1. Electrical Safety

2. Training Objectives Describe how electricity works
Describe how shocks occur
Describe how electrical current affects the body
Describe the most common ways individuals are injured using electricity
Provide solutions to avoid being injured while using electricity
Lockout/Tagout

3. Responsibility Employees Supervisor
When operating electrical equipment employees will be familiar with the manufacturer instructions.
Employees must tag defective equipment out and report it to their supervisor.
Employees will check electrical cords prior to use.
Supervisor
Supervisor will make a determination on the appropriate avenue for replacement or repair of defective equipment.

4. How Electricity Works Example: A Garden Hose Flow of Water
To Low Pressure
Water Moves from High Pressure
The same thing occurs in an Electrical Wire
Flow of Current
Current Moves from High Voltage
To Low Voltage

5. Electrical Shocks
Electricity travels in closed circuits, normally through a conductor
Shock results when the body becomes part of the electrical circuit
Current enters the body at one point and leaves at another
Note: Ground circuits provide a path for stray current to pass directly to the ground, and greatly reduce the amount of current passing through the body of a person in contact with a tool or machine that has an electrical short. Properly installed, the grounding conductor provides protection from electric shock.

6. Shock and the Human Body
The effects of shock can depend upon
The type of circuit
Voltage resistance
Current
Pathway through the body
Duration of the contact
Effects can range from a tingle to cardiac arrest.

7. How Electrical Current Affects the Body
(Amps)
Human Reaction
0.001
Perception level. Just a faint tingle.
0.005
Slight shock felt; not painful but disturbing. Average individual can let go.
(Women)
Painful shock, muscular control is lost.
(Men)
This is called the freezing current or "let-go" range.
Extreme pain, respiratory arrest, severe muscular contractions.
Ventricular fibrillation. 10
Cardiac arrest, severe burns and probable death.
Note: some smaller microwave ovens use 10.0 Amps (10,000 milliamps) and common florescent lights use 1 Amp (1,000 milliamps)

8. Burns
The most common shock-related injury is a burn. Burns suffered in electrical incidents may be one or more of the following three types:
Electrical Burns cause tissue damage, and are the result of heat generated by the flow of electric current through the body. Electrical burns are one of the most serious injuries you can receive and need to receive immediate medical attention.
High temperatures near the body produced by an electric arc or explosion cause Arc or Flash Burns (also need prompt medical attention)
Thermal Contact Burns occur when skin comes in contact with overheated electric equipment, or when clothing is ignited in an electrical incident.

9. Internal Injuries
Our bodies use small electrical currents to transmit signals through the nervous system and contract muscles,
Extra electrical current flowing through the body can cause serious damage.
Medical problems can include internal bleeding, tissue destruction,
and nerve or muscle damage.
Internal injuries may not be immediately apparent to the victim or observers; however, left untreated, they can result in death

10. Involuntary Muscle Contraction
Muscles violently contract when stimulated by excessive amounts of electricity.
These involuntary contractions can damage muscles, tendons, and ligaments, and may even cause broken bones.
If the victim is holding an electrocuting object, hand muscles may contract, making it impossible to drop the object.
Note: injury or death may result from a fall due to muscle contractions.

11. Water and Conduction
Conductors- Substances with relatively little resistance to the flow of electrical current (e.g., metals).
Water- influences the conductive properties of some materials
Dry wood is a poor conductor
Wood saturated with water becomes a ready conductor
Use extreme caution when working with electricity where there is water in the environment or on the skin.

12. Human Skin & Resistance
Dry Conditions Human Skin is Resistant
Current = Volts/Ohms = 120/100,000 = 1mA (0.001A)
Barely perceptible level of current
Wet Conditions Skin’s Resistance drops dramatically
Current = Volts/Ohms = 120/1,000 = 120mA (0.12A)
-Sufficient current to cause ventricular fibrillation
A low voltage electrocution becomes much more hazardous in a wet condition
High voltage electrical energy greatly reduces the body's resistance by quickly breaking down human skin. Once the skin is punctured, the lowered resistance results in massive current flow.

