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ELECTRICAL WORK PRACTICES

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  1. ELECTRICAL WORK PRACTICES Hazardous (Classified) Locations Electrical Safety Work Practices Work Practice Selection and Use Equipment Use Personal Protection Safeguards.

  2. Introduction • This module is based on 29 CFR 1910 Subpart S and covers electrical work requirements designed to minimize potential accidents. The Occupational Safety and Health Administration’s (OSHA) standards were developed to cover electrical system parts an employee would normally use or contact. In general, all equipment should be de-energized before an employee works on it. • Otherwise, protective equipment and insulated tools are required. © 2003 Seton Identification Products

  3. Objectives • At the end of the Electrical Work Practices module, you should be able to: • Identify hazardous locations • Define proper safety related work practices • Define safeguards for personal protection. © 2003 Seton Identification Products

  4. Hazardous (Classified) Locations • Hazardous (classified) locations present a real threat to worker safety. • They are areas where a potential for explosion and fire exist due to the presence of flammable: • Gases • Vapors • Finely pulverized dusts • Ignitable fibers or flyings. • The Hazardous (Classified) Locations section is based on 29 CFR 1910.307. © 2003 Seton Identification Products

  5. Hazardous (Classified) Locations • It presents a description of and the requirements for working in hazardous (classified) locations. • This section covers the topics listed on the left. • 29 CFR 1910.307 is based on the National Electrical Code (NEC), NFPA 70. © 2003 Seton Identification Products

  6. Causes • Hazardous locations can be found in most workplaces. • A hazardous (classified) location may result from the normal processing of certain volatile chemicals, gases, grains, etc., or it may result from accidental failure of storage systems for these materials. © 2003 Seton Identification Products

  7. Causes • It is also possible that a hazardous location may occur when volatile solvents or fluids, used in a normal maintenance routine, vaporize to form an explosive atmosphere. • Each room, section, or area shall be considered individually when determining hazardous classification. © 2003 Seton Identification Products

  8. Precaution • Despite the hazards of a location, every precaution must be taken to guard against ignition of the atmosphere. • Certainly no open flames are permitted in these locations. • Electric equipment capable of igniting flammable materials or gases shall not be used, unless measures are taken to prevent hazardous conditions from developing. • There are many ways in which electrical equipment can act as a source of ignition in a hazardous location: © 2003 Seton Identification Products

  9. Precaution • Switches, circuit breakers, motor starters, contactors, plugs, and receptacles all release arcs and sparks as contacts open and close during normal operation • Lighting fixtures and motors are classified as "heat producing". They will become a source of ignition if their surface temperature exceeds the ignition temperature of the flammable material or gas • An abnormality or failure in an electrical system, such as the failure of insulation, can release sparks, arcs, or heat. © 2003 Seton Identification Products

  10. Wiring Installation • It is important to have an awareness of the problems that electrical equipment and wiring create when they are located in hazardous (classified) locations because several OSHA standards require the installation of electrical wiring and equipment in these locations. • Most of these locations are defined in the "Hazardous (Classified) Locations" module available from the "Hazardous Materials" selection on the main menu. © 2003 Seton Identification Products

  11. Electrical Safety Work Practices- Introduction • Any location with electrical equipment creates dangerous working conditions. • OSHA Safety Related Work Practice standards for general industry were developed to protect employees from the electrical hazards to which they may be exposed even when equipment is in compliance with the installation requirements of Subpart S. Electrical. © 2003 Seton Identification Products

  12. Electrical Safety Work Practices- Introduction • OSHA Safety-Related Work Practice standards for general industry, 1910.331 - .399, are performance-oriented regulations that complement the existing electrical installation standards © 2003 Seton Identification Products

  13. Electrical Safety Work Practices- Introduction • These work-practice standards include requirements for: • Work performed on or near exposed energized and de-energized parts of electric equipment • Use of electrical protective equipment • Safe use of electric equipment. • The topics covered are listed to the left © 2003 Seton Identification Products

  14. Electrical Safety Work Practices - Scope • The provisions of 1910.331 designate the scope of safety-related work practices based on an employee’s classification as qualified or unqualified. • A qualified employee is an employee with training in avoiding electrical hazards when working near exposed energized parts while an unqualified employee has little or no training in this area. • Both qualified and unqualified employees are covered by the standard when working on, near, or with the following installations: © 2003 Seton Identification Products

