University of Nevada, Reno

ELECTRICAL SAFETY PROGRAM

Program Contact Person: John A. Braun, CSP Environmental Health and Safety University of Nevada, Reno Phone: 775-784-6478

ELECTRICAL SAFETY PROGRAM UNIVERSITY OF NEVADA, RENO TABLE OF CONTENTS 1.0 – INTRODUCTION 1.1 Policy 1.2 Purpose 1.3 Scope 2.0 – RESPONSIBILITY 2.1 Department Director 2.2 Supervisor 2.3 Employees 2.4 Department of Environmental Health and Safety (EH&S) 2.5 Contractors 3.0 – TRAINING 4.0 – EXAMINATION, INSTALLATION & USE OF EQUIPMENT 4.1 Free from Recognized Hazards 5.0 – IDENTIFICATION OF DISCONNECTING MEANS AND CIRCUITS 6.0 – GUARDING OF LIVE PARTS 7.0 – GENERAL WIRING DESIGN & PROTECTION 8.0 – REQUIREMENTS FOR TEMPORARY WIRING 9.0 – OPEN, CONDUCTORS, CLREARANCE FROM GROUND 9.1 Entrances and Access to Workspace 9.2 Working Space about Electric Equipment 9.3 Clear Spaces 10.0 – IDENTIFICATION OF CONDUCTORS 11.0 – POLLARITY OF CONNECTIONS 12.0 – GROUNDING 12.1 Grounding Paths 12.2 Grounding of Equipment connected by cords & Plugs 12.3 Ground-Fault Circuit-Interrupters 12.4 Permanently Mounted Type 12.5 Classes of GFCIs 12.6 Testing Ground-Fault Circuit-Interrupters 13.0 – CABINETS, BOXES, & FITTINGS 14.0 – FLEXIBLE CORDS AND CABLES 14.1 Identification, Splices & Terminations 15.0 – EXTENSION CORDS 15.1 Relocatable Power Tap (RRT) or Power Strips 15.2 Surge Protective Device (SPD) Power Strips 16.0 – SELECTION & USE OF WORK PRACTICES 16.1 Working on Electrical Systems 16.2 Overhead Power Lines 16.3 Illumination 16.4 Confined or Enclosed Work Spaces 2

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16.5 Conductive Materials & Equipment 16.6 Portable Ladders 16.7 Conductive Apparel 16.8 Housekeeping 17.0 – VEHICLES & MECHANICAL EQUIPMENT 18.0 – INTERLOCKS 19.0 – PORTABLE ELECTRICAL EQUIPMENT & EXTENSION CORDS 20.0 – ELECTRICAL POWER & LIGHTING CIRCUITS 20.1 Routine Opening & Closing of Circuits 20.2 Re-closing Circuits after a Protective Device Operates 21.0 – TEST EQUIPMENT & INSTRUMENTS 22.0 – FLAMMABLE OR IGNITABLE MATERIALS 23.0 – SAFEGUARDS FOR PERSONNEL PROTECTION 23.1 Protective Equipment 23.2 Workmanship & finish 24.0 – IN-SERVICE CARE & USE 25.0 – GENERAL PROTECTIVE EQUIPMENT & TOOLS 26.0 – GLOSSARY

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ELECTRICAL SAFETY PROGRAM

1.0 INTRODUCTION 1.1 Policy It is the policy of the University of Nevada, Reno (UNR) to ensure safe and healthy learning, research, work, entertainment and student living environments for faculty, staff, students and visitors. Implicit in this policy is a requirement to provide all individuals with pertinent information about potential electrical hazards. 1.2 Purpose The purpose of this Electrical Safety Program is to communicate information about hazards of electricity that employees use or may come in contact with as part of their work. UNR’s Electrical Safety Program stresses that electricity has long been recognized as a serious workplace hazard, exposing users to such dangers as electric shock, electrocution, fires and explosions. The objective of the Electrical Safety Program is to minimize such potential hazards by specifying proper use and design characteristics of electrical devices, equipment and systems. UNR’s Electrical Safety Program is based on OSHA's electrical standards that were developed to cover only those parts of any electrical system that a user would normally use or come in contact. Exposed and/or operating elements of an electrical installation - lighting equipment, motors, machines, appliances, switches, controls, enclosures, etc. - must be so constructed, installed and maintained as to minimize electrical dangers to people in any workplace or occupancy. 1.3 Scope This program provides guidelines to all University of Nevada, Reno properties, to all work performed on the University of Nevada, Reno campus, and to all work performed by University of Nevada, Reno employees regardless of jobsite location. All employees who face a risk of electrical shock, burns or related injuries must be trained in electrical safety work practices. In addition, employees that work around, but not on, electrical systems must be trained in the inherent danger of electricity. This Electrical Safety Program describes work practices for both qualified and unqualified persons.

Qualified persons are those who have received specific training and have demonstrated the skills necessary to work safely on or near exposed energized parts. A person may be qualified to work, for example, on circuits up to 600 volts, but may be unqualified to work on higher voltages. Only qualified persons may place or remove locks and tags on energized electrical systems. Unqualified persons are those with little or no electrical safety training or have not been qualified by the University of Nevada, Reno.

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An employee undergoing on-the-job training who has demonstrated the ability to perform duties safely at his or her level of training, and who is under the direct supervision of a qualified person, is considered to be a qualified person for the purpose of those duties. Work practices covered by this program include persons working on or near: •

Premises wiring: Installations of electric conductors and equipment in or on buildings or other structures, and in other areas such as yards, parking and other lots, and industrial substations.

•

Wiring for connection to supply: Installations of conductors that connect to the supply of electricity.

•

Other wiring: Installation of other outside conductors on the premises.

•

Optical fiber cable: Installation of optical fiber cable near or with electric wiring.

Work practices covered by this program also includes work performed by unqualified persons near or with electric power generation, transmission, and distribution installations, communications installations, installations in vehicles, and railway equipment. This program does not apply to: •

Work performed by qualified persons on or directly associated with electric power generation, transmission, and distribution, including the repair of overhead or underground distribution lines, line clearance tree trimming and utility pole replacement.

•

Work in a generating plant where the electric circuits are commingled with power generation equipment or circuits and where there is exposure to high voltage or lack of overcurrent protection.

•

Communication installations.

In addition, the following apply universally on UNR facilities: 1. Multi-outlet conversions (example: a plug-in outlet cover converting two outlets into six) will not be attached to standard duplex electrical outlets. 2. Flexible cords (extension cords) will not be plugged into another extension cord. (i.e., an unfused outlet strip plugged into a 12 foot long extension cord, or a cheap, two-conductor extension cord plugged into another.) 3. All extension cords or outlet strips must be grounded (ground pin plugs.) 4. Grounded conductors must be continuous from device or appliance to the electrical circuit (refrigerators, heaters, fans, etc.). Ground pins must not be removed. 5. Appliance cords or extension cords must not be used if insulation is damaged, spliced, or bare conductor wires are visible. 6. Appliance cords or extension cords must not be run through doorways, windows, uncovered across floors or through walls. Appliance cords or extension cords may not be permanently attached to the building’s structure or fixtures. (no nails, staples, tape, twist ties, knots, etc.) 7. Electrical circuits must be identified and marked on the chart found inside the breaker box panel door. Missing charts must be replaced. 5

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The OSHA electrical standards are based on the National Fire Protection Association's standard NFPA 70E, Electrical Safety Requirements for Employee Workplaces, and the NFPA 70 Committee derived Part I of their document from the 1978 edition of the National Electrical Code (NEC). The standards extracted from the NEC were those considered to most directly apply to employee safety and least likely to change with each new edition of the NEC. OSHA's electrical standards are performance oriented; therefore they contain few direct references to the NEC. However, the NEC contains specific information as to how the required performance can be obtained.

