Housing Requirements

[MW_EE_2015]

I'm looking at getting 6 VFDs (480v, ~75hp, NEMA 3R) and putting a small building around them with lights to keep the elements off the technicians who need to service them.

I know the NEC covers spacing requirements in 110.26, but does anyone know of a code requirement for what the building should be made of? Customer is pushing for fiberglass due to its availability and price point, and while I'm not opposed to it I worry about how it might hold up to an arc flash should one of the drives fail catastrophically. I know this question might fall more under building code, but was hoping someone here might be able to point me in the right direction. I've checked my state building code, but they do not seem to cover this topic at all.

 

[Omaha Geek]

The NEC does not specify the building materials to be used around VFDs; however, it is crucial to consider the material’s resistance to arc flash. Fiberglass may be available and cost-effective, but its resistance to arc flash should be evaluated. Materials with a specific rating for protection against electrical arcs are recommended. It’s advisable to consult with a local authority having jurisdiction (AHJ) or a professional engineer to ensure compliance with all relevant codes and safety standards12. Additionally, IEEE C37.20.7-2017 provides guidelines for testing equipment resistance to arc flash, which might be useful in assessing the suitability of materials3.