create a Job Hazard Analysis for a electrical contractor doing a start up of a new electrical switchboard in a JHA format

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# Arc Flash (cont.) ## What are the hazards related to arc flash? (cont.) An arc flash may be caused by many factors or events, such as: - Unintentional tool contact with live parts - A tool dropped on the ground, which creates a spark which starts an arc discharge - Equipment failure due to poor maintenance or improper design - Use of tools that spark - Corrosion of contact surfaces - Loose contacts - Worn or damaged insulation - Dust and condensation on the insulating materials (The dust or moisture provide a path for the electrical current and can lead to flashovers that create an arc discharge) - Incorrect installation of conductors, such as when conductors of different phases are installed too close - Incorrect installation of arc-resistant equipment - Incorrect work procedures. The possibility of an arc flash increases when there are exposed energized electrical conductors or circuit parts; or when safe work procedures are not followed. ## What elements should be considered when doing an arc flash risk assessment? An arc flash risk assessment should be done to: - identify arc flash hazards - determine the likelihood of an arc flash, and the injuries it may cause - determine the severity of the injuries - determine what protective measures are needed, including personal protective equipment (PPE) When estimating the likelihood and severity of the event, consider factors such as the design of the electrical equipment, the presence of an overcurrent protective device, and operating time. Also important is the condition of the electrical equipment, and the effectiveness of any maintenance activities. What are some protective measures that can be taken? Arc Flash CCOHS

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# Arc Flash (cont.) ## What elements should be considered when doing an arc flash risk assessment? (cont.) Whenever possible, do not work on energized equipment. Always follow lockout/tagout procedures as part of a hazardous energy control program. Other protective measures include: - Making sure conductors and circuit parts are in a safe working condition - Using lower energy equipment or current energy limiting devices - Guarding energized electrical conductors and circuit parts - Using arc flash approach boundaries, including barricades - Increasing the working distance - Using non-contact instruments or procedures, where possible - Using non-sparking tools - Implementing work permits, safe work procedures, and job planning - Posting signs alerting of the hazards - Wearing shock and arc flash personal protective equipment (PPE) ## What would be included in preventive maintenance? Preventive maintenance includes: - Regular inspection for wear and tear of insulation, corrosion, poor connections, overheated electrical conductors, excessive pitting of contacts, or excessive moisture, water, or ice on the equipment. - Regular measurements of critical components. - Routine inspections of circuit breakers and relays (develop a testing schedule based on the manufacturer's instructions or the InterNational Electrical Testing Association (NETA) guidelines). - Follow established maintenance requirements, including a parts replacement schedule. - Keep electrical drawings current. ## What are approach boundaries? Boundaries are used to limit how close workers and others should be to the equipment or circuits, especially when work is being done. Arc Flash CCOHS

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# Arc Flash (cont.) ## What are approach boundaries? (cont.) An arc flash boundary is the term used to describe the distance at which a person without personal protective equipment (PPE) may get a second-degree burn if an arc flash occurs. It is assumed that a second-degree burn occurs when the incident energy received by the skin equals 5 J/cm2 (1.2 cal/cm2). A second-degree burn is usually treatable. There are two types of boundaries that are used: - Limited approach boundary - the distance from an exposed energized electrical conductor or circuit part a person may approach when a shock hazard exits (i.e., if the person is wearing appropriate PPE and are supervised by a qualified person). - Restricted approach boundary - the distance from an exposed energized electrical conductor or circuit part a qualified person (only) may approach when there is an increased likelihood of electric shock due to electrical arc over combined with inadvertent movement. Flash boundary Limited approach boundary Restricted approach boundary Any exposed and energized conductor or circuit part The distance of the boundaries will vary, and depend on: - the system present (alternating-current or direct-current systems) - the voltage range (phase to phase) or the nominal potential difference - the presence of equipment including fuses, relays, circuit breakers, exposed movable conductors or fixed circuit parts - the use of devices to restrict inadvertent movement Arc Flash CCOHS