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2.0 RESPONSIBILITIES 2.1 Department Director The department director is responsible for ensuring that all personnel are properly trained. The director is responsible for ensuring their employees have the correct tools, including personal protective equipment, to properly and safely complete their assigned jobs. 2.2 Supervisor Supervisors are responsible for: ¾ Ensuring that all electrical outlets, circuit breaker panels are properly labeled ¾ Ensuring electrical safety training is available to employees ¾ Ensuring employees are trained on electrical safety ¾ Ensuring that training is given in accordance with this program ¾ Ensuring adequate documentation and tracking of all training within their group ¾ Ensuring that work with electricity is performed in accordance with accepted safe practices of the job ¾ Ensuring that employees follow established safety procedures ¾ Adequately informing any non-University personnel sharing the same work area of the electrical hazards to which their employees may be exposed while performing their work ¾ Ensuring compliance with the University Lockout/Tagout Program ¾ Maintaining a copy of this written program in the workplace 2.3 Employees Employees are responsible for: ¾ Knowing the hazards and precautionary procedures for electrical hazards in their work area ¾ Ensuring that the electrical outlets and other electrical equipment are used properly. ¾ Attending required training ¾ Planning and conducting operations in accordance with established procedures and good safety practices ¾ Complying with the University Lockout/Tagout Program ¾ Using personal protective equipment and clothing in accordance with prescribed training

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2.4 Department of Environmental Health and Safety (EH&S) The EH&S Department is responsible for providing resources (i.e. reference materials) and technical support to ensure employees are protected from electrical hazards. Specific responsibilities include: ¾ Developing and evaluating the University’s Written Electrical Safety Program. ¾ Assisting supervisors in identifying electrical hazards presented in the work area. ¾ Providing electrical safety training to supervisors. ¾ Assisting supervisors with employee training. ¾ Recommending appropriate engineering controls, administrative controls and personal protective equipment. 2.5 Contractors Contractors must comply with all local, state, and federal safety requirements, and assure that all of their employees performing work on University of Nevada, Reno property have been suitably trained. Contractors’ safety programs must meet or exceed the University of Nevada, Reno’s Electrical Safety Program.

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3.0 Training Employees who face a risk of electrical shock that is not reduced to a safe level by the electrical installation (e.g., systems that meet the National Electrical Code and OSHA requirements) must be trained per the requirements of this program. Employees in the following occupations must be trained: ¾ Employee who faces a risk of injury due to electric shock or electrical hazards

¾ Material handling equipment operators

¾ Supervisors of employees performing work around or on electrical systems

¾ Painters

¾ Mechanics and repairers ¾ Riggers and roustabouts

¾ Electrical and electronic engineers

¾ Stationary engineers

¾ Electrical and electronic equipment assemblers

¾ Welders

¾ Electrical and electronic technicians EXCEPTION: Employees in these groups do not require training if their work does not bring them close enough to exposed parts of electric circuits—operating at 50 volts or more to ground—for a hazard to exist. Qualified persons who work on or near energized equipment involving either direct contact, or contact by means of tools or materials, must be trained in the following: ¾ Proper precautionary work practices, personal protective equipment, insulating and shielding materials, and the use of insulated tools ¾ The skills and techniques necessary to distinguish exposed live parts from other parts of electric equipment ¾ The skills and techniques necessary to determine the nominal voltage of exposed live parts ¾ The clearance distances specified for working on or near exposed energized parts and the corresponding voltages to which the qualified person will be exposed Training must be performed before the employee is assigned duties involving work around or on electrical systems. Retraining will be performed whenever inspections performed by EH&S or the employee’s supervisor indicates that an employee does not have the necessary knowledge or skills to safely work on or around electrical systems. Retraining will also be performed when policies or procedures change and/or new equipment or systems are introduced into the work area. Training will involve both classroom and on-the-job training. Training will be coordinated between the work supervisors and customized to reflect the scope of work performed within that work unit. The work supervisor will review, or coordinate review, of the work performed by each employee to assure that they demonstrate the skills and techniques needed to perform their work safely. 9

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4.0 EXAMINATION, INSTALLATION & USE OF EQUIPMENT Electrical equipment shall be free from recognized hazards that are likely to cause death or serious physical harm to employees. Safety of equipment shall be determined using the following considerations: ¾ Suitability for installation and use in conformity with the provisions of this subpart. Suitability of equipment for an identified purpose may be evidenced by listing or labeling for that identified purpose. ¾ Mechanical strength and durability, including, for parts designed to enclose and protect other equipment, the adequacy of the protection thus provided. ¾ Electrical insulation. ¾ Heating effects under conditions of use. ¾ Arcing effects. ¾ Classification by type, size, voltage, current capacity, and specific use. ¾ Other factors which contribute to the practical safeguarding of employees using or likely to come in contact with the equipment. Note that this requirement is, in effect, and electrical "general duty clause" similar to Section 5(a)(1) of the OSH Act: "each employer shall furnish . . . a place of employment which is free from recognized hazards that are causing or are likely to cause death or serious harm to his employees." 4.1 Free from Recognized Hazards Electrical equipment must be free from recognized hazards that are likely to cause death or serious physical harm. Equipment must be suitable for the installation and use, and must be installed and maintained in accordance with the manufacturer’s instructions, the National Electrical Code (NEC) and OSHA. “Suitable” means that the equipment is listed or labeled for the intended use by a nationally recognized testing laboratory such as Factory Mutual (FM) or Underwriters Laboratory (UL).

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5.0 IDENTIFICATION OF DISCONNECTING MEANS AND CIRCUITS A disconnecting means is a switch that is used to disconnect the conductors of a circuit from the source of electric current. Disconnect switches enable a circuit to be opened, stopping the flow of electricity, and thus can effectively protect workers and equipment. Each disconnect switch or overcurrent device required for a service, feeder, or branch circuit must be clearly labeled to indicate the circuit's function, and the label or marking should be located at the point where the circuit originates. For example, on a panel that controls several motors or on a motor control center, each disconnect must be clearly marked to indicate the motor to which each circuit is connected. In the figure below, the Number 2 circuit breaker in the panel box supplies current only to disconnect Number 2, this in turn controls the current to motor Number 2. This current to motor Number 2 can be shut off by the Number 2 circuit breaker or the Number 2 disconnect. If the purpose of the circuit is obvious, no identification of the disconnected circuit is required. All labels and markings must be durable enough to withstand weather, chemicals, heat, corrosion, or any other environment to which they may be exposed.

Each Disconnect and Circuit Requires Identification

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6.0 GUARDING OF LIVE PARTS Except as required or permitted elsewhere in this subpart; live parts of electric equipment operating at 50 volts or more shall be guarded against accidental contact by approved cabinets or other forms of approved enclosures, or by any of the following means: ¾ By location in a room, vault, or similar enclosure that is accessible only to qualified persons. ¾ By suitable permanent, substantial partitions or screens so arranged that only qualified persons will have access to the space within reach of the live parts. Any openings in such partitions or screens shall be so sized and located that persons are not likely to come into accidental contact with the live parts or to bring conducting objects into contact with them. It is good practice to use covers, screens or partitions which can only be removed by use of tools, so that unqualified persons are less likely to violate them. ¾ By location on a suitable balcony, gallery, or platform. ¾ By elevation of 8 feet or more above the floor or other working surface. Note that, although equipment elevated at least 8 feet is considered to be guarded, this may not be adequate if material being handled is likely to make contact with live parts. Enclosures or guards shall be so arranged and of such strength as to prevent damage in locations where electric equipment would be exposed to physical damage. Entrances to rooms and other guarded locations containing exposed live parts shall be marked with conspicuous warning signs forbidding unqualified persons to enter.

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7.0 General Wiring Design and Protection New electrical wiring, and the modification, extension or replacement of existing wiring must conform to the requirements of the NEC, the Virginia Uniform Statewide Building Code, OSHA and the following: ¾ No grounded conductor may be attached to any terminal or lead so as to reverse designated polarity. ¾ The grounding terminal or grounding-type device on receptacles, cord connector, or attachment plug may not be used for any purpose other than grounding. ¾ Conductors and equipment must be protected from over-current above their safe current carrying capacity. ¾ All AC systems of 50 to 1,000 volts must normally be grounded as required by the NEC and OSHA. The path to ground from circuits, equipment and enclosures must be permanent and continuous. Existing ungrounded premises wiring do not meet the OSHA requirements and must be replaced or modified as needed to meet this requirement. For information on exceptions to these requirements, please contact EH&S. ¾ Conductors entering boxes, cabinets or fittings must be protected from abrasion, and openings through which conductors enter must be effectively closed. Unused openings in cabinets, boxes and fixtures must also be effectively closed. ¾ All pull boxes, junction boxes and fittings must be provided with covers approved for the purpose. If metal covers are used they must be grounded. In completed installations, each outlet box must have a cover, faceplate or fixture canopy. Pull boxes and junction boxes for systems over 600 volts, nominal, must provide complete enclosure , the boxes must be closed by suitable covers securely fastened in place, and the cover must be permanently marked “High Voltage”. ¾ Switchboards and panelboards that have exposed live parts must be located in permanently dry locations and accessible to qualified persons only. Panelboards must be mounted in cabinets, cutout boxes or other approved enclosure, and must be dead front unless accessible to qualified persons only. Exposed blades of knife switches must be dead when open. Receptacles installed in damp or wet locations must be suitable for the location. ¾ Cabinets, cutout boxes, fittings, boxes and panelboard enclosures in damp or wet locations must be installed so as to prevent moisture or water from entering and accumulating within the enclosure. In wet locations the enclosures must be weatherproof. ¾ Fixtures, lamp holders, lamps, rosettes, and receptacles may have no live parts normally exposed to employee contact. ¾ Screw-base light socket adapters do not maintain ground continuity and may not be used. ¾ Multi-plug receptacle adapters may not maintain ground continuity or may overload circuits and must not be used. If additional receptacles are needed in a work location, additional circuits and/or receptacles must be installed. Multi-plug power strips with

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over-current protection are acceptable for use with electronic equipment if they are used to reduce line noise or to provide surge or over-current protection. ¾ Electrical equipment, wiring methods and installations of equipment in hazardous classified locations must be intrinsically safe, approved for the location, or safe for the location. Hazardous classified locations are areas where flammable liquids, gases, vapors, or combustible dusts or fibers exist or could exist in sufficient quantities to produce an explosion or fire.

