within sight,” and so forth, of another equipment, the specified equipment is to be visible and not more than 15 m (50 ft) distant from the other.


Inductive Load

An inductive load is a load in which the current lags behind the voltage across the load. (See Non-Inductive Load)



The ability of a coil to store energy and oppose changes in current flowing through it. A function of the cross sectional area, number of turns of coil, length of coil and core material.


Induction Motor

An alternating current motor, either single phase or polyphase, comprising independent primary and secondary windings, in which the secondary receives power from the primary by electromagnetic induction.


Input Power Frequency

The frequency range that can be input into the suppressor without damaging it.


Instrument Transformer

A transformer (current or potential) suitable for use with measuring instruments; i.e., one in which the conditions of the current, voltage and phase angle in the primary circuit are represented with acceptable accuracy in the secondary circuit.


Interrupting Rating

The highest current at rated voltage that a device is intended to interrupt under standard test conditions.



(as applied to location). Not readily accessible to persons unless special means for access are used.