do electrical receptacles require an arc flash label

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mayanees said:
When I/we bring a building into compliance with 70E for arc flash labeling, all SE gear, panelboards, xfmrs, MCCs, and disconnects will be labeled. It's a pretty safe bet that by the time you're at a receptacle it's HRC 0, so no label's needed.
John M
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Where you have 480V 3 phase receptacles throughout your plant feed from MCC's or panelboard it is entirely likely that they do have a higher than 0 HRC fault level available.
 
labeling receptacles

labeling receptacles

Let me clarify my statement.
I'm not suggesting that 480V welding receptacles go unlabeled, by any means.
I am suggesting that a facility's Electrical Safety Program should be set up to train folks to recognize 120V receptacles as HRC 0.
I don't believe it's the intent of 70E that arc flash labels be provided for all receptacles in a facility. We have to manage Electrical Safety to a reasonable level, and not burden facility owners with excessive requirements. Sure, if there's a receptacle that's interacted with on a regular basis, then include that in the analysis and label with incident energy levels.
John M
 
mayanees said:
Let me clarify my statement.
I'm not suggesting that 480V welding receptacles go unlabeled, by any means.
I am suggesting that a facility's Electrical Safety Program should be set up to train folks to recognize 120V receptacles as HRC 0.
I don't believe it's the intent of 70E that arc flash labels be provided for all receptacles in a facility. We have to manage Electrical Safety to a reasonable level, and not burden facility owners with excessive requirements. Sure, if there's a receptacle that's interacted with on a regular basis, then include that in the analysis and label with incident energy levels.
John M
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And like I mentioned earlier, conditions of an installation can result in a 120 volt receptacle having more potential incident energy than some 480 volt receptacle at some other location. So I don't fully understand any concept of assuming all 120 volt receptacles pose little or no threat. Generally speaking the 480 volt receptacle will likely have more incident energy, but that does not mean it always will.

Two identical receptacles of any voltage can be located right next to each other and have very different potential incident energy levels if connected to different sources with different characteristics. Like say one is connected to utility supply and another one is connected to an on site source.
 
How about a 20 amp -- 3 phase twist lock outlet 208Y ?

We did a job with 100 of those all around the plant. Some very close to the panel.
Workers use them all day long with portable production equipment.
 
Arc flash hazard also has to do with the voltage of the circuit. As far as I have read, and been to numerous classes etc, 120V is not considered a high enough voltage to sustain an arc and I believe this is in IEEE 1584. Remember that you have to have an arc that does not extinguish at the first Zero crossing of the voltage. Someone like Lazlo probably has more dealings with IEEE and could answer more completely.

A really good resource for any and all things arc flash is Brainfiller's forum:

http://arcflashforum.brainfiller.com/
 
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I just looked at IEEE 1584 and the model used for arc flash is for systems:

"Voltages in the range of 208 V?15 000 V, three-phase" with alternate models used for >15kV.

I don't know if any of the engineering software such as SKM or ETAP will calculate at voltages lower than that but IEEE has no model that I know of to do so.
 
BPoindexter said:
Arc flash hazard also has to do with the voltage of the circuit.
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But not all to do with voltage. Arc flash is really more about incident energy which is determined by voltage, current, and time. Lower voltage will extinguish in faster time as it will not sustain an arc as easily as a higher voltage with all other conditions remaining the same, But at same time you can have lower voltage with a higher incident energy level than you may have with a higher voltage and lower capacity supply.

Electric fence charger is a very good example of this.
 
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