alternating current

AC. Current that reverses direction at regularly recurring intervals of time. Alternating current alternates 60 times per second, or 60 hertz, in the United States.

amperage

A measurement that indicates the amount of current flowing in a circuit. Amperage is measured in amperes.

amperes

A. A unit of electrical measurement that describes both an amount of electricity and the time it takes for electricity to travel a certain distance. One ampere, or amp, is the smallest quantity measurement of electrical current per second.

arc burns

A burn sustained from an electric arc. Arc burns result either from the extreme heat produced by the arc or through radiation.

arc fault circuit interrupters

AFCI. A safety device used in outlets that detects arcing in a circuit. Arc fault circuit interrupters disable the circuit immediately if they detect any type of problem in the circuit.

arc welding

A welding process that uses heat generated by electricity to melt filler and base metals to form an airtight weld. Arc welding may lead a person to experience an arc burn.

atoms

The smallest distinguishable unit of a material. Atoms maintain the same characteristics of the material as a whole.

battery

A device that converts chemical energy into electrical energy. Batteries are a source of current.

bus bar

A thick, rigid strip or bar of copper that serves as a common connection between several circuits. Bus bars are contained in an electrical box.

cardiac arrest

The sudden, temporary or permanent, stopping of the heart. Cardiac arrest may occur if a person experiences electric shock.

chassis

The frame of a machine. A chassis is used to absorb stray electric charge.

chassis ground

An internal grounding system that uses a grounding conductor that runs from a machine's circuit to its frame. A chassis ground is used for objects and machines that cannot be connected to a pole embedded in the earth.

class C fire extinguisher

A type of fire extinguisher that is approved for putting out fires caused by live electrical equipment. Class C fire extinguishers cannot be used to extinguish all types of fires.

conductors

Material that allows for the free movement of electrons, therefore allowing the easy flow of electricity. Most conductors are metals.

copper

A ductile, conductive metal. Copper is often used in electrical circuits.

current

The flow of electricity through a circuit. Current is measured in amperes, also known as amps.

de-energized

A state at which all stored energy in a system is removed. A de-energized system removes the risk of electric shock.

defibrillator

A machine that is used to reset an irregular heartbeat. A defibrillator can be used to prevent death when ventricular fibrillation occurs.

earmuffs

A protective device that covers the entire outer ear. Earmuffs block noise and prevent debris from entering the ear.

earplugs

A protective device that is placed in the ear canal. Earplugs prevent excessive noise from entering the ear and damaging it.

electric arc

The area in which electricity passes from an electrode to another conductor to produce extreme heat and light. Electric arcs are used in welding and in some types of industrial furnaces.

electric shock

The flow of electricity through the body. Severe electric shock can be fatal.

electrical box

The system that serves as the source of electricity for a structure. The electrical box is where the main electrical service comes in and is distributed throughout a building or household.

electrical burns

A burn sustained from handling wiring or electrical equipment that has been improperly maintained. Electrical burns are typically sustained on the hands.

electrical circuit

A completely enclosed path of electrical current consisting of various devices. An electrical circuit usually includes a source, path, load, and control.

electricity

The energy created by the movement of electrons. Electricity can be converted into light, heat, or motion.

electrocution

Death due to electricity. The risk of electrocution can be decreased by the use of GFCI outlets or plugs.

electrons

A negatively charged particle that orbits the nucleus of an atom. Electrons flow between atoms in electrical conductivity.

face shields

A protective device that guards the face and eyes from debris. Some face shields protect users from intense UV light or radiation.

flexible wiring

A type of movable conductor like an extension cord. Flexible wiring is not meant for permanent use.

frame

The physical body of a machine. Frames are often composed of metals and plastics.

ground

A source that absorbs stray electrical charge. The best source for ground is the earth because of its size.

ground fault circuit interrupter

GFCI. A type of switch that disables power to the electric circuit if electric current comes into contact with water. Ground fault circuit interrupters should be used whenever there is a chance for electricity to come into contact with water.

grounded conductors

The neutral wire in an electrical circuit. Grounded conductors, also known as return conductors or neutral wires, are typically the white wires in a typical wiring configuration that return power to the source.

grounded pole

A metal structure embedded in the earth to which a grounding system sends stray currents. A grounded pole connects to a circuit at the bus bar.

grounding

A means of providing a safe path for electricity in case it strays from its intended path. Grounding can be provided by electrical wires.

grounding conductors

A wire in an electrical system that provides a low-resistance path to ground for stray current. The grounding conductor is usually bare copper or covered with green insulation.

hard hats

A lightweight head covering that protects against impact, low-clearance areas, and electric shock. Hard hats are usually made of plastic.

hazards

A source of danger or possible injury. Hazards, such as falling objects or chemical exposure, can affect a person externally and internally.

hot wires

An electrically charged wire that provides power to the load. The hot wire is usually covered with black insulation.

insulators

Materials or elements that have little electrical conductivity and high resistance to electrical charges. Most insulators are plastics and ceramics.

live circuit

An electrical circuit that has power moving through it. A live circuit always has voltage present within it.

lockout device

A safety device that holds a switch in an off position or covers the switch so that it is inaccessible. A lockout device should only be unlocked by a person authorized to do so.

lockout/tagout

The proper locking and labeling of machines that are hazardous to nearby employees. Lockout/tagout is a method of protecting employees from accidental machine startup.

milliamperes

A unit that measures current. A milliampere is equal to one thousandth of an ampere.

milling machine

A machine that uses a muti-point tool to remove metal from the surface of a workpiece. Milling machines are commonly used to machine slots, grooves, and flat surfaces in rectangular workpieces.

multi-purpose fire extinguisher

A type of fire extinguisher that is approved to put out class A, B, and C fires. A multi-purpose fire extinguisher may be used to put out electrical fires.