  15. Electrical Safety Work Practices - Scope • Premises Wiring - Installations of electric conductors and equipment within or on buildings or other structures, and on other premises such as yards, carnivals, parking lots, and industrial substations • Wiring for Connections to Supply - Installations of conductors that connect to the supply of electricity • Other Wiring - Installations of other outside conductors on the premises • Optical Fiber Cable - Installations of optical fiber cable where such installations are made along with electric conductors. © 2003 Seton Identification Products

  16. Electrical Safety Work Practices - Scope • Any unqualified employee working on, near, or with the following installations are covered by standard 1910.331: • Generation, transmission, and distribution installations located in buildings used for such purposes or located outdoors • Communications installations containing communications equipment to the extent that the work is covered under OSHA standard 1910.268 © 2003 Seton Identification Products

  17. Electrical Safety Work Practices - Scope • Installations in vehicles such as ships, watercraft, railway rolling stock, aircraft, or automotive vehicles other than mobile homes and recreational vehicles • Railway installations used for generation, transformation, transmission, or distribution of power used exclusively for operation of rolling stock or installations of railways used exclusively for signaling and communication purposes. • Qualified employees are not covered by standard 1910.331 when working on the above four installations. © 2003 Seton Identification Products

  18. Electrical Safety Work Practices - Descriptions • Employees covered by standard 1910.331 must follow the safe work practices listed here: • Keep a prescribed distance from exposed energized lines • Avoid the use of electric equipment when the employee or the equipment is wet • Lockout and tag equipment which is de-energized for maintenance © 2003 Seton Identification Products

  19. Electrical Safety Work Practices - Descriptions • Use electrical protective devices such as: • Rubber gloves and rubber mats to insulate against live parts • Live-line tools which provide a means of manipulating live parts from a distance. Live-line tools must also insulate workers from live parts. • The protective capabilities of equipment is dependent on proper manufacturing and maintenance. © 2003 Seton Identification Products

  20. Differentiation with CFR 1910.147 • It is important to understand the distinction between OSHA Standards 1910.331 - .399 and OSHA Standard 1910.147, Control of Hazardous Energy (Lockout/Tagout). • The lockout/tagout standard (1910.147) helps safeguard employees from hazardous energy while they are performing servicing or maintenance on machines and equipment. © 2003 Seton Identification Products

  21. Differentiation with CFR 1910.147 • Standard 1910.147 covers electrical energy sources, but it specifically excludes "exposure to electrical hazards from work on, near, or with conductors or equipment in electrical utilization installations," which is covered by Subpart S, Electrical. • Thus, the lockout/tagout standard does not cover electrical hazards associated with conductors, and only defines requirements for electrical machinery and equipment that are covered by this lockout standard. © 2003 Seton Identification Products

  22. Training • 29 CFR 1910.332 describes training requirements for employees who face a risk of electric shock that is not reduced to a safe level by the electrical installation requirements of 1910.303 - .308. • Employees in occupations exposed to electric shock risk must be trained. Click on the term below to see a list of occupations that require such training. • Occupations Exposed to Electric Shock Risk © 2003 Seton Identification Products

  23. Training • With the exception of electricians and welders, workers do not need to be trained if their work or the work of those they supervise 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. • The training required by this section shall be of the classroom or on-the-job type. The degree of training provided shall be determined by the risk to the employee. © 2003 Seton Identification Products

  24. Training • Employees shall be trained in safety-related work practices required by 1910.331-.355 that pertain to their respective job assignments. • In addition, unqualified employees who are covered by the scope of this standard shall also be trained in any electrically related safety practices not specifically addressed by 1910.331 - .335, but which are necessary for their safety. © 2003 Seton Identification Products

  25. Training • At a minimum, qualified persons shall be trained in and familiar with the: • Skills and techniques necessary to distinguish exposed live parts from other parts of electric equipment • Skills and techniques necessary to determine the nominal voltage of exposed live parts • Clearance distances specified in this standard and the corresponding voltages to which the qualified person will be exposed. © 2003 Seton Identification Products

