2015 NFPA 70E Arc Flash Overview

Transcription

1 2015 NFPA 70E Arc Flash Overview Presented by: Jay Jamali, CSP, CHMM, CHCM Oakland Road San Jose, CA

2 Causes SLIDE-2

3 Arc Flash SLIDE-3 35,000 F Molten Metal Pressure Waves Sound Waves Copper Vapor: Solid to Vapor Expands by 67,000 times Shrapnel Hot Air-Rapid Expansion Intense Light

4 NFPA 70E SLIDE-4 OSHA requested National Fire Protection Association (NFPA) to develop a Standard for Electrical Safety in the Workplace (70E) which requires: Electrical Safety Program (ESP) Electrical safety procedures Electrical preventative maintenance program Training and job briefing Risk assessment Shock and arc boundary Personal Protective Equipment (PPE) Lock Out Tag Out (LOTO) Emergency procedures Contractors, house keeping Labeling Energized work permit Illumination, testing, audit Special equipment, insulated tools and barriers

5 NFPA 70E SLIDE-5 This standard applies to hazards associated with electrical energy during activities such as: Installation (conductors and equipment that connect to the supply of electricity) Inspection, Operation, Maintenance, and Demolition of electric conductors, electric equipment, signaling and communications conductors and equipment,

6 Risk Assessment SLIDE-6 The risk assessment starts with a survey of the facility s electrical system, beginning at the electrical utility, then the electrical service, the main distribution system(s), all panel boards, all disconnect switches, motors of 50 horsepower and larger, onsite generators, capacitors and the wiring. Accurate one-line drawings of the electrical system are needed to perform the risk assessment: The maximum possible fault currents must be calculated throughout the system. Locations where arc faults are possible should be identified. Generate a hazard label in accordance with NFPA 70E and ANSI and permanently attach to electrical equipment. The risk assessment must be documented.

7 Risk Assessment SLIDE-7 The arc flash risk assessment shall be updated when a major modification or renovation takes place. It shall be reviewed periodically, not to exceed 5 years to account for changes in the electrical distribution system that could affect the results of the arc flash risk assessment. Software is available to perform calculations to determine the arc hazard and develop boundaries and specify level of PPE. Smartphone ap: ArcBlast Calculator (free) Computer software:

8 Program SLIDE-8 NFPA 70E requires the employer to implement and document an overall Electrical Safety Program (ESP) that directs activity appropriate to the risk associated with electrical hazards. Identify and minimize the hazard Training Labels Inspection Maintenance Plan every job and document first-time procedures De-energize, Protect the employee from shock, burn, blast (PPE) Insulated tools Voltage testers Audit

9 Procedure SLIDE-9 The ESP shall identify the procedures to be utilized before work is started by employees exposed to an electrical hazard. The ESP shall include a risk assessment procedure that addresses employee exposure to electrical hazards. The procedure shall identify the process to be used by the employee before work is started to carry out the following: Identify hazards Assess risks Implement risk control according to a hierarchy of methods

10 Procedure SLIDE-10 ESP procedures can include, but are not limited to, the following: Purpose of task Qualifications and number of employees to be involved Hazardous nature and extent of task Limits of approach Safe work practices to be used PPE involved Insulating materials and tools involved Special precautionary techniques Electrical diagrams Equipment details Sketches/pictures of unique features Reference data

11 Training SLIDE-11 NFPA 70E requires safety training for employees who face a risk of electrical hazard that is not reduced to a safe level by the electrical installation. Said employees shall be trained: To understand the specific hazards associated with electrical energy. In safety-related work practices which provide protection from the electrical hazards. To identify and understand the relationship between electrical hazards and possible injury. The degree of training provided shall be determined by the risk to the employee. The training shall be classroom or on-the-job type, or a combination of the two.