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8.0 Requirements for Temporary Wiring Temporary electrical power and lighting installations that are 600 volts or less, including flexible cords, cables and extension cords, may only be used during and for renovation, maintenance, repair, or experimental work. Temporary wiring may also be used for decorative lighting for special events and similar purposes for a period not to exceed 90 days. The following additional requirements apply: ¾ Ground-fault protection (e.g., ground-fault circuit interrupters or GFCI) must be provided on all temporary-wiring circuits, including extension cords, used on construction sites. ¾ In general, all equipment and tools connected by cord and plug must be grounded. Listed or labeled double insulated tools and appliances need not be grounded. For information on exceptions to these requirements, please contact EH&S. ¾ Feeders must originate in an approved distribution center, such as a panelboard, that is rated for the voltages and currents the system is expected to carry. ¾ Branch circuits must originate in an approved power outlet or panelboard. ¾ Neither bare conductors nor earth returns may be used for the wiring of any temporary circuit. ¾ Receptacles must be of the grounding type. Unless installed in a complete metallic raceway, each branch circuit must contain a separate equipment-grounding conductor, and all receptacles must be electrically connected to the grounding conductor. ¾ Flexible cords and cables must be of an approved type and suitable for the location and intended use. They may only be used for pendants, wiring of fixtures, connection of portable lamps or appliances, elevators, hoists, connection of stationary equipment where frequently interchanged, prevention of transmission of noise or vibration, data processing cables, or where needed to permit maintenance or repair. They may not be used as a substitute for fixed wiring, where run through holes in walls, ceilings or floors, where run through doorways, windows or similar openings, where attached to building surfaces, or where concealed behind building walls, ceilings or floors. ¾ Suitable disconnecting switches or plug connects must be installed to permit the disconnection of all ungrounded conductors of each temporary circuit. ¾ Lamps for general illumination must be protected from accidental contact or damage, either by elevating the fixture or by providing a suitable guard. Handlamps supplied by a flexible cord must be equipped with a handle of molded composition or other approved material and must be equipped with a substantial bulb guard. ¾ Flexible cords and cables must be protected from accidental damage. Sharp corners and projections are to be avoided. Flexible cords and cables must be protected from damage when they pass through doorways or other pinch points.

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9.0 OPEN, CONDUCTORS, CLREARANCE FROM GROUND Open conductors must be located at least 10 feet above any finished grade, sidewalk or projection, 12 feet above areas subject to non-truck traffic, 15 feet above areas subject to truck traffic, and 18 feet above public streets, roads or driveways. 9.1 Entrances and Access to Workspace In any workspace where there is electric equipment operating at over 600 volts, there must be at least one entrance at least 24 inches wide and 6 feet, 6 inches high to permit escape in the event of an emergency. Any exposed energized conductors operating at any voltage and located near the entrance must be guarded to prevent accidental contact. Any insulated energized conductors operating at over 600 volts and located next to the entrance must also be guarded. 9.2 Working Space about Electric Equipment Sufficient access and working space must be provided and maintained around all electric equipment to permit ready and safe operation and maintenance of the equipment. Working clearances may not be less than 30 inches in front of electric equipment. Except as permitted by OSHA or the NEC, the working space in front of live parts operating at 600 volts or less that requires servicing, inspection or maintenance while energized may not be less than indicated in Table 1. This working space may not be used for storage. 9.3 Clear Spaces Working space required by this subpart may not be used for storage. When normally enclosed live parts are exposed for inspection or servicing, the working space, if in a passageway or general open space, shall be suitably guarded. TABLE 1 Working Clearances Nominal Voltage to Minimum Clear Distance for Condition (3) Ground A B (1) 0-150 3’ 3’ (1) 151-600 3’ (1) 3-1/2’ 601-2,500 3’ 4’

C 3’ 4’ 5’

2,501-9,000

4’

5’

6’

9,001-25,000

5’

6’

9’

25,001-75 kV (2)

6’

8’

10’

Above 75 kV (2)

8’

10’

12’

(1) Minimum clear distance may be 2-1/2’ for installations built prior to April 16, 1981. (2) Minimum clear distance in front of electrical equipment with nominal voltage to ground above 25 kV may be the same as for 25 kV under conditions A, B and C for installations built prior to April 16, 1981.

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(3) Conditions A, B and C are as follows: (A) Exposed live parts on one side and no live or grounded parts on the other side of the working space, or exposed live parts on both sides are effectively guarded by an insulating material. Insulated wire or insulated bus bars operating at not over 300 volts are not considered live parts. Concrete, brick or tile walls are considered to be grounded. (B) Exposed live parts on one side and grounded parts on the other. (C) Exposed live parts on both sides of the workspace not guarded as per condition (A), with the operator between.

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10.0 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. The grounded conductor is an energized circuit conductor that is connected to earth through the system ground. It is commonly referred to as the neutral. The equipment grounding conductor is not an energized conductor under normal conditions. The equipment grounding conductor acts as a safeguard against insulation failure or faults in the other circuit conductors. The equipment grounding conductor is energized only if there is a leak or fault in the normal current path, and it directs this current back to the source. Directing the fault current back to the source enables protective devices, such as circuit breakers or fuses, to operate thus preventing fires and reducing the hazard of electrical shocks. The grounded and equipment grounding conductors of an electrical circuit must be marked or color coded in a way that allows employees to identify them and tell them apart from each other and from the other conductors in the circuit. The figure below illustrates a distribution panelboard. One means by which each conductor's use is identified and made distinguishable from the other circuit conductors is the use of color coding. Acceptable color coding includes the method required by the National Electrical Code, Section 210-5. The Code states: "The grounded conductor of a branch circuit shall be identified by a continuous white or natural gray color." Also, "The equipment grounding conductor of a branch circuit shall be identified by a continuous green color or a continuous green color with one or more yellow stripes unless it is bare." Bare copper or aluminum wire is permitted for use as a grounding conductor.

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11.0 POLARITY OF CONNECTIONS No grounded conductor may be attached to any terminal or lead so as to reverse designated polarity. A grounding terminal or grounding-type device on a receptacle, cord connector, or attachment plug may not be used for purposes other than grounding. NOTE: Some equipment will operate properly even though the supply wires are not connected in the order designated by design or the manufacturer. Improper connection of these conductors is most prevalent on the smaller branch circuit typically associated with standard 120 volt receptacle outlets, lighting fixtures and cord- and plug-connected equipment. When plugs, receptacles, and connectors are used in an electrical branch circuit, correct polarity between the ungrounded (hot) conductor, the grounded (neutral) conductor, and the grounding conductor must be maintained. Reversed polarity is a condition when the identified circuit conductor (the grounded conductor or neutral) is incorrectly connected to the ungrounded or "hot" terminal of a plug, receptacle, or other type of connector. The figure below shows the correct wiring for the common 120-volt outlet with a portable hand tool attached.

Suppose that the black (ungrounded) and white (grounded) conductors are reversed as shown in the figure below. This is the traditional reversed polarity. Although a shock hazard may not exist, there are other mechanical hazards that can occur.

For example, if an internal fault should occur in the wiring as shown in the figure below, the 19

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equipment would not stop when the switch is released or would start as soon as a person plugs the supply cord into the improperly wired outlet. This could result in serious injury.

The figure below shows the white (grounded) and green (grounding) conductors reversed. Although it is not fitting, considering OSHA or code terminology, to call this reversed polarity, a hazard can still exist. In this case, due to the wiring error, the white wire is being used to provide equipment grounding. Under certain conditions, this could be dangerous.

The figure below shows an extremely dangerous situation. In this example, the black (ungrounded) and green (grounding) conductors have been reversed. The metal case of the equipment is at 120 volts with reference to the surroundings. As soon as a person picks up the equipment and touches a conductive surface in their surrounding, they will receive a serious, or even deadly, shock. Although the equipment will not work with this wiring error, it would not be unusual for a person to pick up the equipment before realizing this. The person may even attempt to troubleshoot the problem before unplugging the power cord.