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# Arc Flash (cont.) ## What are approach boundaries? (cont.) Important to arc flash boundaries is the role of qualified persons. A qualified person is someone who has been trained in and has knowledge about the construction and operation of the equipment or work methods. They must be familiar with appropriate techniques, policies and procedures, work permits, PPE, insulating and shielding materials, insulated tools, test equipment, etc. For example, unqualified workers should remain a distance away from the exposed energized conductors or circuit parts (including any equipment or objects they may handle). They should not cross into the arc flash boundary unless they are wearing appropriate PPE and are supervised by a qualified person. At no time should an unqualified person enter the restricted approach boundary. Qualified person may enter the restricted space provided any necessary work permits, PPE, tools, equipment, and measures necessary to reduce the likelihood of contact are taken. ## How is arc flash personal protective equipment (PPE) chosen? Workers must know how to select, use, and care for the necessary PPE, and understand the limitations of the PPE. The CSA standard Z462:21 "Workplace Electrical Safety" provides two methods that can be used to determine what type of PPE is required for a specific job: 1. The incident energy analysis 2. The arc flash PPE category While either method can be used, only one method should be used at a time when working on the same piece of equipment (not both). The first method, incident energy analysis, is based on the distance between the worker's face and chest to the source. It uses the value of the estimated energy of the flash to determine the level of protection that must be provided by the PPE. The second method, arc flash PPE category method, uses the arc flash risk assessment of the tasks and equipment condition to determine if arc flash-rated PPE is required. Once determined that arc flash PPE is require…

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# Table 1 provides task-based examples of exposure assessments. (cont.) ## Notes: (cont.) <table><tr><th rowspan="2">Voltage range (kV) **</th><th rowspan="2">Fault current (kA)</th><th colspan="4">Maximum clearing time (cycles)</th></tr><tr><td>4 cal/cm²</td><td>5 cal/cm²</td><td>8 cal/cm²</td><td>12 cal/cm²</td></tr><tr><td rowspan="4">36.1 to 46.0</td><td>5</td><td>129</td><td>161</td><td>257</td><td>386</td></tr><tr><td>10</td><td>51</td><td>64</td><td>102</td><td>154</td></tr><tr><td>15</td><td>29</td><td>36</td><td>58</td><td>87</td></tr><tr><td>20</td><td>19</td><td>24</td><td>38</td><td>57</td></tr><tr><td rowspan="4">46.1 to 72.5</td><td>20</td><td>18</td><td>23</td><td>36</td><td>55</td></tr><tr><td>30</td><td>10</td><td>13</td><td>20</td><td>30</td></tr><tr><td>40</td><td>6</td><td>8</td><td>13</td><td>19</td></tr><tr><td>50</td><td>4</td><td>6</td><td>9</td><td>13</td></tr><tr><td rowspan="4">72.6 to 121.0</td><td>20</td><td>10</td><td>12</td><td>20</td><td>30</td></tr><tr><td>30</td><td>6</td><td>7</td><td>11</td><td>17</td></tr><tr><td>40</td><td>4</td><td>5</td><td>7</td><td>11</td></tr><tr><td>50</td><td>3</td><td>3</td><td>5</td><td>8</td></tr><tr><td rowspan="4">121.1 to 145.0</td><td>20</td><td>12</td><td>15</td><td>24</td><td>35</td></tr><tr><td>30</td><td>7</td><td>9</td><td>15</td><td>22</td></tr><tr><td>40</td><td>5</td><td>6</td><td>10</td><td>15</td></tr><tr><td>50</td><td>4</td><td>5</td><td>8</td><td>11</td></tr><tr><td rowspan="4">145.1 to 169.0</td><td>20</td><td>12</td><td>15</td><td>24</td><td>36</td></tr><tr><td>30</td><td>7</td><td>9</td><td>15</td><td>22</td></tr><tr><td>40</td><td>5</td><td>7</td><td>10</td><td>16</td></tr><tr><td>50</td><td>4</td><td>5</td><td>8</td><td>12</td></tr><tr><td rowspan="4">169.1 to 242.0</td><td>20</td><td>13</td><td>17</td><td>27</td><td>40</td></tr><tr><td>30</td><td>8</td><td>10</td><td>17</td><td>25</td></tr><tr><td>40</td><td>6</td><td>7</td><td>12</td><td>17</td></tr><tr><td>50</td><td>4</td><t…

