Safety & Health Consultation Electrical in General Industry

N UMBER OF S ERIOUS V IOLATIONS – FY CFR 1910 S UBPARTS E LECTRICAL [ – 399] 2 P ROPER I NSTALLATION & U SE OF E QUIPMENT G ROUNDING P ERMANENT AND E FFECTIVE F LEXIBLE C ORD S TRAIN R ELIEF SUBPART S F LEXIBLE C ORDS U SED AS F IXED W IRING P ULL / JUNCTION B OX C OVERS

Safety & Health Consultation Electrical Terminology Current – the movement of electrical charge Resistance – opposition to current flow Voltage – a measure of electrical force Conductors – substances, such as metals, that have little resistance to electricity Insulators – substances, such as wood, rubber, glass, and bakelite, that have high resistance to electricity Grounding – a conductive connection to the earth which acts as a protective measure

Electrical Utilization Systems Electrical installations and utilization equipment installed or used within or on buildings, structures and other premises: –Yards –Carnivals –Parking and other lots –Mobile homes –Recreational vehicles –Industrial substations –Conductors that connect the installations to a supply of electricity –Other outside conductors on the premises Safety & Health Consultation (a)

Safety & Health Consultation Electrical Hazards What’s the first thing that comes to mind? Shock Burns Fire Explosions Direct: Electrocution Reaction: Falls Arc Blast / Arc Flash

Safety & Health Consultation Shock & Electrocution Levels 1/1000 ampere – Perception level 1/100 ampere – Muscular contraction 1/10 ampere – Electrocution Overcurrent devices Does NOT trip until at least 15 amperes

Safety & Health Consultation Question??? Are over current devices used to protect people? No, they protect equipment and property

Safety & Health Consultation Electrical Protective Devices These devices shut off electricity flow in the event of an overload or ground-fault in the circuit Include fuses, circuit breakers, and ground-fault circuit-interrupters (GFCI’s) Fuses and circuit breakers are overcurrent devices –When there is too much current: Fuses melt Circuit breakers trip open

Safety & Health Consultation Electrical Shock Received when current passes through the body Severity of the shock depends on: –Path of current through the body –Amount of current flowing through the body –Length of time the body is in the circuit LOW VOLTAGE DOES NOT MEAN LOW HAZARD

Safety & Health Consultation Dangers of Electrical Shock Currents greater than 75 mA* can cause ventricular fibrillation (rapid, ineffective heartbeat) Will cause death in a few minutes unless a defibrillator is used 75 mA is not much current – a small power drill uses 30 times as much * mA = milliampere = 1/1,000 of an ampere Defibrillator in use

Safety & Health Consultation How is an electrical shock received? When two wires have different potential differences (voltages), current will flow if they are connected together –In most household wiring, the black wires are at 110 volts relative to ground –The white wires are at zero volts because they are connected to ground If you come into contact with an energized (live) black wire, and you are also in contact with the white grounded wire, current will pass through your body and YOU WILL RECEIVE A SHOCK

Safety & Health Consultation How is an electrical shock received? If you are in contact with an energized wire or any energized electrical component, and also with any grounded object, YOU WILL RECEIVE A SHOCK You can even receive a shock when you are not in contact with a ground –If you contact both wires of a 240-volt cable, YOU WILL RECEIVE A SHOCK and possibly be electrocuted

Safety & Health Consultation Electrical Hazards Remember, if it’s an electrocution, it’s a FATALITY!

Safety & Health Consultation Falls Electric shock can also cause indirect or secondary injuries Workers in elevated locations who experience a shock can fall, resulting in serious injury or death

Safety & Health Consultation Electrical Burns Most common shock-related, nonfatal injury Occurs when you touch electrical wiring or equipment that is improperly used or maintained Typically occurs on the hands Very serious injury that needs immediate attention

Safety & Health Consultation Fires

Safety & Health Consultation A hazard exists when a conductor is too small to safely carry the current Example: using a portable tool with an extension cord that has a wire too small for the tool –The tool will draw more current than the cord can handle, causing overheating and a possible fire without tripping the circuit breaker –The circuit breaker could be the right size for the circuit but not for the smaller-wire extension cord Inadequate Wiring Hazards

Safety & Health Consultation Note: The larger the gauge number, the smaller the wire.

