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Best Practices in Handling Electricity on Construction Worksites Instructor: Frank Perrino.

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Presentation on theme: "Best Practices in Handling Electricity on Construction Worksites Instructor: Frank Perrino."— Presentation transcript:

1 Best Practices in Handling Electricity on Construction Worksites Instructor: Frank Perrino

2 1926 - Sub Part K Electrical NFPA 78

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4 Sub Part K Electrical - Installation Safety Requirements (a) Covered. Sections 1926.402 through 1926.408 contain installation safety requirements for electrical equipment and installations used to provide electric power and light at the jobsite. –These sections apply to installations, both TEMPORARY and PERMANENT, used on the jobsite; but these sections do not apply to existing permanent installations that were in place before the construction activity commenced.

5 1926.402 (b) Not covered –Sections 1926.402 through 1926.408 do not cover installations used for the generation, transmission, and distribution of electric energy, including related communication, metering, control, and transformation installations. (However, these regulations do cover portable and vehicle-mounted generators used to provide power for equipment used at the jobsite.) See Subpart V of this Part for the construction of power distribution and transmission lines. Transmission Lines not covered

6 1926.403(a) Approval –All electrical conductors and equipment shall be approved. UNDERWRITERS LABORATORIES ENCLOSED SWITCH Issue AK 3225 LISTED 1910.303(a) NEC Article 110-2

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8 –(b)(1)(i) Suitability for installation and use in conformity with the provisions of this subpart - evidenced by listing, labeling, or certification for that identified purpose. –(b)(1)(ii) Mechanical strength and durability. –(b)(1)(iii) Electrical insulation. –(b)(1)(iv) Heating effects under conditions of use. –(b)(1)(v) Arcing effects. –(b)(1)(vi) Classification by type, size, voltage, current capacity, specific use. –(b)(1)(vii) Other factors which contribute to the practical safeguarding of employees using or likely to come in contact with the equipment. 403(b)(1) Examination. The employer shall ensure that electrical equipment is free from recognized hazards that are likely to cause death or serious physical harm to employees. 1910.303(b)(1) NEC Article 110-3

9 UL Label 1926.403(b)(2) - Installation and use. Listed, labeled, or certified equipment shall be installed and used in accordance with instructions included in the listing, labeling, or certification. 1910.303(b)(2) NEC Article 110-3b

10 1926.403 (d)(1) Mounting. Electric equipment shall be firmly secured to the surface on which it is mounted. Wooden plugs driven into holes in masonry, concrete, plaster, or similar materials shall not be used. NEC Article 110-133a

11 1926.403(e) Splices –Conductors shall be spliced or joined with splicing devices designed for the use or by brazing, welding, or soldering with a fusible metal or alloy. Soldered splices shall first be so spliced or joined as to be mechanically and electrically secure without solder and then soldered. –All splices and joints and the free ends of conductors shall be covered with an insulation equivalent to that of the conductors or with an insulating device designed for the purpose. 1910.303(c) NEC Article 110-14b

12 1926.403(g) Marking –Electrical equipment shall not be used unless the manufacturer's name, trademark, or other descriptive marking by which the organization responsible for the product may be identified is placed on the equipment and unless other markings are provided giving voltage, current, wattage, or other ratings as necessary. The marking shall be of sufficient durability to withstand the environment involved. SQUARE D Heavy Duty Safety Switch 30 AMP 600 V.AC 20 H.P. MAX. RATING 3 PH DANGER HAZARD OF ELECTRICAL SHOCK OR BURN. SEE INSTRUCTIONS INSIDE DOOR B-40274-855-01 1910.303(e) NEC Article 110-21

13 1926.403(h) Identification of disconnecting means and circuits. –Each service, feeder, and branch circuit, at its disconnecting means or overcurrent device, shall be legibly marked to indicate its purpose, unless located and arranged so the purpose is evident. These markings shall be of sufficient durability to withstand the environment involved. 1910.303(f) NEC Article 110-22

