Just curious if this has ever been addressed. Once a dead front has a filler plate inserted to fill a space, is this just protecting from exposed live parts but now allowing the equipment to dissipate an arc blast toward a potential person? Do they derate the equipment?

They are required and do not derate the panel in any way. Since they are not part of the panel electrically they have no impact on the SCCR. You may use properly rated breakers or the appropriate hole covers but one way or another all openings must be covered to guard against accidental contact of energized circuit parts.

I had this same question in another forum, they suggested I come here. I understand from others as well that there is no impact on SCCR because that is for withstanding a fault, not containing an arc event.

Would an "appropriate" filler be any made to fit or must they be OEM? I believe that an arc blast is not considered when developing the SCCR, but a non metallic filler plate snapped into an opening does seem to create a more dangerous potential. I like an unused breaker.

Thank you for the reply!

I don't think I have seen a manufacturer supplied metallic filler plate in probably close to 40 years.