Underwriters Laboratories Listing & Testing

04.21.22|Rudi Rodriguez
Underwriters Laboratories Listing & Testing


EPI-Electrical Enclosures & Engineering began 55 years ago in San Antonio, Texas. As a full-line manufacturer, we offer six major National Electrical Manufacturer Association(NEMA) product groups: NEMA 1, NEMA 3R, NEMA 4, NEMA 4X, and NEMA 12 Enclosures and Wireways. In addition, we offer a full range of Secondary Buss products. These diverse product groups have applications in the commercial, contractor, institutional, utility, medical, robotic, telecom, and electronic industries.

As a manufacturer, we distribute our electrical products through a national network of Electrical Distributors such as CED, Crawford Electric Supply, Dealers Electric Supply, Elliott Electric Supply, Graybar Electric Supply, Hill Country Electric Supply, The Reynolds Company, Summit Electric Supply, Winsupply, and many others.

To date, we have fabricated over 40 million NEMA enclosures, wireways, and Bussed products. Plus, we have had one hundred and sixty thousand shipments around the country and the world. Also, we’re proud of our engineering department that has provided engineering and design for all our products. Important projects we have been a part of are: Sea Wolf II with the US Navy, Space Shuttle Endeavor with NASA, and the world’s largest robot for the US Air Force.

Also, our engineering Department has developed ongoing relationships with many state, and national utilities and private engineers. Over the years these relationships have become necessary as submittals for NEMA design, specifications, and engineering is required for acceptance and approval.

Manufacturing Standards

For 55 years, EPI has strictly followed NEMA, NEC, and JIC standards for product design and construction of all our NEMA Product groups.


Our engineering is driven by and developed using NEMA standards. Our engineering department works with distributors, contractors, private and public utilities, utility engineers, and private electrical engineering firms throughout the country to provide expertise in product design and application. We offer informative documents such as specifications sheets, product catalogs, and engineering drawings. We’re also called on to design specialty products for unique applications. We’ve also worked with laboratories and institutions such as NASA, Southwest Research Institute, the U.S. Department of the Navy, and the U.S. Department of the Air Force.

Underwriters Laboratories Listing & Testing

As EPI continues to grow and improve its product lines and provide quality products to our industry, we have seen the need for having our products listed by Underwriters Laboratory. This independent laboratory will test our major product lines for compliance with NEMA Type Standards of manufacturing. Typically, there is initial testing of our submittals at their facilities and then an ongoing quarterly visit to our plant for sample testing.

Arrangements were made early this year and it is expected that by June 2022, U.L. will be complete with its rigorous testing. Shortly after, we will make public announcements and begin labeling the U.L. brand on our products. We have great expectations for this new chapter in our business and feel our electrical industry will also be a beneficiary.