Junction Box

[timm333]

If we put a terminal block in an enclosure, for example universal-enclosure of Schneider, then do we need to consider the short circuit rating of only of the terminal blocks, or short circuit rating of enclosures as well?

 

[7anoter4]

I don't know what could be the short-circuit withstand test of a junction box.UL-50 indicate a "pressure test" and could be sufficient for usually low-voltage short-circuit arc flash in a junction box. Of course if the employee opens the box cover he has to be equipped as per NFPA 70E:
"Standard for Electrical Safety in the Workplace". According to NEC the non energized metallic parts have to be grounded [see Art.250-122].The requirement for short-circuit test is for boxes containing fuses or breakers as switchgear or MCC and other.

 

[timm333]

Thanks 7anoter4. Another question comes to mind.

Why is it that the arc flash study is required for 480V MCC/switchgear, but is not required for a 480V panelboard?