Is it ever ok to work on exposed live parts per 70E?

[jim dungar]

The arc flash labeling starts at 1000 amps and the arc flash reduction rule starts at 1200 amps,

It is my opinion that the "applicable industry practice" will require the actual incident energy level and arc flash boundary on the equipment. The NEC wants to require you to use the 70E label, but the NFPA rules do not permit on NFPA document to require the use of another NFPA document, hence the "applicable industry practice" part of the rule. If there is another "applicable industry practice", you could use that, but I don't think that there is another.

110.21(B) does not require any specific information. It simply provides requirements as to the type and installation of labels that are required by other code sections.

But NFPA 70E does not require incident energy levels, it still allows PPE selection only by Task being performed.

 

[David Castor]

it still allows PPE selection only by Task being performed

NFPA 70E allows two different methods - The incident energy method (calculations) or the Categories method. The Categories method involves using a series of tables in 70E based on type of equipment voltage level. There is also a table of various common tasks with a determination of whether or not "Additional Protective measures are required". That means PPE. So first you determine if PPE is required, then based on the type of equipment, the Category of PPE is determined.

BUT the big gotcha is in the notes in these Category tables. Use of these Categories is only valid up to a stated maximum fault current and a stated maximum clearing time. So in theory, in order to use this Category method you need to have an idea as to the fault current and the fault clearing time.

 

[don_resqcapt19]

But NFPA 70E does not require incident energy levels, it still allows PPE selection only by Task being performed.

I guess I just don't see that as an arc flash label and 110.16 requires an arc flash label. However, I don't think there is a definition of an "arc flash label"

 

[jim dungar]

However, I don't think there is a definition of an "arc flash label"

And that is the issue.