what is SCCR if it doesn't prevent arc flash?

[Deltaforce]

Assuming you mean Professional Engineer, there are far more installations designed and installed by contractors and electricians than ones designed by PE. And even there the mechanical and electrical PEs often don't talk to each other so equipment with SCCR far lower than the available fault current is specified by the mechanical engineer.

But inspector of the install?
They also miss?

 

[don_resqcapt19]

But inspector of the install?
They also miss?

almost all the time

 

[petersonra]

Tangentially related to this subject... In article 440 (Air-Conditioning and Refrigerating Equipment), article 440.10 requires the SCCR to exceed the available fault current on motor controllers or industrial control panels of multimotor and combination-load equipment. My question is...what motors does this generally include and exclude? My niche is office / K-12 / government / healthcare...not so much industrial/manufacturing/etc.
* chillers, condensing units, cooling towers - obviously yes
* pumps related to such equipment - ??
* packaged air handlers / RTUs that include integral cooling - obviously yes
* packaged air handlers that push heated/cooled air, but do not include integral cooling - ??
* exhaust fans - assume no
* commercial kitchen freezer and coolers
* what else?

(I am aware of the similar requirements in 620.51 for elevator control panels. And of course switchboards, switchgear and panels. Mainly interested in what motors need to be remembered.)

Thank you!

SCCR does not apply to loads like motors at all. Only to the upstream control equipment and to the equipment containing protective devices such as circuit breakers, but not the actual protective equipment.

And to respond to another post, many times devices have limitations on wire sizes that restrict the SCCR. Usually larger wires have higher SCCR in these cases, while smaller wires may have just the default rating. You have to look it up and not rely on blurbs that say 100kA SCCR and #12-4/0 wire. Its quite possible the SCCR with #12 is 10 kA.