14 MARKINGS

15 1926.403(i)(2) Guarding of live parts. –(i)(2)(i) 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 cabinets or other forms of enclosures 1910.303(g)(2) NEC Article 110-27a

16 Neutral Hot 1926.404(a)(2)ReversePolarity 1910.304(a)(2) NEC Article 200-11

17 1926.404(e)(1)(iv) –Location in or on premises. Overcurrent devices shall be readily accessible. Overcurrent devices shall not be located where they could create an employee safety hazard by being exposed to physical damage or located in the vicinity of easily ignitable material. 1910.304(e)(1)(iv) NEC Article 240-24

18 1926.404 (b)(1)(i) General. –The employer shall use either ground fault circuit interrupters as specified in paragraph (b)(1)(ii) of this section OR an assured equipment grounding conductor program as specified in paragraph (b)(1)(iii) of this section to protect employees on construction sites. These requirements are in addition to any other requirements for equipment grounding conductors. Only GFCI in General Industry is pools and decorative fountains NOT Drinking fountains NEC Article 305-6

19 When do we test?? Monthly

20 1926.404(b)(1)(ii) Ground-fault circuit interrupters. – All 120-volt, single-phase 15- and 20-ampere receptacle outlets on construction sites, which are not a part of the permanent wiring of the building or structure and which are in use by employees, shall have approved ground-fault circuit interrupters for personnel protection. Common Name “Pig Tail” * The NEC has included the 30 ampere receptacle outlet NEC Article 305-6a,15,20,30 amp outlets and not limited to construction sites

21 1926.404(b)(1)(iii) Assured equipment grounding conductor program. –The employer shall establish and implement an assured equipment grounding conductor program on construction sites covering all cord sets, receptacles which are not a part of the building or structure, and equipment connected by cord and plug which are available for use or used by employees. NEC Article 305-6b only permitted for other than 125 v, 15,20,30 amp

22 1926.404(b)(1)(iii) Assured equipment grounding conductor program shall comply with the following minimum requirements: (b)(1)(iii)(A) A written description of the program (b)(1)(iii)(B) designate one or more competent persons (b)(1)(iii)(C) visually inspected before each day's use (b)(1)(iii)(D) Perform tests on all cord sets –for continuity and shall be electrically continuous –for correct attachment of the equipment grounding conductor NEC Article 305-b2

23 (b)(1)(iii)(E) All required tests shall be performed: –(b)(1)(iii)(E)(1) Before first use; –(b)(1)(iii)(E)(2) Before equipment is returned to service following any repairs; –(b)(1)(iii)(E)(3) Before equipment and after any incident –(b)(1)(iii)(E)(4) At intervals not to exceed 3 months - 6 months –(b)(1)(iii)(F) Shall not use equipment which has not met the requirements of this paragraph (b)(1)(iii) of this section. –(b)(1)(iii)(G) Tests performed as required in this paragraph shall be recorded. Identify each receptacle, cord set, and cord- and plug-connected equipment that passed the test. Indicate the last date it was tested or the interval for which it was tested. Record shall be kept by means of logs, color coding, or other effective means Maintained until replaced by a more current record. Record shall be made available on the jobsite for inspection by the Assistant Secretary and any affected employee. 1926.404(b)(1)(iii) Assured equipment grounding conductor program shall comply with the following minimum requirements: (cont)

24 1926.404(f)(6) Grounding path. –The path to ground from circuits, equipment, and enclosures shall be permanent and continuous. 1910.304(f)(4) 1999 NEC Article 250-2b,c,d NEC Article 250-51 Previous NEC editions

25 1926.405(a)(2)(ii) General requirements for temporary wiring - –(C)Receptacles for uses other than temporary lighting shall not be installed on branch circuits which supply temporary lighting. Receptacles shall not be connected to the same ungrounded conductor of multiwire circuits which supply temporary lighting. NEC Article 305-4d

26 1926.405(a)(2)(ii)(E) –All lamps for general illumination shall be protected from accidental contact or breakage. 1910.305(a)(2)(iii)(F) NEC Article 305-4f

27 1926.405(a)(2)(ii)(F) Temporary lights shall not be suspended by their electric cords unless cords and lights are designed for this means of suspension.

