Safety for Electrical Work 111

amperage

I. The amount of current flowing in a circuit. Amperage is measured in amperes (A), or amps.

amperes

A. A unit of measurement that describes both an amount of electricity and the time it takes for electricity to travel a certain distance. Amperes, or amps, are used to measure amperage.

Amps

A. A unit of measurement that describes both an amount of electricity and the time it takes for electricity to travel a certain distance. Amps, or amperes, are used to measure amperage.

anti-static floor mats

A floor covering made of a material that conducts electricity away from a person or object and into the ground. Antistatic floor mats can prevent static electricity discharge that could damage equipment.

anti-static wrist straps

A safety device worn around the wrist that conducts electricity away from the wearer and into a grounded workstation. Anti-static wrist straps prevent the buildup of static electricity in a person’s body.

arc burns

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

arc fault circuit interrupters

AFCIs. A safety device used in outlets that detects arcing in a circuit. Arc fault circuit interrupters disable the circuit immediately if they detect an arc in the circuit.

arc flash

An electrical explosion resulting from a short circuit that creates an electric arc between exposed conductors. Arc flash produces extreme heat and light and compromises the safety of employees who are exposed to it.

arc flash hoods

An article of loose-fitting arc-rated PPE that covers the head and neck but not the eyes or nose. Arc flash hoods are typically part of an arc flash suit.

arc flash suits

An arc-rated clothing system that covers the entire body except for the hands and feet. Arc flash suits include an arc flash hood.

arc-rated PPE

Safety equipment that is designed to withstand high voltages. Arc-rated PPE reduces the risk of electrocution from arc flashes.

atoms

The smallest distinguishable unit of an element that retains that element's characteristics. Atoms are tiny particles that contain a nucleus and multiple shells.

battery

A device that converts chemical energy into electrical energy. A battery is a portable source of electric current.

bus bar

A grounded metal strip that serves as a common connection between several circuits. Bus bars are found in electrical boxes and distribution panels.

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 can be used to absorb stray electric charges if the machine cannot be connected to a pole embedded in the earth.

chassis ground

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

circuit

A controlled path for electricity. Circuits usually include a source, path, load, and control.

circuit breakers

A safety device that opens and de-energizes a circuit when it detects overcurrent conditions. A circuit breaker often contains a bimetallic strip that bends and trips a switch that opens the circuit.

Class C fire extinguisher

A fire extinguisher that is approved for putting out fires caused by live electrical equipment. Class C fire extinguishers and multi-purpose fire extinguishers are the only extinguishers rated to put out fires caused by faulty wiring and overloaded circuits.

Class E hard hats

A type of insulated hard hat that can withstand up to 20,000 volts. Class E hard hats are one of the two types of hard hats approved for electrical work.

Class G hard hats

A type of insulated hard hat that can withstand up to 2,200 volts. Class G hard hats are one of the two types of hard hats approved for electrical work.

conductive

Able to act as a path for the movement of electricity. Conductive materials include many different types of metals.

conductors

A 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. Current strength is called amperage and is measured in amperes (A), or amps.

de-energized

A state at which all stored energy in a system is removed. A de-energized system does not pose a risk of electric shock.

defibrillator

A machine that is used to reset the rhythm of an irregular heartbeat. A defibrillator can reduce the chance of death when ventricular fibrillation occurs.

dielectric footwear

A type of personal protective equipment worn on the feet that is made from a material that does not conduct electricity. Dielectric footwear may be worn alone or over other footwear.

dielectric strength

A material's ability to withstand stress caused by voltage. Dielectric strength is one of two fundamental insulator properties.

directly proportional

A constant ratio between two values in which one value changes in the same way as the other. For example, if values are directly proportional, it means that when value A increases, value B increases, and if value A decreases, value B decreases.

electric arc

The area in which electricity passes between two conductors that are not in contact. Electric arcs produce extreme heat and light.

electric shock

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

electrical box

A metal cabinet in a building where power from the electrical distribution system enters and is distributed throughout the building. The electrical box connects to every circuit and device in the building.

electrical burns

A burn sustained from handling electrically charged objects. Electrical burns are typically sustained on the hands.

electrically charged

Carrying current. Electrically charged objects pose the risk of electric shock.

electrically neutral

A material or structure that is not electrically charged. Electrically neutral objects are used to absorb stray currents in grounding.

electricity

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

electrocution

Severe injury or death due to electric shock. Electrocution risk can be reduced by the proper use of personal protective equipment.

electrons

A negatively charged particle that orbits the nucleus of an atom. Electrons moving between atoms cause electrical current to flow.

electrostatic discharge

A release of static electricity that occurs when two charged objects come into contact. Electrostatic discharge is a major concern when working with electronics as it can harm equipment and technicians.

extension cords

A type of flexible wiring that is used to connect the power cable of a device to a power source that is not close by. Extension cords are not recommended for long-term use because they increase the risk of electrical fire.

face shields

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

fuses

A safety device that opens a circuit when it detects excess current. A typical fuse has a component that melts to open the circuit.

grips

The textured part of a tool that the user holds onto. Grips on insulated tools are made of rubber or another non-conductive material.

ground

A source of zero electrical potential, such as the earth or another large conducting body. A ground absorbs electrical currents.

ground fault circuit interrupter

GFCI. A protective device that disables power to a circuit if a dangerous fault current occurs. Ground fault circuit interrupters should be used whenever there is a chance for electricity to come into contact with water.