13. Low Voltage = Hazardous
Muscular contraction caused by stimulation does not allow a victim to free himself from a circuit
The degree of injury increases with the length of time the bdy is in the circuit.
Thus even relatively low voltages can be extremely dangerous.
LOW VOLTAGE
DOES NOT IMPLY
LOW HAZARD!
An exposure of 100mA for 3 seconds can cause the same amount of damage as an exposure of 900mA for .03 seconds

14. Ground-Faults (The Most Common Form of Electrical Shock)
A ground-fault occurs when current flowing to the load (drill, saw, etc.) does not return by the prescribed route.
In a simple 120 volt circuit, current travels through the black (ungrounded) wire to the load and returns to the source through the white (grounded) wire. If some or all of the current does not travel back through the white wire then it has gone somewhere else, usually to ground.
A person’s body can act as the path to ground when a fault occurs.

15. Ground-Fault Protection
The 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 milliamperes, the GFCI interrupts the current within as little as 1/40 of a second.
Note: A 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.

16. Ground-Fault Protection
Use ground-fault circuit interrupters (GFCIs) on all 120-volt, single-phase, 15- and 20-ampere receptacles that will be used to supply temporary power (i.e. hand tools and other portable equipment).
-Portable GFCIs, like this one, are available for situations where GFCI protection is not otherwise provided-
Important - Plug this end directly into the electrical source, not another flexible cord.
Follow manufacturers' recommended testing procedure to insure GFCIs are working correctly.

17. Grounding - How Do I Avoid Hazards
Ground all power supply systems, electrical circuits, and electrical equipment
Do not remove ground pins/prongs from cord- and plug-connected equipment or extension cords
Use double-insulated tools
Ground all exposed metal parts of equipment

18. Overhead Lines
When mechanical equipment is being operated near over-head lines, employees standing on the ground may not contact the equipment unless it is located so that the required clearance cannot be violated even at the maximum reach of the equipment.
These employees and their mechanical equipment must stay at least 10 feet ( 3.05 meters) away from the overhead power lines.

19. Overhead Lines
Employees, whose occupations require them to work directly with electricity, must use the personal protective equipment required for the jobs they perform.
This equipment may consist of rubber insulating gloves, hoods, sleeves, matting, blankets, line hose, and industrial protective helmets.

20. Overhead Lines
Perhaps the single most successful defense against electrical accidents is the continuous exercising of good judgment or common sense.
All employees should be thoroughly familiar with the safety procedures for their particular jobs. When work is performed on electrical equipment, for example, some basic procedure are:
Have the equipment deenergized.
Ensure that the equipment remains deenergized by using a lockout/tagout procedure.
Use insulating protective equipment.
Keep a safe distance from energized sources.

21. Boom type units shall be grounded and the following
clearances shall be maintained or the line de-energized:
Power Line Voltage Phase to Phase (KV)
Minimum Safe Clearance ( Feet)
50 or below 10
Above 50 to 200 15
Above 200 to 350 20
Above 350 to 500 25
Above 500 to 1,000 45

22. Using Equipment in a Manner Not Prescribed By The Manufacturer
If electrical equipment is used in ways for which it is not designed, you can no longer depend on safety features built in by the manufacturer. This may damage property and cause employee injuries or worse
Note: Junction boxes such as this one must be mounted properly.
Shock, fire, loss of life and property?

23. Common Examples of Equipment Used in A Manner Not Prescribed
Using multi-receptacle boxes designed to be mounted by fitting them with a power cord and placing them on the floor.
Using equipment outdoors that is labeled for use only in dry, indoor locations.
Using circuit breakers or fuses with the wrong rating for over-current protection, e.g. using a 30-amp breaker in a system with 15- or 20-amp receptacles (protection is lost because it will not trip when the system's load has been exceeded).
Using modified cords or tools, e.g., removing face plates, insulation, etc.
Using cords or tools with worn insulation or exposed wires.
REMEMBER - ONLY USE EQUIPMENT IN A MANNER PRESCRIBED BY THE MANUFACTURER

24. Flexible Cords Not Used Properly
The following cords are improperly wired directly to the electrical circuit, are not protected by a GFCI, and are two-wire cords that are not grounded and not rated for hard- or extra-hard service.
Temporary (flexible wiring) must not be used in place of permanent wiring. Multioutlet surge protection such as this can be used to supply power to equipment that needs surge protection, but not used to provide more outlets due to the lack of permanent wiring.
Note: a common OSHA violation.