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Correct polarity is achieved when the grounded conductor is connected to the corresponding grounded terminal and the ungrounded conductor is connected to the corresponding ungrounded terminal. The reverse of the designated polarity is prohibited. The figure below illustrates a duplex receptacle correctly wired. Terminals are designated and identified to avoid confusion. An easy way to remember the correct polarity is "white to light" - the white (grounded) wire should be connected to the light or nickel-colored terminal; "black to brass" - the black or multicolored (ungrounded) wire should be connected to the brass terminal; and "green to green" - the green or bare (grounding) wire should be connected to the green hexagonal head terminal screw.

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12.0 GROUNDING This section contains grounding requirements for systems, circuits, and equipment. Grounding electrical circuits and electrical equipment is required to protect employees against electrical shock, safeguard against fire, and protect against damage to electrical equipment. There are two kinds of grounding: (1) electrical circuit or system grounding, and (2) electrical equipment grounding. Electrical system grounding is accomplished when one conductor of the circuit is intentionally connected to earth. This is done to protect the circuit should lightning strike or other high voltage contact occur. Grounding a system also stabilizes the voltage in the system so "expected voltage levels" are not exceeded under normal conditions. The second kind of ground is equipment grounding. This is accomplished when all metal frames of equipment and enclosures containing electrical equipment or conductors are grounded by means of a permanent and continuous connection or bond. The equipment grounding conductor provides a path for dangerous fault current to return to the system ground at the supply source of the circuit should an insulation failure take place. If installed properly, the equipment grounding conductor is the current path that enables protective devices, such as circuit breakers and fuses, to operate when a fault occurs. The figure below illustrates both types of grounding.

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12.1 Grounding Path The path to ground from circuits, equipment, and enclosures shall be permanent and continuous. This requirement was extracted from NEC 250-51, Effective Grounding Path, which is more complete and fundamental to the understanding of electrical safety. It states that the path to ground: 1. "Shall be permanent and continuous." (If the path is installed in such a way that damage, corrosion, loosening, etc. may impair the continuity during the life of the installation, then shock and burn hazards will develop.) 2. "Shall have capacity to conduct safely any fault current likely to be imposed on it." (Fault currents may be many times normal currents, and such high currents may melt or burn metal at points of poor conductivity. These high temperatures may be a hazard in themselves, and they may destroy the continuity of the ground-fault path.) 3. "Shall have sufficiently low impedance to limit the voltage to ground and to facilitate the operation of the circuit protective devices in the circuit." (If the ground-fault path has a high impedance, there will be hazardous voltages whenever fault currents attempt to flow. Also, if the impedance is high, the fault current will be limited to some value so low that the fuse or circuit breaker will not operate promptly, if at all.) It is important to remember the following regarding safe grounding paths: ¾ The fault current in A-C circuits will be limited by the sum of resistance and reactance, and the only low-reactance path is that which closely follows the circuit conductors. ¾ If a metallic raceway system is used, make sure that the metallic system is continuous and permanent. ¾ In cases where a metallic raceway system is not used, provide a green or bare equipmentgrounding conductor close to the supply conductors to assure that all enclosures are bonded together and to the source. 12.2 Grounding of Equipment Connected By Cord & Plug Under any of the conditions described below, exposed non-current-carrying metal parts of cord-and plug-connected equipment which may become energized shall be grounded. a. If in a hazardous (classified) location. b. If operated at over 150 volts to ground, except for guarded motors and metal frames of electrically heated appliances if the appliance frames are permanently and effectively insulated from ground. c. If the equipment is of the following types: 1. Refrigerators, freezers, and air conditioners; 2. Clothes-washing, clothes-drying and dishwashing machines, sump pumps, and electrical aquarium equipment; 3. Hand-held motor-operated tools; 4. Motor-operated appliances of the following types: hedge clippers, lawn mowers, snow blowers, and wet scrubbers; 5. Cord- and plug-connected appliances used in damp or wet locations or by employees 23

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standing on the ground or on metal floors or working inside of metal tanks or boilers; 6. Portable and mobile X-ray and associated equipment; 7. Tools likely to be used in wet and conductive locations; and 8. Portable hand lamps. Under the conditions described above, exposed non-current-carrying metal parts of cord- and plug-connected equipment must be grounded. Grounding metal parts is not required where the equipment is supplied through an isolating transformer with an ungrounded secondary of not over 50 volts or if portable tools are protected by an approved system of double insulation. To ground cord- and plug-connected equipment, a third wire is commonly provided in the cord set and a third prong in the plug. The third wire serves as an equipment grounding conductor which is connected to the metal housing of a portable tool and a metal grounding bus inside the service entrance equipment. The service entrance equipment is located at the entrance point of the electric supply for a building or plant and contains, or serves other panelboards which contain, branch circuit protective devices such as fuses and circuit breakers. The third wire provides a path for fault current should an insulation failure occur. In this manner, dangerous fault current will be directed back to the source, the service entrance, and will enable circuit breakers or fuses to operate, thus opening the circuit and stopping the current flow. The figure below illustrates the potential shock hazard that exists when no third wire, grounding conductor, is used. If a fault occurs, most of the current will follow the path of least resistance. If the worker provides a path to ground as shown, some portion of the current will flow away from the grounded white conductor (neutral) and return to ground through the worker. The severity of the shock received will depend on the amount of current that flows through the worker.

The figure below illustrates the advantage of a properly connected grounded conductor. It should be noted that properly bonded conduit and associated metal enclosures can also serve as a grounding conductor.

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Tools likely to be used in wet and conductive locations need not be grounded if supplied through an isolating transformer with an ungrounded secondary of not over 50 volts. Listed or labeled portable tools and appliances protected by an approved system of double insulation, or its equivalent, need not be grounded. If such a system is employed, the equipment shall be distinctively marked to indicate that the tool or appliance utilizes an approved system of double insulation. 12.3 Ground-Fault Circuit-Interrupters In most cases, insulation and grounding are used to prevent injury from electrical wiring systems or equipment. However, there are instances when these recognized methods do not provide the degree of protection required. To help appreciate this, let's consider a few examples of where ground fault circuit interrupters would provide additional protection. Many portable hand tools, such as electric drills, are now manufactured with non-metallic cases. If approved, we refer to such tools as double insulated. Although this design method assists in reducing the risk from grounding deficiencies, a shock hazard can still exist. In many cases, persons must use such electrical equipment where there is considerable moisture or wetness. Although the person is insulated from the electrical wiring and components, there is still the possibility that water can enter the tool housing. Ordinary water is a conductor of electricity. Therefore, if the water contacts energized parts; a path will be provided from inside the housing to the outside, bypassing the double insulation. When a person holding a hand tool under these 25

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conditions touches another conductive surface in their work environment, an electric shock will result. Double-insulated equipment or equipment with non-metallic housings, that does not require grounding under the National Electrical Code, is frequently used around sinks or in situations where the equipment could be dropped into water. Frequently, the initial human response is to grab for the equipment. If a person's hand is placed in the water and another portion of their body is in contact with a conductive surface, a serious or deadly electric shock can occur. In construction work and regular factory maintenance work, it is frequently necessary to use extension cord sets with portable equipment. These cords are regularly exposed to physical damage. Although safe work procedures require adequate protection, it is not possible to prevent all damage. Frequently, the damage is only to the insulation, exposing energized conductors. It is not unusual for a person to handle the cord often with the possibility of contacting the exposed wires while holding a metal case tool or while in contact with other conductive surfaces. The amount of current which flows under such conditions will be enough to cause serious human response. This can result in falls, physical injury and in many cases death. Since neither the insulation (double insulation) nor grounding can provide protection under these conditions, it is necessary to use other protective measures. One acceptable method is a ground fault circuit interrupter, commonly referred to as a GFCI. How Ground-Fault Circuit-Interrupters Work A ground-fault circuit-interrupter is not an overcurrent device like a fuse or circuit breaker. GFCI's are designed to sense an imbalance in current flow over the normal path. The GFCI contains a special sensor that monitors the strength of the magnetic field around each wire in the circuit when current is flowing. The magnetic field around a wire is directly proportional to the amount of current flow, thus the circuitry can accurately translate the magnetic information into current flow. If the current flowing in the black (ungrounded) wire is within 5 (plus or minus 1) mill amperes (mA) of the current flowing in the white (grounded) wire at any given instant, the circuitry considers the situation normal. All the current is flowing in the normal path. If, however, the current flow in the two wires differs by more than 5 mA, the GFCI will quickly open the circuit. This is illustrated in the figure below.

