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Electrical Safety Subpart K
Disclaimer The information presented in this presentation has been compiled from sources believed to be reliable and is intended to be a tool to assist and guide you in building your own presentation. This program may not address all the hazardous conditions or unsafe acts that may exist. For that reason, SPIN cautions users to confirm accuracy and compliance with the latest standards and best practices. Local, State/Provincial and Federal regulations take precedence over this material. Implementation of any practices suggested by this program is at your sole discretion, and SPIN will have no liability to any party for any damages including, but not limited to, direct, indirect, special or consequential damages, arising out of or in connection with the information provided or its use.
Purpose of Training • To increase employee awareness of electrical hazards on the jobsite • To control or eliminate employee exposure to electrical hazards • To ensure that everyone understands the AEGCP and the use of GFCI’s • To help meet OSHA compliance
Hazards of Electricity • Shock • Fibrillation • 50-100mA of current to cause fibrillation • Damage to tissue • external burns & internal tissue & organ damage • entry & exit wounds • Muscle Contractions • unable to release • causes longer period of contact
Electrocution • Current and Voltage • Path • Time
Electrocution? • Body temperature rises to 138° F • Tissues are baked like well done beef • Physical reactions include: • heaving chest • foaming mouth • bloody sweat • burning hair & skin • release of feces • eyeballs pop out
Fatal Assumptions: • 120Volts can’t hurt me • DC can’t hurt me • Overhead power lines are insulated • I can’t get hurt if I don’t touch the wire • The more I get shocked the more immune I become • Circuit breakers are designed for personnel safety • Joe Bob knows I’m working on this so I’m O.K.
Fatalities: • Failure to lockout piece of equipment • Power tools shorting out • contacted overhead power lines
Three Levels of Protection: • Engineering danger out of the job • Safe work practices • Personal protective equipment (PPE)
Typical Construction Hazards • Overhead lines • Buried lines • Sharp edges on metal material (studs) • Cords that are damaged in anyway • Safe clearances around electrical equipment • Damaged tools or receptacles • Wet weather conditions
Typical Construction Hazards • Temporary wiring • High voltage lines • crane operations • metal ladders • tight workspace • Improper or nonexistent grounding • Non-existent or non-functional GFCI’s • Improper or non-existent security
Common Citations • No GCFI or AEGCP • Tools have no ground • Lack of training when near power lines • Equipment not approved for classified locations • Guarding of live parts • Flexible cord strain relief
OSHA Gives Two Options: • Ground Fault Circuit Interrupters • GFCI • Assured Equipment Grounding Conductor Program • AEGCP
Ground Fault Circuit Interrupters • Intended to quickly interrupt the circuit in the event of a ground fault, to prevent electrocution. • GFCI will break the circuit when a leakage of 5mA or more is occurring • usually within 1/40 of a second • GFCI requirements pertain only to temporary wiring on construction sites • exception: kitchens & other wet area’s • Must provide approved GFCI’s on all 120v, single phase, 15 & 20A receptacle outlets Note: GFCI does not prevent shock!
How the GFCI protects people (By opening the circuit when current flows through a ground-fault path)
Assured Electrical Grounding Conductor Program • All cord sets & receptacles which are not part of the permanent wiring of the building or structure shall be tested and marked. Jan.-Mar. White April-June Green July-Sept. Red Oct.-Dec. Orange Repair Brown
When to test? • Before first use • After any repairs • Before equipment is returned to service • Before equipment is used after any incident, where damage may be suspected. • Every quarter
How to test? Plugs in to show if terminals are correctly connected to ground, and if wire is continuous (without breaks) Checks if ground is continuous from metal frame (a) through cord to 3rd prong (b). Also touch tester contact to (c) then (d) prongs to detect possible ground fault
Recording Test Results: • The test preformed shall be recorded to identify each receptacle, cord set and plug-connected equipment that passed. • This record shall be kept by: • logs • color coding • other effective means
Temporary Power Hook-Up • All temporary outlets rated at 120 volt, single phase, 15 & 20 amps must have GFCI’s and established AEGCP. • All extension cords will be of the three conductor wire type • All temporary lights must be guarded to protect against accidental contact or breakage • All temporary lights must be on separate circuits from tool circuits
Hand and Power Tools • Inspect tools for wear or defects • Never modify tools • Inspect for frayed insulation or loose connection • Make sure tools are clean and dry • Do not carry, store or hang up by power cord • Never remove grounding post • Do not overload wall plugs or extension cords • Stop using tools immediately if they begin to smoke, spark or shock
The drill was not double insulated and the ground prong was missing Three citations issued: GFCI’s or AEGCP Inspect electrical tools use equipment that provides a permanent and continuous path from circuits or equipment to ground Accident Review:
Portable Extension Cords • Inspect portable extension cords daily: • Is the tool rated for the job your doing • Are the cord’s plug & receptacle designed to be used together • Does the cord have loose parts, deformed & missing pins or damage to outer insulation? • Does the cord have a working GFCI? • Ensure that cords are protected from pinch points & sharp edges Note: Never staple a cord, or raise and lower equipment with the cord.
