vicdog wrote:
PaulEngr wrote:
But I haven't seen it occur horizontally from section to section, nor from section to section within switchgear, nor from one box to another via conduit. So no, no reason to assume that arc flash in a panel in the same room connected by conduit is different.
Thanks for the reply. Can you clarify above? Are you saying I can label that panel connected via conduit as <1.2cal?
I am planning on labeling the entire switchboard per the incoming bus arc flash energy.
Just as I said. Looking at switchgear, even though there are openings in the back where the bus bars pass from one section to the next, I haven't seen damage propagate from one section to another. The same is also true with equipment of any kind and nearby enclosures connected via conduits. I could see it happening if the diameter of the conduit is close to the area of the side of the enclosure it is connected to but that is not generally the case.
I have not seen arc flash propagate from the medium voltage to low voltage compartments within switchgear. I don't know the dimensions of your equipment but that's probably the closest comparable to what you are describing.
I have seen arc flash propagate vertically within an MCC but not from one section to a totally different section, even though the relative size of the openings for the bus bars where the splice plates are located is a lot larger. So this should give you some idea of dimensionally where an enclosure is and is not a separate enclosure.