National Electric Code (NEC) & Wiring Methods Flashcards
Ampacity
The current, in amperes, a conductor can carry continuously under the conditions of use without exceeding its temperature rating.
AWG
American Wire Gauge
Branch Circuit
The circuit conductors between the final over-current device protecting the circuit and the outlet(s).
CMA
Circular Mil Area
Circular Mil Area (CMA)
A method of sizing the cross sectional area of wire arrived at by determining the diameter in thousandths of an inch and then squaring that value.
Color Code
A standardized method of conductor identification.
EMT
Electrical Metallic Tubing
Electrical Metallic Tubing (EMT)
A thin wall conduit that is easily bent and does not use threaded fittings.
Feeder
All circuit conductors between the service equipment or the source of a separately derived system and the final branch circuit overcurrent device.
Galvanic Action
The chemical reaction between dissimilar metals, actually electrolysis.
Grounded Conductor
A system or circuit conductor that is intentionally grounded.
Grounding Conductor
A conductor used to connect equipment or the grounded circuit of a wiring system to a grounding electrode or electrodes.
Hot wire
Slang term for ungrounded conductor.
Insulation Type Letter
A coded letter found on insulation that defines its type.
Kcmil
Abbreviation for one thousand circular mils (previously known as MCM).
Mil
Unit of measurement equal to .001 inch that is used to measure wire diameter.
National Electrical Code (NEC)
The safety standard for electrical installations in buildings and other structures.
NFPA
The National Fire Protection Association. The organization that sponsors and writes the NEC.
Resistivity
The resistance in a wire per mil-foot.
Raceway
An enclosed channel of metal or nonmetallic materials designed expressly for holding wires, cables, or busbars, with additional functions as permitted in this (NEC) code.
Service
The conductors and equipment for delivering energy from the electrical supply system to the wiring system of the premises served.
Ungrounded conductor or “hot” wire
A system or circuit conductor that is not grounded but rather has a potential to ground.
Circuit protection devices and switches are located in the ungrounded conductors. True or false?
True
Resistance of a wire is directly proportional to its length and inversely proportional to its ___.
cross-sectional area
Resistance of a wire also depends on the kind or type of ___.
material
What are important factors when selecting the proper size wire?
length, type, and cross-sectional area