Overload • Beware of overload • More than two plugs per double outlet is overloaded • Never overload any outlet for any reason
Housekeeping • Keep cords out of walkways and roadways • If not possible, cords must be protected from vehicle traffic • Keep cords clean & dry • Make sure hands are dry before unplugging cords and equipment
Flammable Dust and Vapors • Combustible dust, flammable fumes or excess oxygen can be ignited by a spark • Use ventilation to lower the concentration of atmospheric hazards in your work area. Note: 60% of all industrial fires are caused by poor connections and faulty outlets.
For Electrical Fires • 911 • Do not touch burning object • Do not use water • use CO or ABC extinguisher • Unplug or turn off the current if it can be done safely • Stay clear of the area and wait for the professionals
Bonding There is no voltage between two conductive objects that are bonded together
Approach distances for Qualified employees: • Qualified person: specifically trained in the hazards of working on energized parts and equipment. 300V & less…………………………..….Avoid contact Over 300V, not over 750V………………1 ft. 0 in. Over 750V, not over 2kV………………..1 ft. 6 in. Over 2kV, not over 15kV………………..2 ft. 0 in. Over 15kV, not over 37kV………………3 ft. 0 in. Over 37kV, not over 87.5kV…………….3 ft. 6 in. Over 87.5, not over 121kV………………4 ft. 0 in. Over 121kV, not over 140kV……………4 ft. 6 in.
Approach distances for unqualified employees: • Neither you nor anything you touch can get within 10 feet of an over head line carrying up to 50kV. • Add 4 inches of clearance for every 10kV over 50kV.
Electrical Arc: • Temperature can reach 35,000º F • 4 times hotter than the sun • similar to nuclear weapons • You can be killed at up to 20 feet from a high energy arc • and receive severe burns as far as 40 feet away • Over half of all electrical injuries involve burns from arcs
High Voltage Lines • 1 out of 3 injuries cause by high voltage lines results in death! • Reminders for operators: • Make sure that no part of your equipment can come within 10 feet of high voltage lines. • Never attempt to raise or move high voltage lines • If equipment touches a high voltage line back away or lower boom to break contact • Generally safe to stay in the cab • Dismount by jumping clear, and shuffling Note: Never touch any part of the equipment and ground at the same time
Employee received no training on the hazard nor any specific instruction Two serious citations were issued: Lack of training Not permit employees to work near any electrical power circuit without de-energizing Accident Review:
Unloading a 40 foot telephone pole from pipe rack Four serious citations issued Training on the hazards Do not operate equipment within approach distances Did not maintain proper clearances Determine existing conditions Accident Review
First Aid • Do not touch the victim • 911 • Turn off power • Use non-conductive object to push person away from the electrical source • Administer rescue breathing, if breathing has stopped • Administer CPR if heart has stopped • Cover electrical burns • Reassure & calm victim until help arrives
Report All Near Misses • Often symptoms are delayed and the person may need medical attention. • The Safety Department must be notified any time an employee has an accident involving an electrical shock. Note: the purpose of the investigation, is to prevent the reoccurrence
Lock Out-Tag-out The Control of Hazardous Energy
Authorized & Affected: Authorized: employees will actually be performing the lock-out tag-out procedures, and must be trained to understand the program Affected: employees working in the area, must understand what lock-out tag-out is and how it effects them.
When Should You Lock-Out • Clearing blocked or jammed mechanisms • Maintenance or repair work on equipment with moving parts • Certain confined space entries • Repairs or installation on electrical circuits
Sequence of Lock-out or Tag-out Procedure • Notify all affected employees • Shut down machine or equipment • Isolate energy source springs air/ gas radioactive hydraulic water pressure electrical steam chemical mechanical centrifugal • Lock-out & tag-out energy isolating device • After ensuring that no one is exposed, check to be sure energy source is disconnected Caution: Return operating controls back to neutral or off position
Accident Review • Employee was attempting to correct an electrical problem with two non-operational lights • Two citations issued: • No Lock-out / Tag-out program • Circuit not de-energized or locked / tagged -out
Procedure Involving More Than One Person • Each person shall have his own lock • Each lock shall be secured, so that all locks must be removed before equipment can be re-energized • The lock may only be removed by the person who placed it there
Maintenance and Repair of Equipment in the Field • Any vehicle determined to be unsafe shall be tagged out of service and may not be operated • Mechanic will notify supervisor & the operator and obtain approval to service equipment • If equipment is in operation perform normal shut down procedures • Person performing work will then place lock-out or tag-out device in position • Key shall be removed from equipment & placed in pocket of person performing work
Removal of the Tags and Locks: • Under normal conditions each person will remove their own tags & locks • If the signer of the tag is not available or has left the site, a supervisor meeting the following may remove the tag or lock: • Supervisor from same dept. • Supervisor must talk to signer on condition of equipment • Supervisor must have sufficient knowledge of work being performed • Supervisor must be able to exercise proper judgement
Re-energizing Electrical Systems • Inspect the entire work area • tools have been removed • guards are in place • Insure equipment is safe to operate • Warn co-workers • no one is exposed • Notify everyone affected • Remove locks & re-energize
Remember: • Notify all affected employees • Shut down machine or equipment • Isolate energy source • Lock out & tag-out energy isolating device • Check to be sure that energy source is disconnected • Return operating controls back to neutral or off position
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