28 1926.405(a)(2)(ii)(I) –Flexible cords and cables shall be protected from damage. Sharp corners and projections shall be avoided. 1910.305(a)(1)(iii)(G) NEC Article 305-4h

29 1926.405(a)(2)(ii)(I) (CONT) –Flexible cords and cables shall be protected from damage. Sharp corners and projections shall be avoided. Flexible cords and cables may pass through doorways or other pinch points, if protection is provided to avoid damage.

30 1926.405(a)(2)(ii)(J) –Extension cord sets used with portable electric tools and appliances shall be of three-wire type and shall be designed for hard or extra- hard usage. Flexible cords used with temporary and portable lights shall be designed for hard or extra-hard usage. NOTE: The National Electrical Code, ANSI/NFPA 70, in Article 400, Table 400-4, lists various types of flexible cords, some of which are noted as being designed for hard or extra-hard usage. Examples of these types of flexible cords include hard service cord (types S, ST, SO, STO) and junior hard service cord (types SJ, SJO, SJT, SJTO). NEC Article 305-4b&c

31 1926.405(b)Cabinets, boxes, and fittings. –(b)(1) Conductors entering boxes, cabinets, or fittings. Conductors entering boxes, cabinets, or fittings shall be protected from abrasion, and openings through which conductors enter shall be effectively closed. –Unused openings in cabinets, boxes, and fittings shall also be effectively closed. 1910.305(a)(1) NEC Article 110-12a 1910.305(b)

32 TESTERS

33 ELECTRICAL HAZARD RECOGNITION

34 Electrical incidents Electricity has become essential to modern life Because it is such a familiar part of our surroundings, it’s often not treated with the respect it deserves Safety and health programs must address electrical incidents and the variety of ways electricity becomes a hazard In general, employees must not work near any part of an electrical power circuit unless protected The following hazards are the most frequent cause of electrical injuries

35 Most frequently cited electrical standards Branch circuits - Ground fault protection/ Assured equipment grounding conductor program Grounding path Ground-fault circuit interrupters Equipment installation and use Worn/frayed electric cords or cables

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47 Examples of Equipment That Can Contact Power Lines –Aluminum paint rollers –Backhoes –Concrete pumpers –Cranes –Long-handled cement finishing floats –Metal building materials –Metal ladders –Raised dump truck beds –Scaffolds

48 Most frequently cited electrical standards Branch circuits - Ground fault protection/ Assured equipment grounding conductor program Grounding path Ground-fault circuit interrupters Equipment installation and use Worn/frayed electric cords or cables

49 Questions? Muchas Gracias Frank Perrino OSHA Training Institute perrino.frank@dol.gov Tel.: 847 759 7744

50 Contact with power lines Am I In Danger? –Overhead and buried power lines at your site are especially hazardous because they carry extremely high voltage –Fatal electrocution is the main risk –Burns and falls from elevation are also hazards –Using tools and equipment that can contact power lines increases the risk Overhead power lines are un-insulated and can carry tens of thousands of volts, making them extremely dangerous to employees who work in their vicinity.

51 Contact with power lines (cont’d) Examples of Equipment That Can Contact Power Lines –Aluminum paint rollers –Backhoes –Concrete pumpers –Cranes –Long-handled cement finishing floats –Metal building materials –Metal ladders –Raised dump truck beds –Scaffolds Crane fire

52 Look for overhead power lines and buried power line indicators Post warning signs Contact utilities for buried power line locations Stay at least 10 feet Unless you know otherwise, assume lines are energized De-energize and ground lines when working near them Other protective measures include guarding or insulating the lines Use non-conductive wood or fiberglass ladders when working near power lines How do I avoid hazards?

