This directory lists 89 electrical enclosure manufacturers across the United States, from standard sheet metal fabricators to specialized providers of hazardous location enclosures. These US-based Companies, deal in custom, weatherproof, and NEMA-rated enclosures, thereby ensuring that your electrical. ETA Enclosures USA provides power distribution enclosures engineered for switchgear, transformers, and control panels. NEMA Enclosures Manufacturing of Texas, LLC 3.