25. Remember Visually inspect all electrical equipment before use.
Remove any equipment with frayed cords, missing ground prongs, cracked tool casings, etc. from service.
Apply a warning tag to any defective tool and do not use it until it has been properly repaired.

26. Care of Cords & Equipment
Electrical panel boxes must be secured and problems reported immediately.
Junction boxes, outlets, receptacles, and switches must be closed and problems reported.

27. Care of Cords & Equipment
Electric panels must be kept clear of any obstructions at all times.
Storage is not allowed in electrical vault or service panel rooms. Find another place for storage of materials, products, etc.

28. Care of Cords & Equipment
Electrical within two (2) feet of any water source must have GFCI protection. Covers must be in place at all times.
No flammable chemicals or liquids can be stored near electrical or in electrical service rooms.

29. Lockout/Tagout What is hazardous energy?
Energy sources including electrical, mechanical, hydraulic, pneumatic, chemical, thermal or other sources in machines and equipment can be hazardous to workers. During the servicing and maintenance of machines and equipment, the unexpected startup or release of stored energy could cause injury to employees.

30. Lockout/Tagout What are the harmful effects of hazardous energy?
Workers servicing or maintaining machines or equipment may be seriously injured or killed if hazardous energy is not properly controlled. Injuries resulting from the failure to control hazardous energy during maintenance activities can be serious or fatal! Injuries may include electrocution, burns, crushing, cutting, lacerating, amputating, or fracturing body parts, and others.
A steam valve is automatically turned on burning workers who are repairing a downstream connection in the piping.
A jammed conveyor system suddenly releases crushing a worker who is trying to clear the jam.
Internal wiring on a piece of factory equipment electrically shorts shocking employee who is repairing the equipment.
Craft workers, electricians, machine operators, and laborers are among the 3 million workers who service equipment routinely and face the greatest risk of injury. Workers injured on the job from exposure to hazardous energy lose an average of 24 workdays for recuperation.

31. Lockout/Tagout What can be done to control hazardous energy?
Failure to control hazardous energy accounts for nearly 10 percent of the serious accidents in many industries. Proper lockout/tagout (LOTO) practices and procedures safeguard workers from the release of hazardous energy. OSHA's Lockout/Tagout fact sheet (PDF*) describes the practices and procedures necessary to disable machinery or equipment to prevent the release of hazardous energy. The OSHA standard for The Control of Hazardous Energy (Lockout/Tagout) (29 CFR ) for general industry outlines measures for controlling different types of hazardous energy. The LOTO standard establishes the employer's responsibility to protect workers from hazardous energy. Employers are also required to train each worker to ensure that they know, understand, and are able to follow the applicable provisions of the hazardous energy control procedures:

32. Lockout/Tagout
Proper lockout/tagout (LOTO) practices and procedures safeguard workers from the release of hazardous energy. The OSHA standard for The Control of Hazardous Energy (Lockout/Tagout) (29 CFR ) for general industry, outlines specific action and procedures for addressing and controlling hazardous energy during servicing and maintenance of machines and equipment. Employers are also required to train each worker to ensure that they know, understand, and are able to follow the applicable provisions of the hazardous energy control procedures. Workers must be trained in the purpose and function of the energy control program and have the knowledge and skills required for the safe application, usage and removal of the energy control devices.
All employees who work in the area where the energy control procedure(s) are utilized need to be instructed in the purpose and use of the energy control procedure(s) and about the prohibition against attempting to restart or reenergize machines or equipment that is locked or tagged out.
All employees who are authorized to lockout machines or equipment and perform the service and maintenance operations need to be trained in recognition of applicable hazardous energy sources in the workplace, the type and magnitude of energy found in the workplace, and the means and methods of isolating and/or controlling the energy.
Specific procedures and limitations relating to tagout systems where they are allowed.
Retraining of all employees to maintain proficiency or introduce new or changed control methods.

33. Summary
Employees operating electrical equipment shall be thoroughly familiar with the operating instructions furnished by the manufacturer. If the equipment does not function properly after instructions have been followed, defective equipment must be tagged out of service and the condition of the equipment reported to the supervisor. The supervisor will make a determination on the appropriate avenue of replacement or repair. Employees shall inspect the condition of the equipment and electrical cords prior to use.

34. References OSHA Electrical Standards
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OSHA Lockout/Tagout Fact Sheet
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