Avoiding Electrocution Hazards
What properties does a conductor have?
a substance that allows electrical current flow.
If an individual receives _____ milliamps of current, a shock is felt but it is not painful, and that person may be injured from a fall due to involuntary movements.
5 milliamps
a person will lose control of his/her muscles in the range from
6 to 30 milliamps.
A faint tingling sensation can be felt when the body experiences a current of ______ milliamp(s).
1
Nerve damage and death are likely to occur if the body receives a current of ____ to ___ milliamps.
1,000 to 4,300 milliamps.
True or false: in order to keep yourself and your co-workers safe, you must be able to recognize electrical hazards.
true
BESAFE- "A"
An arc flash is the sudden release of electrical energy through the air that gives off thermal energy, or heat, and bright, intense light that can cause burns. Temperatures have been recorded as high as 35,000 °F
electrical circuit
An electric circuit is a closed loop in which electrons move from a power source, through a conductor, and back to the power source
What are circuit protection devices and how do they work?
Circuit protection devices limit or stop the flow of current automatically in the event of a ground fault, overload, or short circuit in the wiring system. Well-known examples of these devices are fuses, circuit breakers, ground-fault circuit interrupters, and arc-fault circuit interrupters
Conductor
Conductor is defined as a material through which an electrical current easily moves. A conductor material allows a current flow.
Deenergized
Deenergized means that all energy sources to circuits and equipment has been turned off and any stored energy has been depleted from the system.
Current
Electrical current is defined as the movement of electrical charge. Current is measured in amps.
Third-degree burns
penetration of the entire thickness of the skin (epidermis, dermis, and hypodermis), and tissues (hair, nerves, and sweat glands) are often permanently damaged or destroyed.
Electricity
The word electricity is used to describe current flow through a conductor in a closed circuit.
Energized
also called live, or hot, means that a voltage is present and it can cause an electrical current. Any time an electrical current is present, there is a risk of being shocked.
AC
alternating current (AC), provided by electric generators that supply current to an electric grid shared by everyone in the country
What special training do employees need?
deenergize the equipment use lockout/tagout procedures to ensure that the equipment remains deenergized use insulating protective equipment maintain a safe distance from energized parts
DC
direct-current (DC) provided by a battery.
Electricity cannot flow through the air. Is this true or false?
false
Second-degree burns
first two layers of skin, the epidermis and dermis
People can become part of a _______. When a person becomes part of an electrical______, that person can be shocked.
flow
Amperage
referred to as amps or milliamps, indicates the strength of an electrical current. Amperage is measured in units of Amperes, often called Amps or milliamps. (One amp is equal to 1,000 milliamps).
Electricity can flow through tissues and fluids in the human body. Is this true or false?
true
First-degree burns
the top layer of skin, or the epidermis
_____milliamps, death is probable, severe burns, and cardiac arrest occurs.
10, 000
Conductors
A few examples of conductors include: metals, body tissues, body fluids, and water.
Insulators
A few examples of insulators include; rubber, plastic, wood, cloth, glass, and the earth. Air, normally an insulator, can become a conductor, as occurs during an arc flash or lightning strike.
Under which of the following circumstances would a person be shocked?
Becoming part of an electrical circuit
An electric shock can result in anything from a slight tingling sensation to immediate cardiac arrest. The severity depends on the amount of current flowing through the body, the current's path through the body, the length of time the body remains in the circuit, and the current's _______.
Frequency
What is the name of the device that sense the current flowing, tripping the circuit, and cutting off the electricity?
Ground Fault Circuit Interrupter (GFCI)
What is grounding and what protection does it offer?
Grounding" a tool or electrical system means intentionally creating a low-resistance path that connects to the earth. This prevents the buildup of voltages that could cause an electrical accident.
Insulator
Insulator, or insulation, is a material that does not easily conduct electricity. An insulator material resists current flow.
What protection does insulation provide?
Insulators such as glass, mica, rubber, or plastic used to coat metals and other conductors help stop or reduce the flow of electrical current. This helps prevent shock, fires, and short circuits. Insulation is found on flexible wiring, electrical cords, and various medical devices used during surgery or patient treatment.
A Ground Fault Circuit Interrupter (GFCI) works by comparing the amount of current going to and returning from equipment along the circuit conductors. When the amount going differs from the amount returning by approximately 5 milliamps, what does the GFCI do
Interrupts the current
How can you prevent an accidental or unexpected equipment startup?
Proper lockout/tagout procedures protect you from the dangers of the accidental or unexpected startup of electrical equipment. These procedures ensure that electrical equipment is deenergized before it is repaired or inspected and protects you against electrocution or shock.
Flow of Electricity
Pure water is a poor conductor. But small amounts of impurities in water like salt, or chlorine, help water become a better conductor. Dry wood, for example, generally slows or stops the flow of electricity. But when saturated with water, wood turns into a conductor.
Which of these is not required for current to flow through a conductor?
Something that has air molecules
Which factor increases the risk of injury if a person is shocked?
Sweat
GFCI
The GFCI will not protect you from line contact hazards (i.e. a person holding two "hot" wires, a hot and a neutral wire in each hand, or contacting an overhead power line). However, it protects against the most common form of electrical shock hazard, the ground-fault. It also protects against fires, overheating, and destruction of wire insulation.
After a strong storm, a worker does not realize that a power transmission line has fallen on the car and is electrocuted while opening the car door.
contact with an overhead power line.
An electrical shock happens when electric _______ enters the body at one point and leaves through another.
current
OSHA expects employers to lockout/tagout ___________ controls while working on energized or deenergized equipment or circuits.
deactivated controls
Voltage
is a measure of electrical force. Voltage is measured in volts.
Shocking Current
is the electrical current that passes through a part of the body. In that case, we usually say that someone is shocked by electricity.
How can you protect yourself against metal parts that become energized?
is to establish a low-resistance path from the device's metallic case to the ground. The electrical equipment should be electrically grounded
Employers should attach tags to identify equipment or circuits being worked on while any worker is exposed to contact with ____________ parts.
live parts.
energized source
the bare wire is in contact with the metal frame - also a conductor - and the worker is touching it whilst standing on a wet surface