53 Lack of ground fault protection Use ground-fault circuit interrupters (GFCIs) on all 120-volt, single-phase, 15- and 20-ampere receptacles Follow manufacturers' recommended testing procedure to insure GFCI is working correctly Use double-insulated tools and equipment Use tools and equipment according to the instructions Inspect all electrical equipment before use These receptacles are not protected by a GFCI. If there is no AEGCP on this jobsite this would be a violation.

54 Lack of ground fault protection Use ground-fault circuit interrupters (GFCIs) on all 120-volt, single-phase, 15- and 20-ampere receptacles Follow manufacturers' recommended testing procedure to insure GFCI is working correctly Use double-insulated tools and equipment Use tools and equipment according to the instructions Inspect all electrical equipment before use These receptacles are not protected by a GFCI. If there is no AEGCP on this jobsite this would be a violation.

55 Path to ground missing or discontinuous Ground all power supply systems, electrical circuits, and electrical equipment Inspect electrical systems to insure that the path to ground is continuous Inspect all electrical equipment before use. Take any defective equipment out of service Do not remove ground prongs from cord- and plug-connected equipment or extension cords Use double-insulate tools Ground all exposed metal parts of equipment Removing the ground pin from a plug to fit an ungrounded outlet not only means your work area is unsafe, but makes the cord unfit for future work where there is grounding.

56 Path to ground missing or discontinuous Ground all power supply systems, electrical circuits, and electrical equipment Inspect electrical systems to insure that the path to ground is continuous Inspect all electrical equipment before use. Take any defective equipment out of service Do not remove ground prongs from cord- and plug-connected equipment or extension cords Use double-insulate tools Ground all exposed metal parts of equipment Removing the ground pin from a plug to fit an ungrounded outlet not only means your work area is unsafe, but makes the cord unfit for future work where there is grounding.

57 Equipment not used in manner prescribed Common Examples of Misused Equipment –Using multi-receptacle boxes designed to be mounted by fitting them with a power cord and placing them on the floor –Fabricating extension cords with ROMEX® wire –Using equipment outdoors labeled for use only in dry, indoor locations –Attaching ungrounded, two-prong adapter plugs to three-prong cords and tools –Using circuit breakers or fuses with the wrong rating for over-current protection –Using modified cords or tools –Using cords or tools with worn insulation or exposed wires This "handy box" is being improperly used as an extension cord receptacle. It is made to be permanently mounted.

58 Equipment not used in manner prescribed Common Examples of Misused Equipment –Using multi-receptacle boxes designed to be mounted by fitting them with a power cord and placing them on the floor –Fabricating extension cords with ROMEX® wire –Using equipment outdoors labeled for use only in dry, indoor locations –Attaching ungrounded, two-prong adapter plugs to three-prong cords and tools –Using circuit breakers or fuses with the wrong rating for over-current protection –Using modified cords or tools –Using cords or tools with worn insulation or exposed wires This "handy box" is being improperly used as an extension cord receptacle. It is made to be permanently mounted.

59 Equipment not used in manner prescribed (cont’d) How Do I Avoid Hazards? –Use only equipment that is approved to meet OSHA standards –Use all equipment according to the manufacturer's instructions –Do not modify cords or use them incorrectly –Be sure equipment that has been shop fabricated or altered is in compliance. Strain relief damaged Flexible cord damaged by door or window edges, staples fastenings, abrasion from adjacent materials, or simply by aging

60 Lack of ground fault protection Use ground-fault circuit interrupters (GFCIs) on all 120-volt, single-phase, 15- and 20-ampere receptacles Follow manufacturers' recommended testing procedure to insure GFCI is working correctly Use double-insulated tools and equipment Use tools and equipment according to the instructions Inspect all electrical equipment before use These receptacles are not protected by a GFCI. If there is no AEGCP on this jobsite this would be a violation.

