Arc Flash Studies

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Davebones

Senior Member
We are going to go ahead and get the Arc Flash Study done on our electrical system . One of the companys looking at this says that we should do this for all panels regardless of the voltage . ( 208V , 240V and 480V ) They are saying that down the road this will become required anyway . Is this true for the lower voltage panels ???
 

raider1

Senior Member
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Location
Logan, Utah
Yes, there is an arc flash hazard at the lower voltage level panels such as 208 and 240 volt single and 3 phase systems.

Chris
 

raider1

Senior Member
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Location
Logan, Utah
NFPA 70E 2012 edition already requires an Arc flash hazard analysis for any equipment that poses an arc flash hazard. A 208 or 240 volt panelboard would pose an arc flash hazard and therefore an analysis would be required.

Chris
 

charlie b

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Location
Seattle, WA
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Electrical Engineer
I thought panels that were served by a 240/120 1P transformer 112.5kVA were exempt.
I thought it was 125 KVA or under. But it is not so much that they are exempt, as they still need an arc flash hazard label. But you don't need to do an analysis, in order to conclude that the hazard level is level 0.
 

charlie b

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Seattle, WA
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Electrical Engineer
That is not what Jumper and I said. We both believe that if the panel is fed from a small enough transformer (we named different sizes), then (1) There is still an arc flash hazard, and you still need the label on the panel, but (2) You don't need to do a calculation, and can call it a hazard level 0 without any further considerations.
 

zog

Senior Member
Location
Charlotte, NC
I thought it was 125 KVA or under. But it is not so much that they are exempt, as they still need an arc flash hazard label. But you don't need to do an analysis, in order to conclude that the hazard level is level 0.
It was <125kvA and that note has been removed
 

jim dungar

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Location
Wisconsin
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Retired Electrical Engineer - Power Systems
It was <125kvA and that note has been removed
It was removed form NFPA70E. You are now referred to IEE1584 for the answer to this question, where excluding 125kVA <240V is still an accepted practice.
 
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