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Note that the GFCI will open the circuit if 5 mA or more of current returns to the service entrance by any path other than the intended white (grounded) conductor. If the equipment grounding conductor is properly installed and maintained, this will happen as soon as the faulty tool is plugged in. If by chance this grounding conductor is not intact and of low-impedance, the GFCI may not trip out until a person provides a path. In this case, the person will receive a shock, but the GFCI should trip out so quickly that the shock will not be harmful. Types of Ground-Fault Circuit-Interrupters There are several types of GFCI's available, with some variations to each type. Although all types will provide ground-fault protection, the specific application may dictate one type over another. ¾ Circuit-Breaker Type The circuit-breaker type includes the functions of a standard circuit breaker with the additional functions of a GFCI. It is installed in a panelboard and can protect an entire branch circuit with multiple outlets. It is a direct replacement for a standard circuit breaker of the same rating. ¾ Receptacle Type The receptacle style GFCI incorporates within one device one or more receptacle outlets, protected by the GFCI. Such devices are becoming very popular because of their low cost. Most are of the duplex receptacle configuration and can provide GFCI protection for additional non-GFCI type receptacles connected "down stream" from the GFCI unit. 12.4 Permanently Mounted Type ¾ The permanently mounted types are mounted in an enclosure and designed to be permanently wired to the supply. Frequently they are used around large commercial swimming pools or similar wet locations. ¾ Portable Type – there are several styles of portable GFCI's are available. The portable types are designed to be easily transported from one location to another. They usually 27

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contain one or more integral receptacle outlets protected by the GFCI module. Some models are designed to plug into existing non-GFCI protected outlets, or in some cases, are connected with a cord and plug arrangement. The portable types also incorporate a no-voltage release device which will disconnect power to the outlets if any supply conductor is open. Units approved for use outdoors will be in enclosures suitable for the environment. If exposed to rain, they must be listed as rainproof. ¾ Cord Connected Type The power supply cord type GFCI consists of an attachment plug which incorporates the GFCI module. It provides protection for the cord and any equipment attached to the cord. The attachment plug has a non-standard appearance and is equipped with test and reset buttons. Like the portable type, it incorporates a novoltage release device which will disconnect power to the load if any supply conductor is open. 12.5 Classes of Ground-Fault Circuit-Interrupters Ground-Fault Circuit-Interrupters are divided into two classes: Class A and Class B. The Class A device is designed to trip when current flow, in other than the normal path, is 6 milliamperes or greater. The specification is 5 milliamperes ± 1 milliampere. The Class B device will trip when current flow, in other than the normal path, is 20 milliamperes or greater. Class B devices are approved for use on underwater swimming pool lighting installed prior to the adoption of the 1965 National Electrical Code. 12.6 Testing Ground-Fault Circuit-Interrupters Due to the complexity of a GFCI, it is necessary to test the device on a regular basis. For permanently wired devices, a monthly test is recommended. Portable type GFCI's should be tested each time before use. GFCI's have a built-in test circuit which imposes an artificial ground fault on the load circuit to assure that the ground-fault protection is still functioning. Test and reset buttons are provided for testing.

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13.0 CABINETS, BOXES, AND FITTINGS Conductors Entering Boxes, Cabinets, or Fittings Since conductors can be damaged if they rub against the sharp edges of cabinets, boxes, or fittings, they must be protected from damage where they enter. To protect the conductors, some type of clamp or rubber grommet must be used. The device used must close the hole through which the conductor passes as well as provide protection from abrasion. If the conductor is in a conduit and the conduit fits tightly in the opening, additional sealing is not required. The knockouts in cabinets, boxes, and fittings should be removed only if conductors are to be run through them. However, if a knockout is missing or if there is another hole in the box, the hole or opening must be closed. Covers and Canopies All pull boxes, junction boxes, and fittings shall be provided with covers approved for the purpose. If metal covers are used, they shall be grounded. In completed installations, each outlet box shall have a cover, faceplate, or fixture canopy. Covers of outlet boxes having holes through which flexible cord pendants pass shall be provided with bushings designed for the purpose or shall have smooth, well-rounded surfaces on which the cords may bear.

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14.0 FLEXIBLE CORDS AND CABLES This standard for safe use of flexible cords is one of the most frequently violated electrical standards, particularly in smaller plants. There is a definite need and place for cords, but there is also a temptation to misuse them because they seem to offer a quick and easy way to carry electricity to where it is needed. The basic problem is that flexible cords in general are more vulnerable than the fixed wiring of the building. Therefore, cords should not be used if one of the recognized wiring methods could be used instead. Use of Flexible Cords and Cables Flexible cords and cables shall be approved and suitable for conditions of use and location. The standard lists specific situations in which flexible cords may be used. Flexible cords and cables shall be used only for: a. Pendants (a lamp holder or cord-connector body suspended by a length of cord properly secured and terminated directly above the suspended device); b. Wiring of fixtures; c. Connection of portable lamps or appliances; d. Elevator cables; e. Wiring of cranes and hoists (where flexibility is necessary); f. Connection of stationary equipment to facilitate their frequent interchange (equipment which is not normally moved from place to place, but might be on occasion); g. Prevention of the transmission of noise or vibration. (In some cases vibration might fatigue fixed wiring and result in a situation more hazardous than flexible cord.) h. Appliances where the fastening means and mechanical connections are designed to permit removal for maintenance and repair (e.g. water coolers, exhaust fans); i. Data processing cables approved as a part of the data processing system. Note that all of the above situations involve conditions where flexibility is necessary. Unless specifically permitted by one of these situations, flexible cords and cables may not be used: a. As a substitute for the fixed wiring of the structure; b. Where run through holes in walls, ceilings, or floors; c. Where run through doorways, windows, or similar openings; d. Where attached to building surfaces; or e. Where concealed behind building walls, ceilings, or floors. There is usually not much question about use of the short length of cord which is furnished as part of an approved appliance or tool; there is usually no question about an extension cord used temporarily to permit use of the appliance or tool in its intended manner at some distance from a fixed outlet; but there are questions when the usage is not obviously temporary, and when the 30

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cord is extended to some distant outlet in order to avoid providing a fixed outlet where needed. Flexible cord used in violation of this standard is likely to be damaged by activities in the area; by door or window edges; by staples or fastenings; by abrasion from adjacent materials; or simply by aging. If the conductors become partially exposed over a period of time, there will be danger of shocks, burns, or fire.

14.1 Identification, Splices and Terminations Flexible cords shall be used only in continuous lengths without splice or tap. Hard service flexible cords, No. 12 or larger, may be repaired if spliced so that the splice retains the insulation, outer sheath properties, and usage characteristics of the cord being spliced. Flexible cords shall be connected to devices and fittings so that strain relief is provided which will prevent pull from being directly transmitted to joints or terminal screws.

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15.0 Extension Cords Extension cords provide a convenient temporary method of bringing AC power to a device that is not located near a power source. They are also often involved in electrical code and safety violations. Improper use of extension cords can lead to shock hazards. In addition, use of an undersized extension cord results in an overheated cord and insufficient voltage delivered to the device, thus causing device or cord failure and a fire hazard. Extension Cords MUST NOT: a. Pass through doors or windows. b. Be stapled or attached to a floor, wall, or ceiling. c. Be connected in series. d. Create a tripping or other safety hazard. e. Be unprotected where exposed to foot traffic, moving wheels, or falling debris to minimize tripping hazards and damage to the cords. f. Be in a cable tray that is not intended for power cables. Extension cords must be: a. Must be approved by an NRTL for example: Underwriter Laboratories or SLAC Electrical Equipment Inspection Program (EEIP) and properly maintained with no exposed live parts, exposed ungrounded metal parts, damage, or splices. b. May be used to supply power to appliances under limited conditions. These include: ¾ Temporary situations such as laboratory experiments lasting no longer than 90 days or until the next downtime. ¾ Situations in which permanent rigid or flexible wiring is inappropriate because equipment is moved frequently. ¾ Power tools or other portable appliances used on a transient basis. c. Of sufficient current-carrying capacity to power the device. Current capacity of the cord must be matched to the load. An undersized cord is a fire hazard. d. Made of a heavy-duty or extra-heavy-duty rated cable and must be a continuous length without splices or repairs in the cable. e. Furnished with a ground prong, appropriately sized for the anticipated load, in good condition, free of splices, repairs, and signs of excessive wear. (Equipment grounding conductors that are part of flexible cords or used with fixture wires shall not be smaller than 18 AWG copper and not smaller than the circuit conductors.) Extension cords may be used around construction sites, in damp areas, or in an area where a person may be in direct contact with a solidly grounded conductive object such as working in a vacuum tank, extension cords must be protected by a ground fault circuit interrupter (GFCI) before the cord at a nearby power source. The GFCI can consist of a special circuit breaker, a GFCI outlet, or an extension cord with a built-in GFCI.

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Extension cords are acceptable in combinations with other devices. Some acceptable combinations are: a. Extension cord to device (electrical equipment) b. Power strip to device c. GFCI (with cord) to device d. Direct GFCI dongle to extension cord to device e. Direct GFCI dongle to power strip to device For examples of acceptable and unacceptable combinations of extension cords and power strips, see Figure 1 Extension Cord Use Examples. The examples have been chosen as representative of applications found at SLAC, however acceptable and unacceptable combinations are not limited to the examples.