Safety & Health Consultation Overload Hazards If too many devices are plugged into a circuit, the current will heat the wires to a very high temperature, which may cause a fire If the wire insulation melts, arcing may occur and cause a fire in the area where the overload exists, even inside a wall

Safety & Health Consultation Explosions Arc Blast/Arc Flash

Safety & Health Consultation “I can work it live because I’m Qualified!”

Safety & Health Consultation “The standards require that all work shall be done de-energized!” NFPA 70E

Safety & Health Consultation Explosions 80% of electrically related accidents, incidents, and fatalities among Qualified Workers Caused by Arc Blast/Arc Flash

Safety & Health Consultation Ground-Fault Circuit Interrupter This device protects you from dangerous shock The GFCI detects a difference in current between the black and white circuit wires (This could happen when electrical equipment is not working correctly, causing current “leakage” – known as a ground fault.) If a ground fault is detected, the GFCI can shut off electricity flow in as little as 1/40 of a second, protecting you from a dangerous shock

Safety & Health Consultation Grounding Hazards Some of the most frequently violated OSHA standards Metal parts of an electrical wiring system that we touch (switch plates, ceiling light fixtures, conduit, etc.) should be at zero volts relative to ground Housings of motors, appliances or tools that are plugged into improperly grounded circuits may become energized If you come into contact with an improperly grounded electrical device, YOU WILL BE SHOCKED

Safety & Health Consultation Overhead Powerline Hazards Most people don’t realize that overhead powerlines are usually not insulated Powerline workers need special training and personal protective equipment (PPE) to work safely Do not use metal ladders – instead, use fiberglass ladders Beware of powerlines when you work with ladders and scaffolding

Safety & Health Consultation Some Examples of OSHA Electrical Requirements....

Approval Approval. The conductors and equipment required or permitted by this subpart shall be acceptable only if approved Safety & Health Consultation (a)

Examination, Installation, and Use Employer Obligation –Electrical equipment must be free from recognized hazards that are likely to cause death or serious physical harm to employees: Cables exposed to sharp edges Splices Bare conductors Safety & Health Consultation (b)(1)

Safety & Health Consultation Examination. Safety of equipment shall determined using the following considerations: –Suitability of equipment for an identified purpose may be evidenced by listing or labeling for that identified purpose Examination, Installation, and Use (b)(2)

Mechanical Execution of Work Equipment shall be installed in a neat workmanlike manner Safety & Health Consultation (b)(7)

Unused openings shall be effectively closed to afford protection substantially equivalent to the wall of the equipment. Safety & Health Consultation Mechanical Execution of Work (b)(7)(i)

Safety & Health Consultation Electrical equipment may not be used unless the manufacturer's name, trademark, or other descriptive marking by which the organization responsible for the product may be identified is placed on the equipment Equipment Marking (e)(1) (e)(1)(i)

Safety & Health Consultation Other markings shall be provided giving voltage, current, wattage, or other ratings as necessary. The marking shall be of sufficient durability to withstand the environment involved Equipment Marking 480 V (e)(1)(ii)

Safety & Health Consultation Identification of Disconnecting Means and Circuits Each disconnecting means (dm) legibly marked to indicate its purpose –(Unless so arranged so the purpose is evident) A dm is a switch used to disconnect the conductors of a circuit from the source of current Disconnect switch for motor number (f)(1)

Identification of Disconnecting Means and Circuits Each service, feeder, and branch circuit, at its dm or overcurrent device, legibly and durably marked to indicate its purpose Switches and circuit breakers must be clearly labeled to indicate its circuit’s function Circuit breaker for motors 1,2,3, and (f)(2)

Safety & Health Consultation Example of properly labeled electric service: motors, disconnects and breakers

Disconnecting means shall be capable of being locked in the open position. Safety & Health Consultation Identification of Disconnecting Means and Circuits (f)(4)

Safety & Health Consultation Working Space about Electric Equipment Sufficient access and working space around all electrical equipment, provided & maintained to provide ready and safe operation and maintenance Not used for storage If located in aisle or general open area, working space shall be suitably guarded (g)

Safety & Health Consultation TABLE S-1 - WORKING CLEARANCES ____________________________________________ Nominal voltage Minimum clear distance to ground for condition (2)(ft.) __________________________________________ (a) (b) (c) ________________________________________ … (1)3 (1) … (1)3 3 1/2 4 ________________________________________ Footnote(1) Minimum clear distances may be 2 feet 6 inches for installations built prior to April 16, 1981.

