3/11/2024 0 Comments Nfpa 70e arc flash boundary table130.4(A) states the purposes of performing a shock risk assessment, while 130.4(B) provides the needed information concerning “additional protective measures” as provided in Section 110.1(H)(3). “N” indicates that a new section was added. (3) The personal and other protective equipment required by this standard to protect against the shock hazard (1) The voltage to which personnel will be exposed When the additional protective measures include the use of PPE, the following shall be determined: If additional protective measures are required, they shall be selected and implemented according to the hierarchy of risk control identified in 110.1(H). (3) To determine if additional protective measures are required, including the use of PPE (2) To estimate the likelihood of occurrence of injury or damage to health and the potential severity of injury or damage to health A shock risk assessment shall be performed: But before the tables, Section 130.4 Shock Risk Assessment states: In NFPA 70E-2018, Article 130 Section 130.4 outlines the shock protection boundaries. Now, this was an old paper, but the percentages even now tell a real story about the risk involved in dealing with lower voltages.įigure 1: Lethal Voltages at an Industrial Facility What is very surprising to most people is that 100–250 V is right next to it at 39%. It is also not surprising that 250–600 V (mostly 480 V) is the largest percentage of fatalities at 45%. Since these were industrial sites and not utilities, it’s not surprising to see that the over-600 V range is only 11% of the fatalities. DuPont included Figure 1, which was the result of a study done at their facilities. Somewhere in the 1999–2002 range, an IEEE Electrical Safety Workshop presentation by Lanny Floyd and Danny Liggett of E.I. After all, what electrician or technician hasn’t been shocked at one time or another and just received a slight jolt, maybe a sting - and you look around to make certain no one was watching? We tend to think of low-voltage shocks as more of a nuisance then a real threat, but that is wrong-headed thinking. Arc flash gets the most attention because of the serious injuries caused by an arc flash, not to mention the visual and audible results, which tend to be more impressive than a shock. Shock remains the number-one cause of electrical fatalities and has been for several years. Until that release, the current edition must be referenced. The 2021 edition will be released to the public in late September or early October, first in pdf form, then as a printed document. The 2018 edition of NFPA 70E is still active, even though many people are looking forward to a new edition in 2021.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |