Technical Articles

nfpa 70e

Evaluation of Onset to Second Degree Burn Energy in Arc Flash

Our interest in determining accurate onset to second degree burn energy and its significance in computing the arc flash boundary is focused on the prevention of injury to the skin of a human who might be exposed to an arc-flash. During the last two decades different formulas have been proposed to calculate incident energy at an assumed working distance, and the arc flash boundary in order to determine arc rated personal protective equipment for Qualified Electrical Workers. Among others, the

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Include Date on Arc Flash Label?

According to the 2015 Edition of NFPA 70E 130.5(2), The arc flash risk assessment “…shall be reviewed periodically, at intervals 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.” According to 130.5(D) Equipment Labeling, the date is not listed as a requirement for including on the label. However, many believe the date is an important aspect of the label in order to keep track

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2015 NFPA 70E Changes

The following is an article that I wrote a few years ago listing the major changes for the 2015 edition. It was originally published in the May 2014 issue of Electrical Contractor Magazine and is provided here as a resource for your use. Change Is On The Way! 2015 NFPA 70E Published: May 2014 – Electrical Contractor Magazine By Jim Phillips Deja vu? Déjà vu is that feeling you get when you think you have seen or done something before. NFPA

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Arc Flash Labels-PPE Category

In the NFPA 70E-2015 Handbook, page 122, 130.5(D) states incident energy or PPE category shall be on the equipment arc flash label, but not both. Yet when reviewing Annex H in the NFPA 70E-2015 handbook, on page 279 it states “Arcflash PPE categories may be applicable when using incident energy method to perform an arc flash risk assessment. When performing an incident energy analysis, the arc flash labels created may include an arc flash category”. Am I missing something or

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Work on an energized disconnect

Recently, a client asked if there was something I could point to in the NFPA 70E Standard that specifically prevented a qualified electrician from working on a disconnect after it was shut off, but with the line side left energized? I asked exactly what he meant? He said our electricians sometimes need to disconnect one of our 480 volt welders for repair or to be serviced. We sometimes have more than one welder on a circuit, so shutting off the

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Lock Out / Tag Out Simple vs. Complex

OSHA and NFPA 70E refer to a Simple LOTO as involving only one person/conductors/circuit part(s). A Complex LOTO is when there are conditions such as more than one person/circuit/shift/source involved – A complex LOTO has significantly more requirements. Here is this week’s question: Have you ever performed a complex LOTO? Yes No ANSWER   About Jim Phillips: Electrical Power and Arc Flash Training Programs – For over 30 years, Jim Phillips has been helping tens of thousands of people around the world,

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AF Boundary Marking

Hi, As per NFPA 70E, we have 3 boundaries to mark(AFB, limited and restricted). It is easy to mark and follow only one boundary which is greater than two. Sometimes AFB is more than limited approach boundary, so we marked the AFB and follow that. But sometimes AFB is very less for lighting boards and power distribution boards. Also it is not feasible to mark limited boundary as it is very big for small board placed in normal working area

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Arc flash detection relay

What is the practice for the use of arc detection relay trip time in the arc incident energy calculations? NFPA-70E recognized arc detection relay but kept under “Other Methods” as opposed to “Incident Energy Reduction Method”. Does this means the arc flash relay tripping time should not be used for the arc incident energy calculations? READ MORE.

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NFPA 70E

AS I understand it in NFPA 70 E 130.7 table any Panel 240 volts and below require Category 1 PPE. Also NFPA says any voltage 120 volts Phase to Phase is not required. If so shouldn’t Residential Electricians also comply? REPLY

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NFPA 70E and Improved Electrical Maintenance

The duration of an arc flash can be greatly affected by the condition of electrical protective devices – i.e. circuit breakers, relays etc. NFPA 70E has been placing an increased emphasis on equipment being properly maintained. Has your company/client increased the emphasis on electrical maintenance as a result of 70E? Yes No Many clients – it depends CLICK to answer.

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