Safety & Health Consultation Working Space about Electric Equipment If the nominal voltage to ground is from V: (g)(1)(i)

Safety & Health Consultation Equipment Illumination Illumination provided for all working spaces about service equipment, switchboards, panel- boards, and motor control centers installed indoors (g)(1)(v)

Safety & Health Consultation Headroom The minimum headroom of working spaces about service equipment, switchboards, panel- boards, or motor control centers shall be 6 feet 3 inches 6'3" (g)(1)(vi)

Guarding of Live Parts Live parts of electric equipment operating at 50 volts or more must be guarded. Safety & Health Consultation (g)(2)(i)

Safety & Health Consultation Identification of Conductors A conductor used as a grounded conductor shall be identifiable and distinguishable from all other conductors. A conductor used as an equipment grounding conductor shall be identifiable and distinguishable from all other conductors (a)(1)

Safety & Health Consultation Identification of Conductors Grounded conductor and equipment grounding conductors marked or color coated so that employees can i.d. and tell apart Grounded conductor is an energized circuit (conductor that is connected to earth through the system ground) Commonly referred to as the neutral

Safety & Health Consultation Grounding Conductors Equipment grounding conductor acts as a safeguard against insulation failure or faults in the other circuit conductors Not an energized conductor under normal conditions. Energized if a leak or fault in the normal current path Directs current back to the source Enabling fuses or circuit breakers to operate

Safety & Health Consultation Identification of Conductors Grounded conductor i.d. and distinguished from other conductors w/ white or gray Equipment grounding conductor i.d. and distinguished w/green, green w/ yellow stripes, or bare

Safety & Health Consultation Use and Identification of Grounded and Grounding Conductors No grounded conductor may be attached to any terminal or lead so as to reverse polarity Correct polarity between the ungrounded (hot) conductor, the grounded (neutral) conductor, and the grounding conductor must be maintained (a)(2)

Safety & Health Consultation

Safety factor of 20% Safety & Health Consultation Branch Circuits Circuit rating (amperes) Receptacle rating (amperes) Maximum load (amperes) 15 or TABLE S–4. — Maximum Cord- and Plug- Connected Load to Receptacle (b)(4)(ii)(B)

Safety & Health Consultation Disconnecting Means 1000kV General. Means provided to disconnect all conductors in a building from the service-entrance conductors. The disconnecting means shall plainly indicate whether it is in the open or closed position Installed at a readily accessible location (e)(1)

Safety & Health Consultation Services over 600 volts, nominal 1000kV Danger Guarded to make them accessible only to qualified persons Signs warning of high voltage shall be posted where other than qualified employees might come in contact with live parts (e)(2)

Safety & Health Consultation Overcurrent Protection 1000kV Danger 600 volts or less: –Overcurrent devices readily accessible to each employee –May not be located where they will be exposed to physical damage nor in the vicinity of easily ignitable material –Fuses and circuit breakers located or shielded that employees will not be burned or otherwise injured by their operation (f)

Safety & Health Consultation Circuit Breakers 1000kV Danger Circuit breakers shall clearly indicate whether they are in the open (off) or closed (on) position (f)(1)(vi)

Safety & Health Consultation Grounding The path to ground from circuits, equipment, and enclosures must be permanent and continuous Violation shown here is an extension cord with a missing grounding prong (g)(5)

Safety & Health Consultation Grounding Required to protect employees against: –Shock –Safeguard against fire –Protect equipment from damage

Safety & Health Consultation Grounding There are two kinds of grounding: –Electrical circuit or system grounding –Electrical equipment grounding

Safety & Health Consultation Electrical System Grounding One conductor of the circuit is intentionally grounded to earth Protects circuit from lightning, or other high voltage contact Stabilizes the voltage in the system so “expected voltage levels” are not exceeded under normal conditions

Safety & Health Consultation Equipment Grounding All metal frames & enclosures of equipment are grounded by a permanent connection or bond The equipment grounding conductor provides a path for dangerous fault current to return to the system ground at the supply source should a fault occur

Safety & Health Consultation Hand-Held Electric Tools Hand-held electric tools pose a potential danger because they make continuous good contact with the hand To protect you from shock, burns, and electrocution, tools must: –Have a three-wire cord with ground and be plugged into a grounded receptacle, or –Be double insulated, or –Be powered by a low-voltage isolation transformer (g)(6)(vi)(C)(3)

Safety & Health Consultation

Note: Properly bonded conduit and associated metal enclosures can also serve as a grounding conductor.

