residential wiring quarter 1 final
circuit breaker
a device designed to open and close circuit manually and to open the circuit automatically on a predetermined overcurrent without damage to itself when properly aligned within its rating
ground fault circuit interrupter GFCI
a device that protects people from dangerous levels of electrical current by measuring the current difference between two conductors of an electrical circuit in tripping to an open position if the measured value exceeds approximately 5 milliamperes
national electrical code NEC
a document that establishes minimum safety rules for an electrician to follow when performing electrical installations; It is published by the national fire protection association NFPA
auger
a drill bit with a spiral cutting edge used to bore holes in wood
cable
a factory assembly of two or more insulated conductors that have an outer sheathing that holds everything together The outside sheathing can be metallic or non metallic
connector
a fitting that is designed to secure a cable or length of conduit to an electrical box
short circuit
a little resistance path that results in a high value of current that flows around rather than through a circuit usually start circuits are unintended and happen when two hot conductors touch each other by mistake
conductor
a material that allows electrical current to flow through it examples are copper aluminum and silver
utility box
a name used to refer to a metal single gang surface mounted device box also called a handy box
bimetallic strip
a part of a circuit breaker that is made from two different metals with an equal thermal expansion rates as the strips heat up it will tend to bend
chuck
a part of a power drill used for holding a drill bit in a rigid position
knockout
a part of an electrical box that is designed to be removed or knocked out so that a cable or wasteway can be connected to the box
load (electrical)
a part of an electrical circuit that uses electrical current to perform some function an example would be a light bulb produces light or electric motor produces mechanical energy
wire nut
a piece of electrical equipment used in mechanically connect to remote conductors together
outlet
a point on the wiring system at which current is taken to supply a piece of electrical equipment such as a light fixture or appliance
crimp
a process used to squeeze a solderless connector with a tool do that it will stay on a conductor
bender
a tool used to make various bends in electrical conduit raceway
romex
a trade name for nonmetallic sheath cable NMSC
polarized plug
a two-prong plug that distinguishes between the grounded conductor and the hot conductor by having the grounded conductor prong wider than the hot conductor prong this plug will fit into receptacle only one way
handy box
a type of metal surface mounted device box used to hold only one device
load center
a type of panel board normally located at the service entrance and a residential installation and usually containing the main service disconnect switch
Ampere
a unit of electric current equal to a flow of one coulomb per second.
Arc blast
a violent electrical condition that causes molten metal to be thrown into the air
and a work situation where an electrician's hands get wet while operating a portable drill what would be true about the bodies resistance
body resistance is substantially decreased in severe shotgun occur
personal protective equipment PPE
equipment for the eyes face head and extremities protective clothing respiratory devices and protective shields and barriers
class A fire
fires that occur in ordinary combustible materials such as wood rags and paper
class d fires
fires that occur with combustible metals such as powdered aluminum and magnesium
class B fire
fires that occur with flammable liquids such as gasoline oil grease paints and thinners
If cables are running through wood members do not have the designated clearance what must be placed on top
is there a plate at least 1/16 of an inch
NMS-B
used a new homes that have home automation systems using the latest technology The cable contains the power conductor's telephone wires coaxial cables for videos and other data conductors all in the same cable
rigid metal conduit
(RMC) typically made of steel and is galvanized to enable it to resist resting sometimes referred to as heavy wall conduit
cables that run through framing members must not be less than how many inches from the nearest edge of the framing member
1 1/4 inch
types of SE cable
1. SEU- used for service entrance installations It contains three conductors 2. SER- similar to type SEU but has four conductors wrapped in a round configuration also used as a feeder from the main service panel to a sub panel 3. USE- used for underground service entrance installations
components of a fire triangle
1. fuel- any material that can burn 2. heat - raises the feel to its ignition temperature 3. oxygen - required to sustain combustion
what amount of current does it take to cause ventricular fibrillation
1000-4300 milliamperes
outlet box
A box that is designed for mounting a receptacle or lighting fixture
junction box
A box whose purpose is to provide a protected place for splicing electrical conductors
insulated
A conductor that is covered by a material that is recognized by the national electric code as an electrical insulation
hazard
A danger or risk.