12 Training SLIDE-12 Employees exposed to shock hazards shall be trained in methods of safe release of victims from contact with exposed energized electrical conductors. Employees responsible for responding to medical emergencies shall be trained in first aid, CPR and emergency procedures. Refresher training shall occur annually. The electrical safety program shall be designed to provide an awareness of the potential electrical hazards to employees who work in an environment with the presence of electrical hazards.

13 Training SLIDE-13 Employees responsible for responding to medical emergencies shall be trained in the use of an Automated External Defibrillator (AED) if an employer s emergency response plan includes the use of this device. Refresher training shall occur annually. Employees are to be trained on how to remove the source of electricity and notify 911. Employers shall verify at least annually that employee training is current.

14 Training SLIDE-14 A qualified person shall be trained and knowledgeable of the construction and operation of equipment or a specific work method and be trained to recognize and avoid the electrical hazards that might be present with respect to that equipment or work method. Such persons shall also be familiar with the proper use of the special precautionary techniques, applicable electrical policies and procedures, PPE, insulating and shielding materials, and insulated tools and test equipment.

15 Training SLIDE-15 Qualified persons permitted to work within the limited approach boundary of exposed energized electrical conductors operating at 50 volts or more shall, at a minimum, be trained in all of the following: Skills and techniques necessary to distinguish exposed energized electrical conductors from other parts of electrical equipment Skills and techniques necessary to determine the nominal voltage of exposed energized electrical conductors Approach distances specified in NFPA 70E and the corresponding voltages to which the qualified person will be exposed

16 Training SLIDE-16 Qualified person training shall include training on decisionmaking process necessary to be able to do the following: Perform the job safety planning Identify electrical hazards Assess the associated risk Select the appropriate risk control methods from the hierarchy of controls, including PPE

17 Training SLIDE-17 Employees shall be trained to select an appropriate test instrument and shall demonstrate how to use a device to verify the absence of voltage, including interpreting indications provided by the device. The training shall include information that enables the employee to understand all limitations of each specific test instrument that might be used. Tasks that are performed less often than once per year shall require retraining before the performance of the work practices involved.

18 Training SLIDE-18 The employer shall determine, through regular supervision or through inspections conducted on at least an annual basis, that each employee is complying with the safety-related work practices required by this standard. Retraining shall be performed at intervals not to exceed 3 years. The employer shall document that each employee has received the training. This documentation shall be made when the employee demonstrates proficiency in the work practices involved and shall be maintained for the duration of the employee s employment. The documentation shall contain the content of the training, each employee s name, and dates of training.

19 Training SLIDE-19 Retraining in safety-related work practices and applicable changes in this standard shall be performed at intervals not to exceed three years. An employee shall receive additional training (or retraining) if any of the following conditions exists: The supervision or annual inspections indicate that the employee is not complying with the safety-related work practices. New technology, new types of equipment, or changes in procedures necessitate the use of safety-related work practices that are different from those that the employee would normally use. The employee must employ safety-related work practices that are not normally used during his or her regular job duties.

20 Qualified Person SLIDE-20 This standard defines a qualified person as one who has skills and knowledge related to the construction and operation of the electrical equipment and installations and has received safety training to recognize and avoid the hazards involved. Unqualified persons shall not be permitted to approach nearer than the limited approach boundary of energized conductors. Where there is a need for an unqualified person to cross the limited approach boundary, a qualified person shall advise them of the possible hazards and continuously escort the unqualified person while inside the limited approach boundary. Under no circumstance shall the escorted unqualified person be permitted to cross the restricted approach boundary.

21 Qualified Person SLIDE-21 Only qualified persons following the requirements for working inside the restricted approach boundary shall be permitted to defeat or bypass an electrical safety interlock over which the person has sole control, and then only temporarily while the qualified person is working on the equipment. Employees who perform maintenance on electrical equipment and installations shall be qualified persons.