ground wires

A wire in an electrical system that provides a low-resistance path to ground for stray current. Ground wires are usually bare copper or covered with green insulation.

grounded conductors

The wire through which electricity travels from a load back to the source. Grounded conductors, also known as neutral wires or return conductors, are typically covered with white insulation.

grounding

A means of providing a safe path for electricity in case it strays from its intended path. Grounding directs current to a neutral source, such as the earth.

grounding conductors

A wire in an electrical system that provides a low-resistance path to ground for stray current. Grounding conductors are usually bare copper or covered with green insulation.

grounding rod

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

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, chemical exposure, and electric shock, can affect a person externally and internally.

hot wires

The wire through which electricity travels from the source to the load. Hot wires are usually covered with black insulation, but red insulation is sometimes used.

insulated floor mats

A safety device that employees stand on to prevent electric shock. Insulated floor mats prevent employees from being a path to the ground.

Insulated tools

A device like a screwdriver, hammer, or wrench that has a rubber or plastic handle. Insulated tools protect the user from electric shock.

insulators

A material or element that has little electrical conductivity and high resistance to electrical charges. Most insulators are plastics and ceramics.

inversely proportional

A relationship in which one number either increases as another decreases or decreases as another increases. Inversely proportional is the opposite of directly proportional.

leather gloves

A type of personal protective equipment that is worn by itself or over rubber-coated gloves. Leather gloves provide insulation against heat and electricity.

live circuit

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

load

A component in a circuit that converts electricity into light, heat, or mechanical motion. Loads include light bulbs, appliances, and machines.

lockout device

A safety device that holds a switch in the 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 require maintenance. Lockout/tagout is a method of protecting employees from accidental machine startup.

milliamperes

mA. A unit used to measure low currents. One milliampere is equal to one thousandth of an ampere.

multi-purpose fire extinguisher

A fire extinguisher that is approved for putting out several different types of fires. Multi-purpose fire extinguishers, also called ABC fire extinguishers, are capable of putting out electrical fires.

National Electrical Code

NEC®. The standard for minimum safe electrical installations in the United States. 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 created and maintains the National Electrical Code®.

neutral wires

The wire through which electricity travels from a load back to the source. Neutral wires, also known as grounded conductors or return conductors, are typically covered with white insulation.

NIOSH

National Institute for Occupational Safety and Health. A government agency that is responsible for conducting research and making recommendations for the prevention of work-related injury and illness. NIOSH works closely with the Occupational Safety and Health Administration (OSHA) to protect employees in the U.S.

non-conductive

Unable to act as a path for the movement of electricity. Non-conductive materials have high resistance.

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 impede or obstruct current flow.

Ohm's Law

The universal truth that describes the relationships between voltage, amperage, and resistance. Ohm’s Law states that one volt equals one amp times one ohm.

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.

path

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

personal protective equipment

PPE. Any clothing or device used to prevent injury or illness. Common personal protective equipment worn during electrical work includes safety glasses, rubber-soled footwear, and gloves.

plastic

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

power source

A device that provides electricity to a circuit. Power sources include batteries and generators.

PPE

Personal protective equipment. Any clothing or device used to prevent injury or illness. Common PPE worn during electrical work includes safety glasses, rubber-soled footwear, and gloves.

radiation burns

Damage to the skin or eyes caused by radiation. Radiation burns can be caused by the ultraviolet radiation produced by an arc flash.

resistance

R. The opposition to current flow. Resistance is measured in ohms (Ω).

respiratory paralysis

The loss or impairment of the use of the respiratory organs. Respiratory paralysis can result from electric shock and prevents a person from breathing.

return conductors

The wire through which electricity travels from a load back to the source. Return conductors, also known as neutral wires or grounded conductors, are typically covered with white insulation.

rubber

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

rubber-coated gloves

A type of personal protective equipment worn on the hands that has a non-conductive material on the palms and fingers. Rubber-coated gloves insulate the wearer’s hands from electricity.

rubber-soled footwear

Boots or shoes that have a non-conductive material on the bottom where they contact the floor. Rubber-soled footwear protects against electric shock.

safety glasses

Protective eyewear that shields the eyes from debris and sparks. Safety glasses that are used around electrical hazards must be made of a non-conductive material.

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 label 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 conductive device within a circuit to which other components can be attached. Terminals have a negative or positive charge.

thermal contact burns

A burn sustained from exposure to fire or extreme heat. Thermal contact burns can result from overheated electrical components or arc exposure.

three-stage safety model

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

ultraviolet radiation

UV radiation. Energy transmitted as a wavelength of light that is below, or shorter than, violet on the light spectrum. Ultraviolet radiation can be caused by an electric arc and can burn the skin and eyes.

UV radiation

Ultraviolet radiation. Energy transmitted as a wavelength of light that is below, or shorter than, violet on the light spectrum. Ultraviolet radiation can be caused by an electric arc and can burn the skin and eyes.

variables

A characteristic that changes according to the situation. Electrical variables include amperage, voltage, and resistance.

ventricular fibrillation

An irregular heart rhythm characterized by rapid and ineffective heartbeats. Ventricular fibrillation can be caused by electric shock and may lead to death within minutes.

voltage

E. The electrical pressure or force that causes current to flow in a circuit. Voltage is measured in volts (V).

volts

V. A unit of measurement for electromotive force or pressure. Volts are used to measure voltage.