Safety & Health Consultation Guarding of Live Parts Must guard live parts of electric equipment operating at 50 volts or more against accidental contact by: –Approved cabinets/enclosures, or –Location or permanent partitions making them accessible only to qualified persons, or –Elevation of 8 ft. or more above the floor or working surface Mark entrances to guarded locations with conspicuous warning signs (g)(2)(i)

Safety & Health Consultation Other forms of approved enclosures, or by any of the following means by: –Location in a room, vault, accessible only to qualified persons –Permanent, substantial partitions or screens –By location on a suitable balcony or platform as to exclude unqualified persons –Elevation of 8 feet or more above the floor or other working surface Guarding of Live Parts (g)(2)

Safety & Health Consultation Guarding of Live Parts Must enclose or guard electric equipment in locations where it would be exposed to physical damage Violation shown here is physical damage to conduit (g)(2)(ii)

Safety & Health Consultation Wiring in Ducts No wiring systems of any type installed in ducts used to transport dust, loose stock or flammable vapors (a)(1)(ii)

Safety & Health Consultation Temporary Wiring All lamps for general illumination shall be protected from accidental contact or breakage by a suitable fixture or lampholder with a guard. Brass shell, paper-lined sockets, or other metal-cased sockets may not be used unless the shell is grounded (a)(2)(ix)

Safety & Health Consultation Temporary Wiring Flexible cords and cables shall be protected from accidental damage Sharp corners and projections shall be avoided. Where passing through doorways or other pinch points, flexible cords and cables shall be provided with protection to avoid damage (a)(2)(x)

Safety & Health Consultation Conductors can be damaged if they rub against the sharp edges of cabinets, boxes, or fittings Where they enter they must be protected by some type of clamp or rubber grommet The device used must close the hole through which the conductor passes as well as provide protection from abrasion Conductors Entering Boxes, Cabinets or Fittings (b)(1)

Safety & Health Consultation Conductors Entering Boxes, Cabinets or Fittings All pull boxes, junction boxes and fittings must be provided with covers identified for the purpose If covers are metal they must be grounded. Each outlet box must have a cover, faceplate or fixture canopy (b)(2)(i)

Safety & Health Consultation Use of Flexible Cords Where passing through doorways or other pinch points, flexible cords and cables shall be provided with protection to avoid damage (a)(2)(x)

Safety & Health Consultation Use of Flexible Cords More vulnerable than fixed wiring Do not use if one of the recognized wiring methods can be used instead Flexible cords can be damaged by: –Aging –Door or window edges –Staples or fastenings –Abrasion from adjacent materials –Activities in the area Improper use of flexible cords can cause shocks, burns or fire (g)

Safety & Health Consultation Permissible Uses of Flexible Cords Examples Pendant, or Fixture Wiring Portable lamps, tools or appliances Stationary equipment- to facilitate interchange (g)(1)(ii)

Safety & Health Consultation Prohibited Uses of Flexible Cords Examples Substitute for fixed wiring Run through walls, ceilings, floors, doors, or windows Concealed behind or attached to building surfaces (g)(1)

Flexible Cords Flexible cords must be connected to devices and fittings. –Strain relief must be provided to prevent pull from being directly transmitted to joints or terminal screws. Safety & Health Consultation (g)(2)(iii)

Safety & Health Consultation Electrical Safety Related Work Practices

Safety & Health Consultation 80% of electrically related accidents, incidents, and fatalities among Qualified Workers Caused by Arc Blast /Arc Flash

Safety & Health Consultation What electrical hazard is responsible for nearly 80% of the accidents, incidents, and fatalities among Unqualified Workers? Electrocution Usually associated with a lack of Equipment Grounding!

Safety & Health Consultation Electrical Safety Related Work Practices (a)(1) Premise Wiring. Installations of electric conductors and equipment within or on buildings or other structures, and on other premises such as yards, carnival parking, and other lots, and industrial substations; Equipment. A general term including material, fittings, devices, appliances, fixtures, apparatus, and the like, used as part of, or in connection with an electrical installation.