  26. Quiz Question: • Hazardous (classified) locations are areas where employees are in danger of electric shock. • True • False © 2003 Seton Identification Products

  27. Quiz Question: • The lockout/tagout standard (1910.147) covers electrical hazards associated with conductors and equipment. • True • False © 2003 Seton Identification Products

  28. Selection and Use of Work Practices - Introduction • The Selection and Use of Work Practices section, based on standard 1910.333, covers employees working on or near the topics listed on the left. • In general, safety-related work practices shall be used to prevent employees from being shocked by equipment which may be energized. • Specific safety-related work practices shall be consistent with the associated electrical hazards as described in this section. © 2003 Seton Identification Products

  29. Exposed De-energized Parts • Live parts to which an employee may be exposed shall be de-energized before the employee works on or near them. However, de-energizing is not required if it: • Introduces additional or increased hazards • Is infeasible due to equipment design or operational limits • Contains live parts that operate at less than 50 volts to ground and does not increase the risk of electrical burns or explosion due to electric arcs. © 2003 Seton Identification Products

  30. Exposed De-energized Parts • While any employee is exposed to contact with de-energized fixed electric equipment or circuits, the circuits energizing the parts shall be locked out, tagged, or both. • De-energized conductors and electric equipment parts that have not been tagged shall be treated as energized parts. • Click below to review the proper lock out/tagging procedures. • Lock Out/Tagging Procedures © 2003 Seton Identification Products

  31. Exposed Energized Parts • Sometimes equipment cannot be de-energized due to operational limits, equipment design, or risk of increased hazards. • Only qualified persons may work on electric circuit parts or equipment that have not been de-energized under the procedures of standard 1910.333. © 2003 Seton Identification Products

  32. Exposed Energized Parts • Qualified persons shall be capable of working safely on energized circuits and shall be familiar with: • Proper use of special precautionary techniques • Personal protective equipment • Insulating and shielding materials • Insulated tools. • To protect employees working on exposed live parts, safety-related work practices shall be used. Such work practices protect employees against contact with energized circuit parts directly with any part of their body or indirectly through a conductive object. © 2003 Seton Identification Products

  33. Exposed Energized Parts • If work is to be performed near overhead lines, the lines shall be de-energized and grounded, unless other protective measures are provided before work is started. • If the lines are to be de-energized, arrangements to de-energize and ground the lines shall be made with the operator or controller of the electric circuits involved. • If protective measures such as guarding, isolating, or insulating are provided, these precautions shall prevent employees from contacting lines directly with any body part or conductive materials, tools, or equipment. • The closest an unqualified person may come to an unguarded, energized overhead line is 10 feet plus 4 inches for every 10 kV over 50 kV. This rule also applies to any conductive material with which he or she is in contact. © 2003 Seton Identification Products

  34. Exposed Energized Parts • The closest a qualified person and the longest conductive material he or she possesses may come to an unguarded, energized overhead line is designated in Table S-5 of 1910.333(c)(3)(ii), unless certain insulation requirements are met. • The closest any part of a vehicle or mechanical equipment that is capable of being elevated may come to an unguarded, energized overhead line is 10 feet plus 4 inches for every 10 kV over 50 kV. However, the standard outlines situations where the clearance can be reduced for elevated equipment. © 2003 Seton Identification Products

  35. Exposed Energized Parts • Energized parts, conductive materials, and equipment that are in contact with any part of an employee's body shall be handled in a manner that will prevent them from contacting exposed energized conductors or circuit parts. • If an employee must handle long dimensional conductive objects (such as ducts and pipes) in areas with exposed live parts, the employer shall institute work practices (such as the use of insulation, guarding, and material handling techniques) which will minimize the hazard. © 2003 Seton Identification Products

  36. Exposed Energized Parts • Conductive articles of jewelry and clothing may not be worn if they might contact exposed energized parts, unless they are rendered non-conductive by covering, wrapping, or other insulating means. © 2003 Seton Identification Products