arc-flash
A dangerous condition associated with the possible release of energy caused by an electric arc
material safety data sheet MSDS
A form that lists and explain each of the hazardous materials that electricians may work with so they can safely use the material and respond to an emergency situation
overload
A larger than normal current amount flowing in normal current path
insulator
A material that does not allow electrical current to flow through it examples are rubber plastic and glass
switch box
A name used to refer to a box that contains switches
power source
A part of an electrical circuit that produces the voltage required by the circuit
device
A piece of electrical equipment that is intended to carry but not use electrical energy examples include switches lamp holders and receptacles
American wire gauge AWG
A scale of specified diameters and cross sections for wire sizing that is the standard wire sizing scale in the United States
antioxidant
A special compound that is applied to expose aluminum conductors is purpose is to inhibit oxidation
shall
A term used in the national electrical code that means the rule must be followed
safety switch
A term used sometimes to refer to a disconnect switch A safety switch may use fuses or a circuit breaker to provide overcurrent protection
armored clad cable
AC also known as BX cable
electrical metallic tubing
EMT "thinwall" cannot be threaded
electrical nonmetallic tubing
ENT "smurftube" blue color
types of plug fuses
Edison base and type s
flexible metal conduit
FMC "greenfield"
multi-wire circuit
I circuit that consist of two or more ungrounded hot connectors that have a voltage between them and a grounded neutral conductor that has the same voltage between it and each of the ungrounded connectors
panel board
I panel design to accept fuses or circuit breakers used for the protection and control of lighting heating and power circuits It is designed to be placed in a cabinet and placed in or on a wall It is accessible only from the front
intermediate metal conduit
IMC threaded on each end and also comes with a coupling on one end, lighter weight
liquid tight flexible metal conduit
LFMC
liquid tight flexible non-metallic conduit
LFNC
metal clad cable
MC
non-metallic sheathed cable
NM also known as Romex
rigid polyvinyl chloride conduit
PVC grey colored for electrical work
ampacity
The current in amperes that a conductor can carry continuously under the conditions of use without exceeding the temperature rating
plug
The device that is inserted into receptacle to establish a connection between the conductors of the attached flexible cord and the conductors connected to the receptacle
arc
The flow of a high amount of current across an insulating medium like air
voltage
The force that causes electrons to move from atom to atom in a conductor
resistance
The opposition to current flow
sheath
The outer covering of a cable that is used to provide protection to hold everything together as a single unit
service entrance
The part of the wiring system where electrical power is supplied to the residential wiring system from the electric utility It includes the main panel board the electric meter over current protection devices and service conductors
electrical shock
The sudden stimulation of nerves and muscles caused by electricity flowing through the body
torque
The turning force applied to a fastener
ohm
The unit of measure for electrical resistance
volt
The unit of measure for voltage
underground feeder cable
UF
scaffolding
also referred to as staging a piece of equipment that provides platform for working in high places The parts are put together at the job site and then taken apart and reconstructed one needed at another location
ground fault
an accidental connection of a hot electrical conductor and a grounded piece of equipment or the grounded circuit conductor
copper clad aluminum
an aluminum conductor with an outer coating of copper that is bonded to the aluminum core
circuit (electrical)
an arrangement consisting of a power source, conductors, and a load
fitting
an electrical accessory like a lock nut that is used to perform a mechanical rather than an electrical function
grounding
an electrical connection to an object that conducts electrical current to the Earth
device box
an electrical device that is designed to hold devices such as switches and receptacles
double insulated
an electrical power tool type constructed so the Case is isolated from electrical energy and is made of a non-conductive material
cabinet
an enclosure for a panel board that is designed for either flush or surface mounting a swinging door is provided
fuse
an overcurrent protection device that opens a circuit when the fusible link is melted away by the extreme heat caused by an over current
national electrical manufacturers association NEMA
and an organization that establishes certain construction standards for the manufacturers of electrical equipment
raceway
and enclosed metal or nonmetallic channel designed to hold wires or cables examples are rigid metal conduit electrical metal conduit electrical non-metallic conduit and flexible metal conduit
overcurrent
any current and access of the rated current of equipment or the ampacity of a conductor It may result from an overload a short circuit or a ground fault
how far apart must boxes be placed and the fire resistant wall
boxes can all be placed back to back in the same stud cavity unless the balls are not fire rated and fire rated walls of boxes must be placed in minimum of 24 inches apart even when they are in different stud cavities
NM-B
by far the most common type used and has a flame retardant moisture resistant non-metallic outer jacket It can be used in dry locations only
spliced
connecting two or more conductors with a piece of approved equipment like a wire nut splices must be done in approved electrical boxes
Ohm's Law
current = electrical force/ resistance The mathematical relationship between current voltage and resistance and electrical circuit
class c fires
fires that occur in or near electrical equipment such as motors switchboards and electrical wiring
ganging
joining two or more device boxes together for the purpose of holding more than one device
NMC-B
not often used in residential work It has a flame retardant and moisture fungus and corrosion resistant non-metallic outer jacket and can be used in dry or damp locations
occupational safety and health administration OSHA
since 1971 OSHA's job has been to establish and enforce workplace safety rules
pry out
small parts of electrical boxes that can be pride open with a screwdriver and twist it off so that a cable can be secured to the box
current
the intensity of electron flow and a conductor
ventricular fibrillation
very rapid irregular contractions of the heart that result in the heartbeat and poles going out of rhythm with each other
approved
when a piece of electrical equipment is approved it means that is it acceptable to the authority having jurisdiction AHJ
