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 Post subject: IEEE 1584
PostPosted: Fri Dec 21, 2012 2:41 pm 
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I'am updating my 70E lecture and found in my notes this quote "Qualifying Electrical Equipment for arc flash analysis and labeling in accordance with IEEE 1584 is equipment with 208 volts or greater and fed by a transformer with 75 kVA and greater. I couldn't find this anywhere in the 2012 70E Handbook. Has it been deleted or have I miss quoted the IEEE 1584? I hope someone can help me
I have found the Section 130.5(A) and Informational Note: For information on estimating the arc flash boundary, see Annex D
I also found Section 130.5 Informational Note No. 5: See IEEE 1584 for more information regarding arc flash hazards for three-phase systems rated less than 240 volts


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PostPosted: Fri Dec 21, 2012 5:53 pm 
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Laura Vergeront wrote:
I'am updating my 70E lecture and found in my notes this quote "Qualifying Electrical Equipment for arc flash analysis and labeling in accordance with IEEE 1584 is equipment with 208 volts or greater and fed by a transformer with 75 kVA and greater. I couldn't find this anywhere in the 2012 70E Handbook. Has it been deleted or have I miss quoted the IEEE 1584? I hope someone can help me
I have found the Section 130.5(A) and Informational Note: For information on estimating the arc flash boundary, see Annex D
I also found Section 130.5 Informational Note No. 5: See IEEE 1584 for more information regarding arc flash hazards for three-phase systems rated less than 240 volts

Yes it was deleted from NFPA 70E. It originated in IEEE 1584 4.2 Step 1. The exact text is as follows:

"Equipment below 240 V need not be considered unless it involves at least one 125 kVA or larger lowimpedance
transformer in its immediate power supply."

We have been reviewing this exception for the next edition. The transformer size / short circuit current will ultimately be lowered but there is an ongoing debate as to how low to go. Some where around 30 to 45 kVA and short circuit currents between 2500 to 5000 Amps seem to be the front runners. I headed up a task group on this a while back and also suggested we add a default incident energy of perhaps 4 cal/cm2 if calculations are not performed under this exception. The idea would be to "force" people using the exception to wear some form of arc rated protection. There are other threads throughout this form where I have discussed even more detail. Thanks for the question and I hope this helps!

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PostPosted: Sat Dec 22, 2012 11:49 am 
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brainfiller wrote:
Yes it was deleted from NFPA 70E. It originated in IEEE 1584 4.2 Step 1. The exact text is as follows:

"Equipment below 240 V need not be considered unless it involves at least one 125 kVA or larger lowimpedance
transformer in its immediate power supply."

We have been reviewing this exception for the next edition. The transformer size / short circuit current will ultimately be lowered but there is an ongoing debate as to how low to go. Some where around 30 to 45 kVA and short circuit currents between 2500 to 5000 Amps seem to be the front runners. I headed up a task group on this a while back and also suggested we add a default incident energy of perhaps 4 cal/cm2 if calculations are not performed under this exception. The idea would be to "force" people using the exception to wear some form of arc rated protection. There are other threads throughout this form where I have discussed even more detail. Thanks for the question and I hope this helps!


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PostPosted: Sat Dec 22, 2012 11:51 am 
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brainfiller wrote:
Yes it was deleted from NFPA 70E. It originated in IEEE 1584 4.2 Step 1. The exact text is as follows:

"Equipment below 240 V need not be considered unless it involves at least one 125 kVA or larger lowimpedance
transformer in its immediate power supply."

We have been reviewing this exception for the next edition. The transformer size / short circuit current will ultimately be lowered but there is an ongoing debate as to how low to go. Some where around 30 to 45 kVA and short circuit currents between 2500 to 5000 Amps seem to be the front runners. I headed up a task group on this a while back and also suggested we add a default incident energy of perhaps 4 cal/cm2 if calculations are not performed under this exception. The idea would be to "force" people using the exception to wear some form of arc rated protection. There are other threads throughout this form where I have discussed even more detail. Thanks for the question and I hope this helps!

Thank you for the information
I like to stay current on safety when I give my lectures. I want to keep my fellow electricians as safe as possible when working around energized electrical work.


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PostPosted: Sat Dec 22, 2012 11:52 am 
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So from what I understand its other than dwelling units that need arc flash hazard analysis?


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