61 Lack of ground fault protection Use ground-fault circuit interrupters (GFCIs) on all 120-volt, single-phase, 15- and 20-ampere receptacles Follow manufacturers' recommended testing procedure to insure GFCI is working correctly Use double-insulated tools and equipment Use tools and equipment according to the instructions Inspect all electrical equipment before use These receptacles are not protected by a GFCI. If there is no AEGCP on this jobsite this would be a violation.

62 Path to ground missing or discontinuous Ground all power supply systems, electrical circuits, and electrical equipment Inspect electrical systems to insure that the path to ground is continuous Inspect all electrical equipment before use. Take any defective equipment out of service Do not remove ground prongs from cord- and plug-connected equipment or extension cords Use double-insulate tools Ground all exposed metal parts of equipment Removing the ground pin from a plug to fit an ungrounded outlet not only means your work area is unsafe, but makes the cord unfit for future work where there is grounding.

63 Path to ground missing or discontinuous Ground all power supply systems, electrical circuits, and electrical equipment Inspect electrical systems to insure that the path to ground is continuous Inspect all electrical equipment before use. Take any defective equipment out of service Do not remove ground prongs from cord- and plug-connected equipment or extension cords Use double-insulate tools Ground all exposed metal parts of equipment Removing the ground pin from a plug to fit an ungrounded outlet not only means your work area is unsafe, but makes the cord unfit for future work where there is grounding.

64 Equipment not used in manner prescribed (cont’d) How Do I Avoid Hazards? –Use only equipment that is approved to meet OSHA standards –Use all equipment according to the manufacturer's instructions –Do not modify cords or use them incorrectly –Be sure equipment that has been shop fabricated or altered is in compliance. Strain relief damaged Flexible cord damaged by door or window edges, staples fastenings, abrasion from adjacent materials, or simply by aging

65 Equipment not used in manner prescribed (cont’d) How Do I Avoid Hazards? –Use only equipment that is approved to meet OSHA standards –Use all equipment according to the manufacturer's instructions –Do not modify cords or use them incorrectly –Be sure equipment that has been shop fabricated or altered is in compliance. Strain relief damaged Flexible cord damaged by door or window edges, staples fastenings, abrasion from adjacent materials, or simply by aging

66 Equipment not used in manner prescribed (cont’d) How Do I Avoid Hazards? –Use only equipment that is approved to meet OSHA standards –Use all equipment according to the manufacturer's instructions –Do not modify cords or use them incorrectly –Be sure equipment that has been shop fabricated or altered is in compliance. Strain relief damaged Flexible cord damaged by door or window edges, staples fastenings, abrasion from adjacent materials, or simply by aging

67 Improper use of extension and flexible cords How Do I Avoid Hazards? –Use factory-assembled cord sets –Use only 3-wire type extension cords –Cords must be marked with a designation code for hard or extra- hard usage –Cords, connection devices, and fittings must be equipped with strain relief –Remove cords from receptacles by pulling on the plugs, not the cords –Continually audit cords on-site These cords are improperly wired directly to the electrical circuit, are not protected by a GFCI, and are two-wire cords that are not grounded and not rated for hard- or extra-hard service.

68 Improper use of extension and flexible cords How Do I Avoid Hazards? –Use factory-assembled cord sets –Use only 3-wire type extension cords –Cords must be marked with a designation code for hard or extra- hard usage –Cords, connection devices, and fittings must be equipped with strain relief –Remove cords from receptacles by pulling on the plugs, not the cords –Continually audit cords on-site These cords are improperly wired directly to the electrical circuit, are not protected by a GFCI, and are two-wire cords that are not grounded and not rated for hard- or extra-hard service.

69 Questions?

70 Electrical incidents Electricity has become essential to modern life Because it is such a familiar part of our surroundings, it’s often not treated with the respect it deserves Safety and health programs must address electrical incidents and the variety of ways electricity becomes a hazard In general, employees must not work near any part of an electrical power circuit unless protected The following hazards are the most frequent cause of electrical injuries


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