Safety & Health Consultation Does this standard apply to a technician working at a repair center, diagnosing / troubleshooting and repairing: Microwave ovens? Yes TV’s and VCR’s? Yes Computers? Yes Lamps? Yes Anything electrical? Yes

Safety & Health Consultation Protection by Electrical Installation Standards 1 – Avoid contact a – Guard b – Insulate c – Elevate 2 – Grounding (Equipment Ground) 3 - GFCI

Safety & Health Consultation Safety Related Work Practices Covers: Qualified persons (those who have training in avoiding the electrical hazards) Unqualified persons (those with little or no such training)

Safety & Health Consultation Safety Related Work Practices Qualified persons: (i.e. those permitted to work on or near exposed energized parts) shall, at a minimum, be trained in and familiar with the following: –The skills and techniques necessary to distinguish exposed live parts from other parts of electric equipment –The skills and techniques necessary to determine the nominal voltage of exposed live parts

Safety & Health Consultation Unqualified Persons.332(a) Training requirements apply to employees who face the risk of shock not reduced to a safe level by installation requirements of Subpart S (b)(2) also trained in electrical safe work practices not addressed here but which is necessary for their safety.334 Use of portable equipment

Safety & Health Consultation Unqualified Persons Another way to say this is, unqualified workers: Are normally protected by the installation requirements by Subpart S However If their work exposes them to electrical hazards which would otherwise be protected according to Subpart S, they must be trained. Trained to recognize and avoid hazards encountered or likely to encounter while working.

Safety & Health Consultation Safety Related Work Practices Unqualified person working near overhead lines, the person and the longest conductive object they may contact cannot come closer to any energized overhead line than the following distances: –For voltages to ground 50kV or below - 10 feet –For voltages to ground over 50kV - 10 feet plus 4 inches for every 10kV over 50kV

Safety & Health Consultation Safety Related Work Practices While any employee is exposed to contact with parts of fixed electric equipment or circuits which have been deenergized, the circuits energizing the parts shall be locked out or tagged or both*

Safety & Health Consultation Use of Portable Equipment (a) covers: –Cordsets (extension cords) –Cord and plug connected equipment –For unqualified as well as qualified workers

Safety & Health Consultation Use of Portable Equipment (a) –Don’t abuse, damage, or use for a rope (a)(1) In other words don’t use the cord to raise or lower equipment

Safety & Health Consultation This standard addresses the root cause factors of these recurring hazards…. As a result, we will have a positive and lasting effect on safety and ultimately eradicate recurring hazards.

Safety & Health Consultation Use of Portable Equipment –(a)(1) Don’t abuse damage, or use as a rope. –(a)(2) Visually inspect before use. –(a)(2) Loose parts, deformed/bent pins or blades, missing pins or blades, (GROUND PIN).

Safety & Health Consultation Use of Portable Equipment –(a)(2) Damage to outer jacket, evidence of damage, pinched /crushed. –(a)(2)(ii) Shall be removed from service and not used until repaired

Safety & Health Consultation Use of Portable Equipment The purpose of the equipment grounding conductor is to … Prevent Electrocution In the event of a fault or short circuit in the tool or equipment

Safety & Health Consultation Safety Related Work Practices Portable electric equipment and flexible cords used in highly conductive work locations, or in job locations where employees are likely to contact water or conductive liquids, shall be approved for those locations

Safety & Health Consultation Safety Related Work Practices Conductive articles of jewelry and clothing (such a watch bands, bracelets, rings, key chains, necklaces, etc...) may not be worn if they might contact exposed energized parts

Safety & Health Consultation Clues that Electrical Hazards Exist Tripped circuit breakers or blown fuses Warm tools, wires, cords, connections, or junction boxes GFCI that shuts off a circuit Worn or frayed insulation around wire or connection

Safety & Health Consultation Training Deenergizing electric equipment before inspecting or making repairs Using electric tools that are in good repair Using good judgment when working near energized lines Using appropriate protective equipment Train employees working with electric equipment in safe work practices, including:

Safety & Health Consultation Summary Hazards Inadequate wiring Exposed electrical parts Wires with bad insulation Ungrounded electrical systems and tools Overloaded circuits Damaged power tools and equipment Using the wrong PPE and tools Overhead powerlines All hazards are made worse in wet conditions Protective Measures Proper grounding Using GFCI’s Using fuses and circuit breakers Guarding live parts Proper use of flexible cords Training

Safety & Health Consultation Your Questions?