22 Shock & Arc Boundaries SLIDE-22

23 Shock Boundary SLIDE-23 Limited Approach Boundary: An approach limit at a distance from an exposed energized electrical conductor within which a shock hazard exists. Restricted Approach Boundary: An approach limit at a distance from an exposed energized electrical conductor within which there is an increased risk of shock, due to electrical arc-over combined with inadvertent movement, for personnel working in close proximity to the energized electrical conductor. NOTE: Prohibited approach boundary has been DELETED from 2015 NFPA 70E. Shock boundaries apply only if employees are exposed to energized electrical conductors.

24 Shock Boundary SLIDE-24 Unqualified persons shall not be permitted to approach nearer than the limited approach boundary of energized conductors. Where unqualified persons are working at or close to the limited approach boundary, the designated person in charge of the work space where the electrical hazard exists shall advise the unqualified persons of the electrical hazard and warn them to stay outside of the limited approach boundary. The shock protection boundaries and the arc flash boundary are independent of each other. In certain instances, the arc flash boundary might be a greater distance from the energized electrical conductor than the limited approach boundary.

25 Shock Boundary SLIDE-25 Qualified persons shall not approach or take any conductive object closer to exposed energized electrical conductors operating at 50 volts or more, than the restricted approach boundary set forth in NFPA 70E, unless : The qualified person is insulated or guarded from the energized electrical conductors or The energized electrical conductors are insulated from the qualified person and from any other conductive object at a different potential. To cross the restricted approach boundary and enter the restricted space, qualified persons must do the following: Have a plan that is documented and approved by management Use PPE that is appropriate for working near exposed energized conductors and is rated for the voltage and energy level involved

26 Shock Boundary SLIDE-26 Where there is a need for an unqualified person(s) to cross the limited approach boundary, a qualified person shall advise them of the possible hazards and continuously escort the unqualified persons while inside the limited approach boundary. Under no circumstance shall escorted unqualified persons be permitted to cross the restricted approach boundary. The following tables are used to determine the limited and restricted approach boundaries for AC and DC currents:

27 Boundary SLIDE-27

28 Arc Flash Boundary SLIDE-28 The arc flash boundary shall be the distance at which the incident energy equals 1.2 calories per centimeter squared (second degree burn). The following table shall be used to determine the arc flash boundary:

29 Arc Flash Boundary SLIDE-29

30 Arc Flash Boundary SLIDE-30

31 PPE SLIDE-31 Where it has been determined that work will be performed within the arc flash boundary, PPE shall be selected based on the incident energy exposure of the worker by either: Calculating the incident energy or Using NFPA 70E PPE table 2015 NFPA 70E has deleted PPE HRC 0 because the PPE table should only show requirements where arc-rated clothing was required. HRC 0 would mean the worker was outside the arc flash boundary and did not need arc-rated PPE. ALL AR clothing is Flame Resistant (FR), but not all FR clothing are Arc Rated.

32 PPE SLIDE-32 Clothing consisting of fabrics, zipper tapes, and findings made from flammable synthetic materials that melt at temperatures below 600 F shall not be used. Example: Acetate, Acrylic, Nylon, Polyester, Polyethylene, Polypropylene, and Spandex, Either alone or in blends.

33 Face Protection Face shields shall have an arc rating suitable for the arc flash exposure. Face shields with a wraparound guarding to protect the face, chin, forehead, ears, and neck area shall be used. Face shields without an arc rating shall not be used. Eye protection (safety glasses or goggles) shall always be worn under face shields or hoods. Most arc rated faceshields are tinted and can reduce visual acuity and color perception. Additional illumination of the task area might be necessary when these types of arc protective face shields are used. SLIDE-33

34 Head Protection SLIDE-34 An arc-rated balaclava shall be used with an arc-rated faceshield when the back of the head is within the arc flash boundary. An arc-rated hood shall be permitted to be used instead of an arc-rated faceshield and balaclava. An arc-rated hood shall be used when the anticipated incident energy exposure exceeds 12 cal/cm2.

