I'd like your thoughts on which electrode configuration these lugs fall under. I'm thinking the tops of the lugs and the bolt openings could fall under 'HCB' based on figure G.40 (of 1584 2018) and figure G.43.

I'm curious though if the horizontal distance of these lugs compared to the length of the horizontal electrodes used in testing is enough to be comparable. I don't recall any guidance in the standard.

Anyway I'd really appreciate any feedback you could offer.

Anyone?

Looking at the picture, I think that the configuration that you would get the "best" answer is either VCB or VCBB.

I grabbed the attached picture from the Brain Filler page - Source (I tried to put it inline but this forum theme doesn't autoscale images)

Like you mentioned, the lugs likely aren't directing the arc out of the box. I think that it is more likely that the arc will propagate towards the side of the box and then out/down. There will be reflection off the back of the box and side.

The energy distribution would be the same as VCB and VCBB, but I think its going to be closer to the real world answer than HCB; without under-estimating.

I would like to hear some other people's thoughts on this too.

Cheers,

Jeff M