  37. Exposed Energized Parts • Where live parts present an electrical contact hazard, employees may not perform housekeeping duties at distances close enough for possible contact unless adequate safeguards (such as insulating equipment or barriers) are provided. • Electrically conductive cleaning materials may not be used in proximity to energized parts unless procedures are followed which will prevent electrical contact. © 2003 Seton Identification Products

  38. Exposed Energized Parts • If a portable ladder is to be used where the employee or ladder could contact exposed energized parts, the ladder shall have non-conductive siderails. • Only a qualified person following the requirements of this section may defeat an electrical safety interlock, and then only temporarily while he or she is working on the equipment. • The interlock system shall be returned to its operable condition when the work is completed. © 2003 Seton Identification Products

  39. Exposed Energized Parts • Employees may not enter spaces containing exposed energized parts unless illumination is provided that enables the employees to perform the work safely. • Where lack of illumination or an obstruction precludes observation of the work to be performed, employees may not perform tasks near exposed energized parts. • Employees may not reach blindly into areas which may contain energized parts. © 2003 Seton Identification Products

  40. Quiz Question: • De-energized equipment must be locked out. • True • False © 2003 Seton Identification Products

  41. Quiz Question: • The closest an unqualified employee may come to an overhead line is 10 feet plus: • 6 inches for every 10 kV over 50 kV • 8 inches for every 10 kV over 50 kV • 10 inches for every 10 kV over 50 kV • 4 inches for every 10 kV over 50 kV © 2003 Seton Identification Products

  42. Equipment Use - Introduction • The Equipment Use section is based on 29 CFR 1910.334. It describes the topics listed on the left. • Proper use of equipment is at the core of maintaining worker and equipment safety. • Equipment that is transported and used in different locations is susceptible to improper use, because each new location presents different hazards that must be assessed. © 2003 Seton Identification Products

  43. Portable Electric Equipment • Portable electric equipment requirements apply to cord- and plug-connected equipment including flexible cord sets (extension cords). • The requirements include the following. © 2003 Seton Identification Products

  44. Portable Electric Equipment • Portable cord- and plug-connected equipment and flexible cord sets shall be visually inspected for external defects and for evidence of possible internal damage before use on any shift. If the equipment and extension cords remain connected once they are put in place and are not exposed to damage, they do not need to be visually inspected until they are relocated. Defective or damaged items shall be removed from service until repaired. © 2003 Seton Identification Products

  45. Portable Electric Equipment • Portable equipment shall be handled carefully to prevent damage. Flexible electric equipment cords may not be used for raising or lowering the equipment nor should they be fastened with staples or otherwise hung in such a fashion that could damage the outer jacket or insulation. • Locking-type connectors shall be properly secured after connection. © 2003 Seton Identification Products

  46. Portable Electric Equipment • 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. • Employees' hands may not be wet when plugging and unplugging flexible cords and cord- and plug-connected equipment, if energized equipment is involved. © 2003 Seton Identification Products

  47. Portable Electric Equipment • Energized plug and receptacle connections may be handled only with insulating protective equipment if the connection could provide a conducting path to the employee's hand. © 2003 Seton Identification Products

  48. Portable Electric Equipment • When a flexible cord is used with grounding-type equipment, the cord shall contain an equipment grounding conductor. • Attachment plugs and receptacles may not be connected or altered in a manner which would prevent proper continuity of the equipment grounding conductor at the point where plugs are attached to receptacles. Additionally, these devices may not be altered to allow the grounding pole of a plug to be inserted into slots intended for connection to the current-carrying conductors. • Adapters which interrupt the continuity of the equipment grounding connection may not be used. © 2003 Seton Identification Products

  49. Test Instruments and Equipment • Testing instruments and equipment are subject to damage much like other portable equipment. • Since test instruments are utilized in different work environments, they are prone to misuse. • The following regulations for their use and handling were developed. • Only qualified persons may perform testing work on electric circuits or equipment. © 2003 Seton Identification Products

  50. Test Instruments and Equipment • Test instruments and equipment and all associated test leads, cables, power cords, probes, and connectors shall 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 shall be removed from service, and it will not be used until necessary repairs and tests to render the equipment safe have been made. • Test instruments and equipment and their accessories shall be rated for the circuits and equipment to which they will be connected and shall be designed for the environment in which they will be used. © 2003 Seton Identification Products