NFPA 70E arc flash rules.

[powerpete69]

Hey folks,
Formally I have been doing arc flash studies showing every single bus down to the 208/120V panels and printing arc flash stickers and reports for everything.

Now I have recently been told that we don't need to do that, instead we just need to show worse case scenarios from the MCC's or large distribution panels. In other words, if all the loads from an MCC are less than 4 calories or less, they are simply PPE 1 and don't need to be labeled.

So the question is this, is this true? And if it is true, where does it specifically state that in NFPA 70E?

 

[jim dungar]

What you heard is not part of NFPA70E.

 

[xptpcrewx]

A lot of people do this which is just wrong and lazy. According to the NEC Arc-Flash labels need to be provided anywhere equipment may require examination, adjustment, service or maintenance while energized.


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[powerpete69]

Unfortunately, I hear what you are saying.

Here is the direct quote from a reliable engineer:

"The last edition of NFPA 70E absolved you from having to put labels on everything, but you needed to have arc flash and electric shock data available for the equipment. "

Boy, sure would would like to see the part that absolves you!!!

If anyone has access to that statement.....please post the section!!!!! Fingers crossed!!!

 

[jim dungar]

"The last edition of NFPA 70E absolved you from having to put labels on everything, but you needed to have arc flash and electric shock data available for the equipment. "

If anyone has access to that statement.....please post the section!!!!! Fingers crossed!!!

You won't find that statement in any NFPA publication. What you will find is a comment that allows you to forego labels directly on equipment when it is impracticable such as when the arc flash label would coverup other required labeling, a common example is 30A 240V disconnect switches.

You must still determine the appropriate PPE even though the label is not directly on the equipment, which is not what was said in the OP.

 

[powerpete69]

130.6(H) in NFPA 70E, Exception 2 below. Exception 1 is quite interesting as well.
Our plants are only worked on by the most qualified of persons with all safety measures.
This is 2018 NFPA 70E:

Δ
(H) Equipment Labeling. Electrical equipment such as switchboards,
panelboards, industrial control panels, meter socket
enclosures, and motor control centers that are in other than
dwelling units and that are likely to require examination,
adjustment, servicing, or maintenance while energized shall be
marked with a label containing all the following information:
(1) Nominal system voltage
(2) Arc flash boundary
(3) At least one of the following:
a. Available incident energy and the corresponding
working distance, or the arc flash PPE category in
Table 130.7(C)(15)(a) or Table 130.7(C)(15)(b) for
the equipment, but not both
b. Minimum arc rating of clothing
c. Site-specific level of PPE
Exception No. 1: Unless changes in electrical distribution system(s)
render the label inaccurate, labels applied prior to the effective date of
this edition of the standard shall be acceptable if they complied with the
requirements for equipment labeling in the standard in effect at the time
the labels were applied.
Exception No. 2: In supervised industrial installations where conditions
of maintenance and engineering supervision ensure that only
qualified persons monitor and service the system, the information
required in 130.5(H)(1) through 130.5(H)(3) shall be permitted to be
documented in a manner that is readily available to persons likely to
perform examination, servicing, maintenance, and operation of the
equipment while energized.
The method of calculating and the data to support the information
for the label shall be documented. The data shall be
reviewed for accuracy at intervals not to exceed 5 years. Where
the review of the data identifies a change that renders the label
inaccurate, the label shall be updated.
The owner of the electrical equipment shall be responsible
for the documentation, installation, and maintenance of the
marked label.