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# What are the benefits of doing a job safety analysis? (cont.) ## Who should conduct a job safety analysis? (cont.) The basic steps in conducting a job safety analysis are: - Select the job to be analyzed - Break the job down into a sequence of steps - Identify potential hazards - Determine preventive measures to control these hazards - Communicate the results ## What is important to know when "selecting the job"? Ideally, all jobs should be subjected to a job safety analysis. In some cases, practical constraints are posed by the amount of time and effort required to do a job safety analysis. Another consideration is that each job safety analysis will require revision whenever equipment, raw materials, processes, or the environment changes. For these reasons, it is usually necessary to identify which jobs are to be analyzed. Even if an analysis of all jobs is planned, this step ensures that the most critical jobs are examined first. Factors to be considered in setting a priority for the analysis of jobs include: - Incident frequency and severity: jobs where incidents occur frequently or where they occur infrequently but result in serious injuries. - Potential for severe injuries or illnesses: the consequences of an incident, hazardous condition, or exposure to harmful products are potentially severe. - Newly established jobs: due to lack of experience in these jobs, hazards may not be evident or anticipated. - Modified jobs: new hazards may be associated with changes in job procedures. - Infrequently performed jobs: workers may be at greater risk when undertaking non- routine jobs, and a JSA provides a means of reviewing hazards. ## How do I break the job into "basic steps"? After a job has been chosen for analysis, the next stage is to break the job into steps. A job step is defined as a segment of the operation necessary to advance the work. Job Safety Analysis CCOHS

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# Occupational Safety and Health Administration (cont.) ## 1910.303(h)(2) (cont.) Nonmetallic or metal-enclosed equipment located outdoors and accessible to the general public shall be designed so that exposed nuts or bolts cannot be readily removed, permitting access to live parts; - 1910.303(h)(2)(v)(D) Where nonmetallic or metal-enclosed equipment is accessible to the general public and the bottom of the enclosure is less than 2.44 m (8.0 above the floor or grade level, the enclosure door or hinged cover shall be kept locked; and - 1910.303(h)(2)(v)(E) Except for underground box covers that weigh over 45.4 kg (100 lb), doors and covers of enclosures used solely as pull boxes, splice boxes, or junction boxes shall be locked, bolted, or screwed on. - 1910.303(h)(3) Work space about equipment. Sufficient space shall be provided and maintained about electric equipment to permit ready and safe operation and maintenance of such equipment. Where energized parts are exposed, the minimum clear work space may not be less than 1.98 m (6.5 ft) high (measured vertically from the floor or platform) or less than 914 mm (3.0 ft) wide (measured parallel to the equipment). The depth shall be as required in paragraph (h)(5)(i) of this section. In all cases, the work space shall be adequate to permit at least a 90-degree opening of doors or hinged panels. - 1910.303(h)(4) Entrance and access to work space. - 1910.303(h)(4)(i) At least one entrance not less than 610 mm (24 in.) wide and 1.98 m (6.5 ft) high shall be provided to give access to the working space about electric equipment. - 1910.303(h)(4)(i)(A) On switchboard and control panels exceeding 1.83 m (6.0 ft) in width, there shall be one entrance at each end of such boards unless the location of the switchboards and control panels permits a continuous and unobstructed way of exit travel, or unless the work space required in paragraph (h)(5)(i) of this section is doubled. ## 1910.303(h)(4)(i)(B) Where one entra…