National Electrical Code

NEC. The standard for minimum safe electrical installations. The National Electrical Code is adopted in some form as law in all 50 states.

National Fire Protection Association

NFPA. A non-profit organization that maintains standards of public safety and fire prevention. The National Fire Protection Association was originally formed to develop standards for sprinkler systems.

neutral

A material or structure that is not electrically charged. Neutral objects often include specific wires and even the earth.

neutral wires

The wire through which electricity returns from a load to the source. The neutral wire is typically white and may also be called the grounded conductor or return conductor.

neutrons

An atomic particle with no charge. Neutrons are located in the nucleus of an atom.

NIOSH

National Institute for Occupational Safety and Health. An organization that researches and develops workplace health and safety recommendations. The National Institute for Occupational Safety and Health, along with OSHA, regulates electrical safety standards.

non-conductive

A material's inability to act as a path for the movement of electricity. Non-conductive materials like rope or wood must be used to free a person from electric shock.

nucleus

The center portion of an atom. The nucleus contains protons and neutrons, while electrons orbit the nucleus.

Occupational Safety and Health Administration

OSHA. A government agency that sets the standards for working conditions in the United States. The Occupational Safety and Health Administration ensures that employees work in safe and healthy environments.

ohms

Ω. A unit of measurement for electrical resistance. Ohms impeded or obstruct current flow.

paralysis

Loss or impairment of the use of a body part or region of the body. Paralysis may prevent a person from making certain movements or performing specific functions.

paralyze

To make a body part or region of the body have impaired or loss of movement. A paralyzed person may be unable to make certain movements or perform specific functions.

path

A conductor that directs electricity in a circuit. A path is often made of copper wire.

plastic

A lightweight material that resists corrosion and is easily shaped. Plastic is an insulator.

power source

A device that generates electricity. Power sources can include batteries and generators.

protons

A positively charged particle within an atom. Protons are located in the nucleus of an atom.

radiation

Energy transmitted through space as waves, such as radio waves or light waves. Radiation can be caused by an electric arc and can burn the skin.

resistance

The opposition to current flow. Electricity flows in the path of least resistance.

respiratory paralysis

Loss or impairment of the use of the respiratory organs. Respiratory paralysis can result from electric shock and keeps a person from breathing.

return conductors

The neutral wire in an electrical circuit. Return conductors, also known as grounded conductors or neutral wires, are typically the white wires in a typical wiring configuration that return power to the source.

rubber

An elastic material made from the latex sap of a rubber tree. Rubber is an insulator.

safety glasses

A type of eye protection that shields the eyes. Safety glasses offer protection from impact, dust, chips, splashes, and sometimes UV light.

safety goggles

A type of tight-fitting eye protection that completely covers the eyes, sockets, and surrounding facial area. Goggles offer protection from impact, dust, chips, splashes, and sometimes UV light.

tagout devices

A warning device, such as a tag, that is securely attached to a machine or power source to alert employees that equipment is not to be operated until the tag is removed. Tagout devices are always used with lockout devices.

terminal

A connecting point in a circuit to which a wire can be attached to connect a component. Terminals on batteries can be negatively or positively charged.

thermal contact burns

A burn sustained from a fire or extreme heat. Thermal contact burns can result from electrical explosions.

three-stage safety model

A safety model designed to identify and manage hazards by recognizing, evaluating, and controlling them. The three-stage safety model is recommended to employers by NIOSH.

variables

Factors in electricity that change according to the situation. Variables in electrical work include amperage, voltage, and resistance.

ventricular fibrillation

Rapid and ineffective heartbeats. Ventricular fibrillation can be caused by electric shock and may lead to death within minutes if a defibrillator is not used.

voltage

A measure of electrical pressure or potential known as electromotive force. Voltage is measured in volts.

volts

V. A unit of measurement of voltage. Volts measure electromotive force or pressure.

electrically charged

A wire or device through which current flows. Electrically charged objects can deliver electric shocks to anyone who touches them.

electrically charged

The state in which a wire or device has current flowing through it. Electrically charged objects pose the risk of electric shock.

personal protective equipment

PPE. Any of the various articles of clothing or safeguarding devices that workers wear to ensure their safety. Common personal protective equipment worn during electrical work includes safety classes, rubber-soled footwear, and gloves.

personal protective equipment

PPE. Any of the various articles of clothing or safeguarding devices that workers wear to ensure their safety. Common personal protective equipment worn during electrical work includes safety glasses, rubber-soled footwear, and gloves.

PPE

Personal protective equipment. Any of the various articles of clothing or safeguarding devices that workers wear to ensure their safety. Common PPE worn during electrical work includes glasses, rubber-soled footwear, and gloves.

PPE

Personal protective equipment. Any of the various articles of clothing or safeguarding devices that workers wear to ensure their safety. Common PPE worn during electrical work includes safety glasses, rubber-soled footwear, and gloves.

ultraviolet light

UV light. A type of radiation that is above violet in the color spectrum. Ultraviolet light is not visible to the human eye.

ultraviolet light

UV light. Light that is invisible to the naket eye because it consists of wavelengths shorter than those of visible light. Ultraviolet light can cause serious damage to eyesight.