ARC Flash Labels for DAS Enclosure

V

Varshini Guduru

Member
Location
New Jersey
Occupation
Project Engineer
Hi All,

I have a question for the ARC Flash Study labels . I am a Project Engineer for a 10MW DC job which employs a DAS Monitoring system. The proposed system includes several Weather sensors and DAS Enclosure which requires 120V Input .

That said , per the NEC code 110.16 - "Electrical equipment, such as switchboards, switchgear, panelboards, industrial control panels, meter socket enclosures, and motor control centers, that is in other than dwelling units, and is likely to require examination, adjustment, servicing, or maintenance while energized, shall be field or factory marked to warn qualified persons of potential electric "arc flash hazards.

My understanding is this Enclosure would typically need an ARC Flash label . But , I do have a contractor who resists this installation as they think it is not needed given the voltage of 120V which is very less .

Any assistance of yours is very helpful. Thank you !
 
There is no industry wide accepted method for calculating Arc Flash Incident Energy for single phase circuits. But you still have the possibility of electric shock

I would prefer to see a "No Arc Flash Hazard" label versus nothing, then I know it was evaluated.
 
I would consider using a general 'Warning: Arc Flash and Shock Hazard' label or a computer-aided program to calculate the single-phase arc flash for the device
 
Circuit voltage is irrelevant to the rule's language. I agree with the OP.

My 2017 NEC handbook shows a generic label as an example that satisfies the code. No calcs necessary.
 
Since the 2017 NEC the 110.16(A) requirement is for a general AF warning label. It does not require an incident energy calculation. This is an evolving area in the NEC where 110.16(B) is changing with each new revision to require more detailed AF labels in more areas.
 
You can still get a nasty burn from an AF in a 120/240V single phase panel. The incident energy can be calculated but there is less agreement on how than with higher voltage circuits. Same with DC, it's not as thoroughly studied as AC so there are multiple ways to calculate the incident energy and there is not the same wide agreement on how best to do it as with AC.
 
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