Arc Flash Analysis -- Energized Equipment

[timm33333]

I have a question about arc flash analysis. NEC 110.16 requires that labels are required for all equipment which is likely to be worked on while energized. The definition of energized equipment should come from the owner. But if owner does not provide this information, then how do we determine that on which equipment the energized work is possible?

Arc flash labels should be provided for indoor equipment like MCC, Switchgears, panels, etc. But Is it Ok to not provide the arc flash labels for outdoor equipment like transformer-terminals, motor disconnect switches, etc.? Thanks

 

[dik]

As a non-sparky I would think that if arc flash labels were required, it wouldn't matter if the equipment was indoors or outdoors, but I don't know for sure. I cannot comment on your other querys.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[davidbeach]

We certainly apply arc flash labels to outdoor equipment.

I’ll see your silver lining and raise you two black clouds. - Protection Operations

 

[timm33333]

Should arc flash labels be required for disconnect switches of motors and other equipment?

 

[dpc]

I'd suggest reading the requirements for labeling in NFPA 70E. There's no distinction between indoor or outdoor equipment. Labels are required for equipment "likely to be serviced or examined" while energized (going from memory).

There is an exception in 70E regarding the labeling requirement that you might want to look at as well, but there are a lot of restrictions on its use.

If you are a consultant doing a study and printing labels, I'd make a label for anything that you think requires one.

 

[BigJohn1]

how do we determine that on which equipment the energized work is possible?

Where is troubleshooting most likely to occur?

For example: Motor disconnects are likely to have energized troubleshooting (indoor or outdoor doesn't matter), and should be labeled. But a cabinet full of insulated splices is not, and might not need a flash label.

A dry-type transformer enclosure might be unlikely to need energized troubleshooting, but certainly the breakers on either side of it could.

 

[davidbeach]

A dry-type transformer...

That all depends on whether or not you want to perform IR scans of the connections while energized.

I’ll see your silver lining and raise you two black clouds. - Protection Operations

 

[Gr8blu]

I look at it this way: if the equipment requires input electrical power for me to able to test ANY of the functionality, it gets labeled. This applies to ALL equipment, indoors or out. If the owner of the equipment thinks I'm going overboard with the label thing, the next one to have to work to said equipment is going to thank me.

Also note that equipment will require labels if there is a possible arc flash hazard when it is operated under normal conditions - not only when performing maintenance. That might mean the outside of the device gets one label for its level of severity - and the inside gets another.

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