Figure 1: Examples of Extension Cord Combination Usage

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15.1 Relocatable Power Tap (RPT) or Power Strip A Relocatable Power Tap (RPT) or power strip is a variation of an extension cord, where the cord terminates in a row or grouping of receptacles. Power strips are commonly used in offices to provide multiple receptacles to office equipment. In general, the policies pertaining to extension cords also apply to power strips. Most are rated for 15 amps and should not be overloaded. Good practice and an OSHA interpretation letter suggests that major appliances such as microwaves, refrigerators, space heaters, coffee makers, toaster ovens and other high power loads must be plugged into the wall outlet directly. Power strips are not designed for high power loads such as space heaters, refrigerators and microwave ovens, which can easily exceed the recommended ampere ratings on many power strips. Additional requirements are: ¾ Only UL (or other NRTL) approved device can be used. ¾ A RPT cannot be permanently mounted to any facility surface, except as allowed in 3 below. It may hang from screws or hooks if manufactured with for that purpose with slots or keyholes. ¾ In equipment racks, the preferred method of supplying 120/208-volt utility power to rack-mounted instruments is via a special power strip specifically designed to be rack-installed. 15.2 Surge Protective Device (SPD) Power Strips Surge protection devices (SPDs) are used to protect sensitive electronic equipment such as computers, monitors, scanners and printers, from transient over-voltages. SPDs can be manufactured as corded power strip or a wall mount outlet(s) and may have protected outputs for phone, network, and coaxial cable. Both types are considered as power strips and adding additional cords or power strips would be “daisy chaining”. All surge suppressors have a limited useful life. Metal oxide varistors (MOVs) inside the suppressor slowly degrade over time as they absorb excess energy from the power source. Most surge suppressors will continue to function as a power strip, even though the MOV may have been destroyed by a power spike. This presents two possible dangers: 1) If another power surge should occur, it can damage the equipment or appliances that are plugged into this surge protector. 2) If sufficient voltage passes through the surge protector due to a second power spike, a resistant short may have been formed, allowing heating to occur and a fire to ignite. Surge suppression devices with lights that indicate proper operation should be inspected on a regular basis. Devices without any visual or audible indication, as well as devices manufactured before 1998 should be removed from service and disposed of. Additional requirements are: ¾ All surge protectors or power strips need to be UL approved. Be sure that the product is listed as a TRANSIENT VOLTAGE SURGE SUPPRESSOR. ¾ Use only devices that have an internal circuit breaker. These units will trip the breaker if 34

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the power strip is over loaded or shorted to prevent overheating and fire. ¾ If at any time the surge protector or power strip is hot to the touch remove and replace the unit. The electrical load for this strip should be evaluated for overloading. ¾ Do not locate a surge protector or power strip in any area where the unit would be covered with carpet, furniture, or any other item that will limit or prevent air circulation. ¾ Do not locate a surge protector in a moist environment. NOTE: 1. Minimum energy suppression rating of 1200 joules 2. The larger the minimum energy suppression rating; the better the protection against overheating and fire

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16.0 Selection and Use of Work Practices The work practices used by an employee must be sufficient to prevent electric shock or other injuries that could result from either direct or indirect electrical contact. These work practices must be used when work is performed near or on equipment or circuits that are or may be energized. The work practices used must be consistent with the nature and extent of the electrical hazard.

16.1 Working on Electrical Systems Energized Parts: Only qualified employees are allowed to work on electric parts or equipment that has not been de-energized using approved lockout/tagout procedures. Live parts to which an employee may be exposed will be de-energized before the employee works on or near them, unless: ¾ De-energizing introduces additional or increased hazards. Examples of “additional or increased” hazards include interruption of life support equipment, deactivation of emergency alarm systems, shutdown of fume hood ventilation systems, or removal of illumination for an area. ¾ De-energizing is not possible due to equipment design or operational limitations. Examples include testing that can only be performed with the electrical circuit energized, and work on circuits that form an integral part of a continuous process that would need to be completely shut down in order to permit work on one circuit or piece of equipment. ¾ Live parts operate at less than 50 volts to ground and there is no increased exposure to electrical burns or to explosion due to electric arcs. If de-energizing exposed live parts could add to or increase the hazard or is not possible, then other approved work practices must be used to protect employees who may be exposed to the electrical hazards. The work practices used must protect employees from contact with energized circuit parts directly with any part of their body or indirectly through some other conductive object. The work practices used must be suitable for the conditions under which the work is performed and for the voltages of exposed electric conductors or circuit parts. Working On/Or Near Exposed De-energized Parts: When employees work on exposed deenergized parts or near enough to them to expose the employee to an electrical hazard, then the following safety-related work practices will be followed. ¾ Any conductors or parts of electric equipment that have not been properly locked and/or tagged out must be treated as energized even if these systems have been de-energized. ¾ If the potential exists for an employee to contact parts of fixed electric equipment or circuits that have been de-energized, the circuits energizing the parts must be locked and/or tagged out. Locking and tagging procedures must comply with University of Nevada, Reno’s Lockout/Tagout Program and the requirements outlined in this program. De-energizing Equipment: Safe procedures for de-energizing circuits and equipment will be determined by a qualified worker before the circuit or equipment is de-energized.

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¾ Circuits and equipment to be worked on will be disconnected by the worker from all electric energy sources. Control circuit devices, such as push buttons, selector switches, and interlocks will not be used as the sole means for de-energizing circuits or equipment. Interlocks for electric equipment may not be used as a substitute for lockout and tagging procedures. ¾ Stored electrical energy that might endanger personnel must be released prior to the work. This might include, for example, discharging capacitors, and short-circuiting and grounding high capacitance elements. If the capacitors or associated equipment are handled during this work, they must be treated as energized. ¾ Stored non-electrical energy (for example, hydraulic or pneumatic) in devices that could reenergize electric circuit parts must be blocked or relieved so that circuit parts cannot be accidentally re-energized by the device. ¾ A lock and tag must be placed on each disconnecting means used to de-energize circuits and equipment on which work is to be done. The lock must be attached so as to prevent persons from re-energizing the circuit unless they resort to undue force or the use of tools. ¾ Verification of De-energized Condition: The following requirements must be met before any circuit or equipment is considered de-energized or may be worked on as deenergized. ƒ A qualified person must activate the equipment operating controls or use other methods to verify that the equipment cannot be restarted. ƒ A qualified person must use test equipment to ensure that electrical parts and circuit elements are de-energized. The test must confirm there is no energized condition from induced voltage or voltage backfeed. ƒ Test equipment and instruments must be visually inspected for external defects or damage before being used to verify that the equipment or circuit is de-energized. ƒ When voltage over 600 volts nominal are tested, the test equipment must be checked for proper operation immediately before and after the test. Re-energizing Equipment: In addition to the requirements of the Lockout/Tagout Program, the following requirements must be met, in the order given, before circuits or equipment are reenergized, even temporarily: ¾ A qualified person must conduct tests and visual inspections as necessary to verify that all tools, electrical jumpers, shorts, grounds and other such devices have been removed so that circuits and equipment can be safely energized ¾ Employees potentially exposed to the hazards of re-energizing the circuit must be warned to stay clear ¾ Each employee removes his or her lock(s) and tag(s).

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16.2 Overhead Power Lines When work is to be performed near overhead lines, the lines must be de-energized and grounded. Arrangements must be made with the organization that operates or controls the electric circuits when lines are to be de-energized and grounded. If it is not possible to de-energize and ground overhead lines, then other protective measures, such as guarding, isolating or insulating, must be taken before the work is started. These protective measures must prevent direct contact by the qualified person or indirect contact through conductive materials, tools, or equipment. Only qualified persons from the power distribution company are allowed to install insulating devices on overhead power transmission and distribution lines. All other persons, and any conductive object used by these employees, may not approach closer than the minimum distance specified in Table 1 when working in an elevated location near unguarded, energized overhead lines. Unqualified persons working on the ground are not allowed to bring any conductive object or any insulated object that does not have the proper insulating rating closer to unguarded, energized overhead lines than the distance allowed in Table 2. TABLE 2 Voltage to Ground 50 kV or less Over 50 kV

Minimum Approach Distance 10 feet 10 feet + 4 inches for every 10 kV over 50 kV

Qualified employees working in the vicinity of overhead lines, whether in an elevated position or on the ground, are not allowed to approach or take any conductive object without an approved insulating handle closer to exposed energized parts than allowed in Table 3 unless: ¾ The person is insulated from the energized part by using gloves, with sleeves if necessary, rated for the voltage involved; or ¾ The energized part is insulated from all other conductive objects at a different potential and from the person; or ¾ The person is insulated from all conductive objects at a potential different from the energized part TABLE 3 APPROACH DISTANCES FOR QUALIFIED PERSONS EXPOSED TO ALTERNATING CURRENT Voltage Range (phase-to-phase) Minimum Approach Distance 300 V and less Avoid contact Over 300 V, not over 750 V 1 ft. 0 in. Over 750 V, not over 2 kV 1 ft. 6 in. Over 2 kV, not over 15 kV 2 ft. 0 in. Over 15 kV, not over 37 kV 3 ft. 0 in. Over 37 kV, no over 87.5 kV 3 ft. 6 in. Over 87.5 kV, not over 121 kV 4 ft. 0 in. Over 121 kV, not over 140 kV 4 ft. 6 in.

