Panelboard Interior Replacement ?

[WTO]

I have told that panelboard interiors, not marked for use in the existing enclosures, revert to a short-circuit current rating of 10,000 AIC. If a short-circuit current rating above 10,000 AIC is required, a Field Evaluation shall be performed by UL to determine the actual short-circuit current rating of the new panelboard interior and existing enclosure combination.

Does anyone know where this is addressed in the code?

My understanding was that if the existing backbox was the same size or larger than what is required for a new panel, there was not a problem.

 

[jim dungar]

I have told that panelboard interiors, not marked for use in the existing enclosures, revert to a short-circuit current rating of 10,000 AIC. If a short-circuit current rating above 10,000 AIC is required, a Field Evaluation shall be performed by UL to determine the actual short-circuit current rating of the new panelboard interior and existing enclosure combination.

Does anyone know where this is addressed in the code?

My understanding was that if the existing backbox was the same size or larger than what is required for a new panel, there was not a problem.

The code never says this directly. The code says the AHJ must approve all equipment, UL labeling is a tool that can be used for that evaluation.

There are many listed "OEM interiors" that are intended to be installed in custom enclosures yet they carry the same SCCR as their identical cousins that are sold as assembelys. And in one catalog I looked at the manufacturer of "replacement interiors for mounting in existing boxes" has no mention of any change in SCCR.