35 Hand Protection SLIDE-35 Hand and arm protection shall be worn where there is possible exposure to arc flash burn. Employees shall wear rubber insulating gloves with leather protectors and rubber insulating sleeves where there is a danger of hand and or arm injury from electric shock due to contact with energized electrical conductors. Rubber insulating gloves shall be rated for the voltage for which the gloves will be exposed.

36 Hand Protection SLIDE-36 Gloves are assigned class and color code based on rating.

37 Glove Inspection SLIDE-37 Insulating electrical gloves shall be inspected daily. Daily inspection includes a visual inspection and an air test prior to use.

38 Electrical protective equipment shall be subjected to periodic electrical tests. PPE SLIDE-38

39 PPE SLIDE-39 Where it has been determined that work will be performed within the arc flash boundary, PPE shall be selected based on the incident energy exposure of the worker (in calories per square centimeter). The incident energy exposure level shall be based on the distance of the employee s face and chest from the arc source for the specific task to be performed. The following NFPA 70E tables list tasks that require PPE and which do not.

40 PPE Required SLIDE-40

41 PPE SLIDE-41

42 PPE SLIDE-42

43 PPE SLIDE-43

44 PPE Category 1 SLIDE-44

45 PPE Category 2 SLIDE-45

46 PPE Category 3 SLIDE-46

47 PPE Category 4 SLIDE-47

48 Analysis Required SLIDE-48 An incident energy analysis shall be required for the following (tables cannot be used): Tasks not listed in NFPA 70E Power systems with greater than the estimated maximum available short-circuit current Power systems with longer than the maximum fault clearing times Tasks with less than the minimum working distance

49 Job Briefing SLIDE-49 Before starting each job, the employee in charge shall conduct a job briefing with the employees involved. The briefing shall cover: Hazards associated with the job, Work procedures involved, Special precautions, Information on the energized electrical work permit, if required. Energy source controls, PPE requirements.

50 Job Briefing SLIDE-50

51 Job Briefing SLIDE-51

52 Only qualified persons shall perform tasks such as testing, troubleshooting, and voltage measuring within the limited approach boundary of energized electrical conductors operating at 50 volts or more or where an electrical hazard exists. Test instruments, equipment, and their accessories shall be rated for circuits and equipment to which they will be connected. Testing SLIDE-52

53 Testing Example on how not to do testing SLIDE-53

54 Testing Example on correct way of testing SLIDE-54

55 Energized Work SLIDE-55 Energized work shall be permitted where the employer can demonstrate that: De-energizing introduces additional hazards or increased risk or Examples of additional hazards or increased risk include, but are not limited to, interruption of life-support equipment, deactivation of emergency alarm systems, and shutdown of hazardous location ventilation equipment. The task to be performed is infeasible in a de-energized state due to equipment design or operational limitations. Only qualified persons shall work on electrical conductors that have not been put into an electrically safe work condition. When working within the limited approach boundary or the arc flash boundary of exposed energized electrical conductors that are not placed in an electrically safe work condition, work to be performed shall be considered energized electrical work and shall be performed by written permit only.

56 Permit SLIDE-56 A permit shall not be required if a qualified person is provided with and uses appropriate safe work practices and PPE under any of the following conditions: Thermography and visual inspections if the restricted approach boundary is not crossed Access to and egress from an area with energized electrical equipment if no electrical work is performed and the restricted approach boundary is not crossed General housekeeping and miscellaneous non-electrical tasks if the restricted approach boundary is not crossed Testing, troubleshooting, and voltage measuring

57 Permit SLIDE-57

58 Permit SLIDE-58

59 Permit SLIDE-59

60 Insulated Tools SLIDE-60 Employees shall use insulated tools when working inside the limited approach boundary of exposed energized electrical conductors where tools might make accidental contact. Insulated tools shall be rated for the voltages on which they are used. Insulated tools and equipment shall be inspected prior to each use.