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16.3 Illumination Employees may not enter spaces containing exposed energized parts unless there is sufficient illumination for them to perform the work safely. Employees may not perform tasks near exposed energized parts where there is lack of illumination or an obstruction that blocks his or her view of the work to be performed. Do not reach blindly into areas that may contain energized parts. 16.4 Confined or Enclosed Work Spaces Employees working in manholes, vaults or similar confined or enclosed spaces that contain exposed energized parts must be provided with, and must use, protective shields, protective barriers, or insulating materials as needed to prevent inadvertent contact with these energized parts. Doors and hinged panels that could swing into an employee and cause him or her to contact exposed energized parts must be secured before work begins. Work performed within confined or enclosed spaces must comply with the University of Nevada, Reno Confined Space Entry Program. 16.5 Conductive Materials and Equipment Conductive materials and equipment that are in contact with any part of an employees’ body must be handled in a manner that will prevent them from contacting exposed energized conductors or circuit parts. If an employee must handle long conductive objects, such as metal ducts, pipes, or rods, in areas with exposed live parts, then insulation, guarding and/or approved materials handling techniques must be used which will minimize the hazard. 16.6 Portable Ladders A portable ladder used where there is potential for contact with exposed energized parts must have nonconductive side rails. 16.7 Conductive Apparel Employees may not wear conductive articles of jewelry and clothing, such as watchbands, bracelets, rings, key chains, necklaces, metalized aprons, cloth with conductive thread, or metal headgear, if they might contact exposed energized parts. 16.8 Housekeeping Housekeeping duties may not be performed close to live parts unless adequate safeguards, such as insulating equipment or barriers, are provided. Electrically conductive cleaning materials, including steel wool, metalized cloth and silicon carbide, as well as conductive liquid solutions, may not be used near energized parts unless procedures are followed which prevent electrical contact.

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17.0 Vehicles and Mechanical Equipment A minimum clearance of 10 feet must be maintained between energized overhead lines and all vehicles or mechanical equipment capable of having parts or its structure elevated (e.g., cranes, mobile scaffolds, elevating platforms, dump trucks, lift trucks, and flatbed trailer cranes). If the voltage of the overhead line is greater than 50 kV, the clearance must be increased by 4 inches for every 10 kV over 50 kV. The clearance requirement may be reduced if: ¾ The vehicle is in transit with its structure lowered. The clearance may be reduced to 4 feet when near energized lines operating at less than 50 kV, or 4 ft. plus 4 inches for every 10 kV over 50 kV. ¾ Insulating barriers are installed to prevent contact with the lines and the barriers are rated for the voltage of the line being guarded. The barrier may not be part of an attachment to the vehicle or its raised structure. The clearance may be reduced to the distance allowed by the design of the insulating barrier. ¾ The equipment is an aerial lift insulated for the voltage involved and the work is performed by a qualified person. The clearance between the uninsulated portion of the lift and the power line may be reduced to the distance given in Table 3. Persons working on the ground are not allowed to contact the vehicle or mechanical equipment or any of its attachments, unless: ¾ The person uses protective equipment rated for the voltage; or ¾ The equipment is located so that no uninsulated part of its structure can provide a conductive path to persons on the ground. Equipment shall not approach closer to the line than 10 feet for voltages less than 50 kV, or 10 feet plus 4 inches for every 10 kV over 50 kV. When any vehicle or mechanical equipment is intentionally grounded, persons may not stand near the point of grounding when there is any possibility of contact with overhead energized lines. Additional precautions (e.g., such as the use of barricades or insulation) must be taken as necessary to protect persons from hazardous ground potentials that can develop within a few feet or more outward from the grounding point.

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18.0 INTERLOCKS Only qualified persons are allowed to bypass electrical safety interlocks, and then only temporarily while qualified person(s) is/are working on the equipment. This work must comply with the specified procedures for working on or near exposed energized parts. The interlock system must be returned to its operable condition when the work is completed.

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19.0 PORTABLE ELECTRICAL EQUIPMENT AND EXTENSION CORDS The following requirements apply to the use of cord-and-plug-connected equipment and flexible cord sets (extension cords): 1. Extension cords may only be used to provide temporary power. 2. Portable cord-and-plug connected equipment and extension cords must be visually inspected before use on any shift for external defects such as loose parts, deformed and missing pins, or damage to outer jacket or insulation, and for possible internal damage such as pinched or crushed outer jacket. Any defective cord or cord-and-plug-connected equipment must be removed from service and no person may use it until it is repaired and tested to ensure it is safe for use. 3. Extension cords must be of the three-wire type. Extension cords and flexible cords must be designed for hard or extra hard usage (for example, types S, ST, and SO). The rating or approval must be visible. 4. Job-made extension cords may only be built by qualified persons, and must be tested and certified prior to use. Job-made extension cords may only be constructed using parts approved for this use. Metal electrical boxes with knockouts, for example, may not be used for job-made extension cords unless approved for that purpose. 5. Personnel performing work on renovation or construction sites using extension cords or where work is performed in damp or wet locations must be provided, and must use, a ground-fault circuit interrupter (GFCI). 6. Portable equipment must be handled in a manner that will not cause damage. Flexible electric cords connected to equipment may not be used for raising or lowering the equipment. 7. Extension cords must be protected from damage. Sharp corners and projects must be avoided. Flexible cords may not be run through windows or doors unless protected from damage, and then only on a temporary basis. Flexible cords may not be run above ceilings or inside or through walls, ceilings or floors, and may not to be fastened with staples or otherwise hung in such a fashion as to damage the outer jacket or insulation. 8. Cords must be covered by a cord protector or tape when they extend into a walkway or other path of travel to avoid creating a trip hazard. 9. Extension cords used with grounding-type equipment must contain an equipmentgrounding conductor (i.e., the cord must accept a three-prong, or grounded, plug). 10. Attachment plugs and receptacles may not be connected or altered in any way that would interrupt the continuity of the equipment grounding conductor. Additionally, these devices may not be altered to allow the grounding pole to be inserted into current connector slots. Clipping the grounding prong from an electrical plug is prohibited. 11. Flexible cords may only be plugged into grounded receptacles. The continuity of the ground in a two-prong outlet must be verified before use with a flexible cord, and it is recommended that the receptacle be replaced with a three-prong outlet. Adapters that interrupt the continuity of the equipment grounding connection may not be used. 12. All portable electric equipment and flexible cords used in highly conductive work locations, such as those with water or other conductive liquids, or in places where 42

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employees are likely to contact water or conductive liquids, must be approved for those locations. 13. Employee's hands must not be wet when plugging and unplugging flexible cords and cord-and-plug connected equipment if energized equipment is involved. 14. If the connection could provide a conducting path to employees hands (for example, if a cord connector is wet from being immersed in water), the energized plug and receptacle connections must be handled only with insulating protective equipment. 15. Locking-type connectors must be properly locked into the connector. 16. Lamps for general illumination must be protected from breakage, and metal shell sockets must be grounded. 17. Temporary lights must not be suspended by their cords unless they have been designed for this purpose. 18. Portable lighting used in wet or conductive locations, such as tanks or boilers, must be operated at no more than 12 volts or must be protected by GFCI’s. Extension cords are considered to be temporary wiring, and must also comply with the section on “Requirements for Temporary Wiring” in this program.

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20.0 Electric Power and Lighting Circuits 20.1 Routine Opening and Closing of Circuits Load rated switches, circuit breakers, or other devices specifically designed as disconnecting means must be used for the opening, reversing, or closing of circuits under load conditions. Cable connectors not of the load-break type, fuses, terminal lugs, and cable splice connections may not be used for opening, reversing, or closing circuits under load conditions except in an emergency.

20.2 Re-closing Circuits after a Protective Device Operates After a circuit is de-energized by a circuit protective device (e.g., circuit breaker or similar), the circuit may not be manually re-energized until it has been determined that the equipment and circuit can be safely energized. The repetitive manual re-closing of circuit breakers or reenergizing circuits by replacing fuses without verifying that the circuit can be safely energized is prohibited. When it can be determined that the overcurrent device operated because of an overload rather than a fault condition, no examination of the circuit or connected equipment is needed before the circuit is re-energized. Overcurrent protection of circuits and conductors may not be modified even on a temporary basis.

