Over the years, Nema Enclosures has produced thousands of custom enclosures that are UL508A listed and individualized for each customer’s needs. Oftentimes, customers require a UL listed enclosure because:
- Customer or Industry Requirements
- End-User Specifications: Some customers, especially large industrial clients, require UL-listed enclosures as part of their purchase requirements.
- Industry Standards: Certain industries (e.g., oil & gas, food processing, hazardous locations) may mandate UL certification for compliance.
- Electrical Code and Regulatory Requirements
- NEC (National Electrical Code) Compliance: If your panel is installed in a jurisdiction that enforces NEC, a UL listing may be required. NEC Article 409 requires industrial control panels to be listed or evaluated by a Nationally Recognized Testing Laboratory (NRTL), such as UL. NEC Article 110.3(B) states that electrical equipment must be installed and used according to its listing and labeling instructions.
- OSHA Requirements: OSHA often requires control panels and enclosures to be NRTL-certified for workplace safety.
- AHJ (Authority Having Jurisdiction): Local electrical inspectors may require UL listing as proof that your enclosure meets safety standards.
- Environmental Conditions & Safety Risks – if your enclosure is exposed to:
- Outdoor weather → May require UL 50/50E for environmental ratings.
- Heavy washdowns (food processing, pharmaceuticals, etc.) → May require UL Type 4X or UL 50E stainless steel enclosures.

Underwriters Laboratories (UL) is a global independent safety science company with more than a century of expertise innovating safety solutions from the public adoption of electricity to new breakthroughs in sustainability, renewable energy and nanotechnology. As a global safety science leader, UL Solutions helps companies to demonstrate safety, enhance sustainability, strengthen security, deliver quality, manage risk and achieve regulatory compliance. Recall, that NEMA ratings are self-declared, but UL certification requires independent 3rd party testing. If you are using a pre-certified enclosure and modifying it, you may need UL follow-up certification to maintain compliance. When Nema Enclosures fabricates custom enclosures, we can work with you to ensure that the design meets UL criteria and include certification.