61 Maintenance SLIDE-61 An Electrical Preventive Maintenance (EPM) program should be conducted on a routine basis to ensure safe operation. An EPM not only helps the equipment work better, but it also identifies potential hazards before they cause an accident. As part of an EPM, electrical equipment should be thoroughly cleaned and routine inspections should be conducted by qualified personnel who understand how to identify loose connections, overheated terminals, discoloration of nearby insulation, and pitted contacts. Using corrosion resistant terminals and insulate exposed metal parts if possible Sealing all open areas of equipment to ensure rodents and birds cannot enter Verifying that all relays and breakers are set and operate properly

62 Label Electrical equipment such as switchboards, panelboards, industrial control panels, meter socket enclosures, and motor control centers, that are likely to REQUIRE examination, adjustment, servicing, or maintenance while energized, shall be field marked with a label containing the following information: Nominal system voltage Arc flash boundary And at least one of the following: Available incident energy and the corresponding working distance or arc flash PPE category but not both Minimum arc rating of clothing Site specific PPE SLIDE-62

63 Label SLIDE-63 The method of calculating and data to support the information for the label shall be documented. Labels applied prior to September 30, 2011, are acceptable if they contain the available incident energy or required level of PPE. Where the review of the arc flash hazard risk assessment identifies a change that renders the label inaccurate, the label shall be updated (NEW). The owner of the electrical equipment shall be responsible for the documentation, installation, and maintenance of the fieldmarked label (NEW).

64 Overhead Line When unqualified persons are working on the ground or in an elevated position near overhead lines, the location shall be such that the employee and the longest conductive object the employee might contact do not come closer to any unguarded, energized overhead power line than the limited approach boundary in Table 130.4(C). Objects that are not insulated for the voltage involved should be considered to be conductive. SLIDE-64

65 Contractors SLIDE-65 Where the host employer has knowledge of hazards covered by NFPA 70E that are related to the contract employer s work, there shall be a documented meeting between the host employer and the contract employer. The host employer shall inform contract employers of the following: Known hazards that are covered by this standard, that are related to the contract employer s work, and that might not be recognized by the contract employer or its employees Information about the employer s installation that the contract employer needs to make a hazard assessment on The host employer shall report observed contract employer related violations of this standard to the contract employer.

66 LOTO SLIDE-66 The employer shall: Establish LOTO procedures for the organization, Provide training to employees, Provide equipment necessary to execute the details of the procedure, Audit execution of the procedures to ensure employee understanding/ compliance, and Audit the procedure for improvement opportunity and completeness. The audit shall be conducted at least annually by a qualified person and shall cover at least one LOTO in progress and the procedure details. LOTO retraining shall be provided: When LOTO procedures change and At least once every 3 years.

67 Audit SLIDE-67 The ESP shall be audited to verify the principles and procedures of the ESP are in compliance with the latest NFPA 70E. The frequency of the ESP audit shall not exceed 3 years. Field work shall be audited to verify the requirements contained in the procedures of the ESP are being followed. When the auditing determines that the procedures of the ESP are not being followed, the appropriate revisions to the training program or revisions to the procedures shall be made. The audit shall be documented. The frequency of the field audit shall not exceed 1 year.

68 Special Equipment SLIDE-68 NFPA 70E has additional sections on special equipment: ARTICLE 310 Safety-Related Work Practices for Electrolytic Cells ARTICLE 320 Safety Requirements Related to Batteries and Battery Rooms ARTICLE 330 Safety-Related Work Practices for Use of Lasers ARTICLE 340 Safety-Related Work Practices: Power Electronic Equipment ARTICLE 350 Safety-Related Work Requirements: Research and Development Laboratories Informative Annex L Typical Application of Safeguards in the Cell Line Working Zone

69 OSHA Although OSHA has not adopted the NFPA 70E standard it has issued citations federally under the general duty clause (5a) and in California using the Injury and Illness Prevention Program (IIPP) GISO 3203 regulation. Training Inspection Personal Protective Equipment Recordkeeping SLIDE-69

70 OSHA SLIDE-70 Fed-OSHA s new standard on the construction of electric power transmission and distribution lines and equipment which went into effect July 10, This standard requires employers to: Make reasonable estimates of incident energy starting January 1, Ensure that each employee exposed to hazards from electric arcs wears the required arc-rated protective equipment when the estimated incident energy exceeds 2 calories per centimeter squared (cal/cm 2) starting April 1, 2015.