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21.0 Test Equipment and Instruments Only qualified persons may perform testing work on electric circuits or equipment. Test instruments and equipment (including all associated test leads, cables, power cords, probes and connectors) must be visually inspected for external defects and damage before the equipment is used. If there is a defect or evidence of damage that might expose an employee to injury, the defective or damaged item must be tagged out of service. The device may not be returned to service until it has been repaired and tested safe for use. Test instruments, equipment, and their accessories must be rated for the circuits and equipment to which they will be connected and designed for the environment in which they will be used.

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22.0 Flammable or Ignitable Materials Where flammable or ignitable materials are present, do not use electric equipment capable of igniting them unless measures are taken to prevent hazardous conditions from developing. Flammable and ignitable materials include, but are not limited to, flammable gases, vapors, or liquids, combustible dust, and ignitable fibers or filings. Equipment that is intrinsically safe for the hazardous condition may be used.

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23.0 Safeguards for Personnel Protection 23.1 Protective Equipment Employees working in areas where there are potential electrical hazards must be provided with, and must use, electrical protective equipment that is appropriate for the specific parts of the body to be protected and for the work to be performed. The department must provide electrical safetyrelated personal protective equipment required by this program at no cost to the employee. 23.2 Workmanship and finish Rubber insulating equipment must meet the American Society of Testing and Materials (ASTM) standards D120-87, D178-93, D1048-93, D1049-93, D1050-90 or D1051-87 as applicable. Manufactured equipment which does not indicate compliance with these ASTM standards must be tested using the a-c and d-c proof tests and related procedures as described in these ASTM standards. Blankets, gloves and sleeves must be produced by seamless process. Insulating blankets, matting, covers, lines, hose, gloves, and sleeves made of rubber must be marked to indicate the class of equipment (e.g., Class 0 equipment must be marked Class 0, Class 1 marked Class 1, and so forth). Non-ozone-resistant equipment other than matting must be marked Type I. Ozoneresistant equipment other than matting shall be marked Type II. Markings must be nonconductive and must be applied in a way that will not damage the insulating qualities. Markings on gloves must be confined to the cuff portion of the glove. Equipment must be free of harmful physical irregularities. Surface irregularities (e.g., indentions, protuberances, or imbedded foreign materials) may be present on rubber goods because of imperfections on forms or molds or because of manufacturing difficulties. These surface irregularities are acceptable under the following conditions: ¾ The indention or part that sticks out blends into a smooth slope when the material is stretched, or ¾ The foreign material remains in place when the insulating material is folded and stretches with the insulating material surrounding it.

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24.0 IN-SERVICE CARE AND USE The department must make certain that electrical protective equipment is maintained in a safe, reliable condition, and that the following requirements are met: ¾ Maximum use voltages for rubber protective equipment must conform to those listed in Table 4. TABLE 4 RUBBER INSULATING EQUIPMENT, MAXIMUM USE VOLTAGE Class of Maximum use voltage1 Equipment a-c --rms 0 1,000 1 7,500 2 17,000 3 26,500 4 36,000 1

The maximum use voltage is the ac voltage (rms) classification of the protective equipment that designates the maximum nominal voltage of the energized system that may be safety worked. The nominal design voltage is equal to the phase-to-phase voltage on multiphase circuits. However, the phase-to-ground potential is considered to be the nominal design voltage: ⇒ If there is no multiphase exposure in a system area and if the voltage is limited to the phaseto-ground potential, or ⇒ If the electrical equipment and devices are insulated or isolated or both so that the multiphase exposure on a grounded wye circuit is removed.

¾ Insulating equipment must be inspected for damage before each day’s use and immediately following any incident that could have caused damage. ¾ An air test must be performed on rubber insulating gloves before use. ¾ Insulating equipment with a hole, tear, puncture or cut, ozone cutting or checking, an embedded foreign object, any change in texture including swelling, softening, hardening, or becoming sticky or inelastic, or any other defect that could damage the insulating property must not be used. ¾ All protective equipment must be used and maintained in accordance with the manufacturer’s instructions. ¾ Insulating equipment found to have defects that might effect its insulating properties must be removed from service until electrical tests have been performed that indicate it is acceptable for continued use. ¾ Where the insulating capability of protective equipment is subject to damage during use, the insulating material shall be protected by an outer covering of leather or other appropriate material. ¾ Rubber insulating equipment must be tested on a schedule as shown in Table 5.

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TABLE 5 RUBBER INSULATING EQUIPMENT TEST INTERVALS Type of Equipment Rubber insulating line hose Rubber insulating covers Rubber insulating blankets Rubber insulating gloves

When to Test Upon indication that the insulating value is suspect Upon indication that insulating value is suspect Before first issue and every 12 months thereafter 1 Before first issue and every 6 months thereafter 1

Rubber insulating sleeves

Before first issue and every 12 months thereafter 1

1

If the insulating equipment has been electrically tested but not issued for service, it may not be placed into service unless it has been electrically tested within the previous 12 months.

Employees must be instructed to clean insulating equipment as needed to remove foreign substances and to store insulating equipment where it is protected from light, temperature extremes, excessive humidity, ozone, and other substances and conditions that may cause damage. Employees must be instructed to visually examine their gloves prior to each use and to avoid handling sharp objects. Protector gloves must be worn over insulating gloves except as follows: ¾ Protector gloves need not be used with Class 0 gloves, under limited-use conditions, where small equipment and parts manipulation require unusually high finger dexterity. ¾ Any other class of glove may be used for similar work without protector gloves if is demonstrated that the possibility of physical damage to the gloves is small and if the class of glove is one class higher than that required for the voltage involved. Insulating gloves that have been used without protector gloves may not be used at a higher voltage until they have been electrically tested. The department must ensure that employees do not use insulating equipment that fails to pass visual inspections or electrical tests except as follows: ¾ Rubber insulating line hose may be used in shorter lengths if the defective portion is cut off. ¾ Rubber insulating blankets may be repaired with a compatible patch as long as the physical and electrical properties equal or exceed those of the blanket. ¾ Rubber insulated blankets may be salvaged by cutting and removing the defective area from the undamaged portion of the blanket if the undamaged area remaining is greater than 22 inches by 22 inches for Class 1, 2, 3 and 4 blankets. ¾ Rubber insulating gloves and sleeves with minor physical defects, such as small cuts, tears or punctures may be repaired by application of a patch with the same electrical and physical properties as the surrounding material. ¾ Rubber insulating gloves and sleeves with minor surface blemishes may be repaired with a compatible liquid compound. 49

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¾ Repairs to gloves are permitted only in the area between the wrist and reinforced edge of the opening. Repaired insulating equipment must be retested before it may be returned to service. These tests must be documented in writing, and indicate the type(s) of test(s) performed, equipment tested (specifically by referencing an applied marking, serial number or similar), date, name of tester, and the results of the tests. These test results must be maintained in a permanent log.

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25.0 GENERAL PROTECTIVE EQUIPMENT & TOOLS Nonconductive head protection must be worn whenever there is danger of head injury from electric shock or burn due to contact with exposed energized parts. Protective equipment for the eyes and/or face must be worn whenever there is danger of injury to the eyes or face from electric arcs, flashes or flying objects resulting from electrical explosion. Insulated tools or handling equipment must be used by employees working near exposed energized conductors or circuit parts if the tools or handling equipment might make contact with such conductors or parts. If the insulating capability of insulated tools or handling equipment is subject to damage, the insulating material must be protected. Protective shields, protective barriers, or insulating materials must be used to protect each employee from shock, burns, or other electrically related injuries while employees are working near exposed energized parts which might be accidentally contacted or where dangerous electric heating or arcing might occur. When normally enclosed live parts are exposed for maintenance or repair, they are to be guarded to protect unqualified persons from contact with the live parts. Fuse handling equipment, insulated for the circuit voltage, must be used to remove or install fuses when the fuse terminals are energized. Ropes and hand lines used near exposed energized parts must be nonconductive.

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26.0 GLOSSARY Other wiring - Installation of other outside conductors on the premises. Optical fiber cable - Installation of optical fiber cable near or with electric wiring. Premises wiring - Installations of electric conductors and equipment in or on buildings or other structures, and in other areas such as yards, parking and other lots, and industrial substations. Qualified persons - those who have received specific training and have demonstrated the skills necessary to work safely on or near exposed energized parts. A person may be qualified to work, for example, on circuits up to 600 volts, but may be unqualified to work on higher voltages. Only qualified persons may place or remove locks and tags on energized electrical systems. Riggers - One that rigs: oil and gas riggers Roustabouts - A laborer employed for temporary or unskilled jobs Unqualified persons - those with little or no electrical safety training or have not been qualified by the University of Nevada, Reno Wiring for connection to supply - Installations of conductors that connect to the supply of electricity. Wye - Electricity - a three-phase, Y-shaped circuit arrangement

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