Electrical Definitions


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Electrical Definitions

Letter - C


An assembly of two or more wires.


Cable Clamps

A fitting use to secure cables to an enclosure. 


Cable Tray

A rigid structure use to support cables. A raceway normally have the appearance of a ladder. 



An enclosure that is designed for either surface mounting or flush mounting and is provided with a frame, mat, or trim in which a swinging door or doors are or can be hung.



An instrument use to measure the heat generated by an electrical current in a conductor.


Candlepower (or Candela)

Basic unit for measuring luminous intensity from a light source in a given direction.



The property of a capacitor that determines the quantity of electric energy that it can store.



A device consisting of two conducting surfaces separated by an insulator and having the ability of storing electric energy. Also called a condenser.



In a diode, the electrode that must be negative with respect to the anode (plate) to allow the diode to conduct.



Equipment is "certified" if it: 

(a) Has been tested and found by a qualified testing laboratory to meet applicable test standards or to be safe for use in a specified manner, and 

(b) Is of a kind whose production is periodically inspected by a qualified testing laboratory. Certified equipment must bear a label, tag, or other record of certification.



The number of electrons held on the capacitor plates. The act of forcing electrons onto the capacitor plates.



The condition of a capacitor which has the full charge it can receive from a given applied voltage.



A continuous path for the flow of electricity


Circuit breaker

A device designed to open and close a circuit by nonautomatic means and to open the circuit automatically on a predetermined overcurrent without damage to itself when properly applied within its rating.


Coefficient of Utilization

The amount of light (lumens) delivered in a workplace as a percent of the rated lumens of the lamp.


Cold Cathode Lamp

An electric-discharge lamp whose mode of operation is that of a glow discharge (Neon Lights).


Common Mode (CM)

The term refers to electrical interference which is measurable as a ground referenced signal. In true common mode a signal is common to both the current carrying conductors.


Common Node Noise

An undesirable voltage which appears between the power conductors and ground.



Rendered inaccessible by the structure or finish of the building. Wires in concealed raceways are considered concealed, even though they may become accessible by withdrawing them.



Metal wires and cables that allow the flow of electrical current.



A tubular raceway for data or power cables. Metallic conduit is common, although non-metallic forms may also be used. A conduit may also be a path or duct and need to be tubular.


Conduit Body

A separate portion of a conduit or tubing system that provides access through a removable cover(s) to the interior of the system at a junction of two or more sections of the system or at a terminal point of the system.


Connected Load

The combined continuous rating of all the equipment connected to the system or part of the system under consideration.


Connector, Pressure (Solderless)

A device that establishes a connection between two or more conductors or between one or more conductors and a terminal by means of mechanical pressure and without the use of solder.



The state of being whole, unbroken.


Continuos Load

A load where the maximum current is expected to continue for three hours or more. Rating of the branch circuit protection device shall not be less tan 125% of the continuos load.



A device or group of devices that serves to govern, in some predetermined manner, the electric power delivered to the apparatus to which it is connected.



A device which changes electrical energy from one form to another. There are several types of converters:


Crest Factor

The ratio of the peak or maximum value of a wave, to the r.m.s. value.



The movement of electrons through a conductor. Measured in amperes and its symbol is "I". 


Current Ratio

The current ratio of a current transformer is the ratio of r.m.s. primary current to r.m.s. secondary current, under specified conditions of load.


Current Transformer-(or CT)

A transformer used in instrumentation to assist in measuring current. It utilizes the strength of the magnetic field around the conductor to form an induced current that can then be applied across a resistance to form a proportional voltage.


Cutout Box

An enclosure designed for surface mounting and having swinging doors or covers.



One complete wave of positive and negative values of an alternating current. (See "Hertz")