71 OSHA SLIDE-71 Revised minimum approach distances become effective on April 1, Information to help employers establish minimum approach distances appears in appendices to the standards. The degree of training must be determined by risk to the worker for the hazard involved. Qualified workers must have training to recognize and control or avoid electrical hazards present at the worksite. Line-clearance tree trimmers must have training to distinguish exposed live parts and to determine the voltage on those parts, and they must have training in minimum approach distances and how to maintain them. Host and contract employers must share information with each other on safety-related matters and must coordinate their work rules and procedures.

72 Cal/OSHA SLIDE-72 High voltage electrical safety orders section states that employees shall not be permitted to approach or take any conductive object without an approved insulating handle closer to exposed energized parts than shown in Table through Table unless: The employee is insulated or guarded from the energized part (gloves rated for the voltage involved shall be considered insulation of the employee from the energized part), or The energized part is insulated or guarded from the employee and any other conductive object at a different potential.

73 Cal/OSHA SLIDE-73

74 Cal/OSHA SLIDE-74 ESO requires that insulating equipment designed for the voltage levels to be encountered shall be provided and the employer shall ensure that they are used by employees. The employer is responsible for the periodic visual and electrical re-testing of all insulating gloves, sleeves and blankets. The employer shall ensure that each employee who is exposed to the hazards of flames or electric arcs does not wear clothing that, when exposed to flames or electric arcs, could increase the extent of injury that would be sustained by the employee. This subsection prohibits clothing made from the following types of fabrics, either alone or in blends, unless the employee can demonstrate that the fabric has been treated with flame retardant: acetate, nylon, polyester, and rayon.

75 Cal/OSHA SLIDE-75 Gloves, sleeves, and blankets that have been electrically tested but not issued for service shall not be placed into service unless they have been electrically tested within the previous twelve months. Gloves, sleeves and blankets shall be marked to indicate compliance with the re-test schedule and shall be marked with either the date tested, or the date the next test is due. When not being used, insulating gloves and sleeves shall be stored in glove bags or suitable containers. Insulating blankets shall be stored in a canister or other means that offers equivalent protection. Insulating equipment shall be stored away from direct sunlight, steampipes, radiators and other sources of excessive heat and shall be protected from physical damage.

76 Cal/OSHA SLIDE-76 Gloves, sleeves and blankets shall not be folded while in storage; however, blankets shall be permitted to be rolled for storage. Insulating equipment shall be visually inspected for defects and damage, and shall be cleaned prior to use each day. Rubber gloves shall be air and water tested at the beginning of each work period and at any other time when the glove's condition is in doubt. The gloves shall be visually examined over their entire inner and outer surface for any defects, i.e., burns, cuts, cracks, punctures and weak spots; and Have the cuff stretched to detect abrasions and weak spots.

77 Cal/OSHA SLIDE-77 ESO When employees are performing work on or associated with exposed lines or equipment energized at 50 volts or more, persons trained in first aid including CPR shall be available as follows: For field work involving two or more employees at a work location, at least two trained persons shall be available. Exception: Only one trained person need be available if all new employees are trained in first aid, including CPR, within 3 months of their hiring dates. For fixed work locations such as generating stations, the number of trained persons available shall be sufficient to ensure that each employee exposed to electric shock can be reached within 4 minutes by a trained person. Exception: Where the existing number of employees is insufficient to meet this requirement (at a remote substation, for example), all employees at the work location shall be trained.