UL Listed vs. UL Certified: Understanding the Difference
Every business has the responsibility to ensure safety and compliance with the law in the devices and components that it uses. That’s where safety and compliance testing organizations come in. These third-party organizations perform rigorous testing on all kinds of materials and components to verify that they meet the relevant standards.
In the U.S., the largest and most widely known safety testing organization is called UL. “UL Listed” and “UL Certified” are two common terms you might encounter when evaluating electrical enclosure boxes for use in your electrical systems and electronic devices. “UL Recognized” is an additional UL designation that’s also relevant in electronics design.
Here, we’ll look at the question of UL Listed vs. UL Certified and help you determine which type of certification is most appropriate for your needs. We’ll also take a quick look at other designations like UL Recognized and evaluate how they can fit into your compliance requirements for electrical enclosures.
What Is UL? A Quick Overview
UL, formerly known as Underwriters Laboratories, is an independent non-profit testing lab for consumer, commercial, and industrial products. The company has existed for over 100 years, and billions of products around the world carry marks such as UL Listed to verify that they have been tested to certain standards.
Many different types of devices and components need to be UL tested to verify that they conform to various industry safety standards. Anything from plumbing equipment to fire suppression systems to consumer beauty products may require UL testing. But how does this testing work, and what should you look for in a product’s UL certifications?
How UL Product Testing Works
Businesses submit their products to UL for testing and work with lab specialists to ensure that their products receive a thorough and accurate evaluation. The testing procedures used by UL vary considerably from one application to the next.
Each testing process is designed to verify that a representative sample of the product meets the industry standards that the manufacturer has requested verification for. In some cases, UL will test products using its own laboratory facilities. Other times, UL will allow a manufacturer to submit results from its own testing or from another third party if the manufacturer can verify that the testing meets UL’s standards.
Once a product has passed UL’s testing procedures, UL authorizes the manufacturer to use the appropriate UL mark on that product. UL has numerous marketing guidelines for how and when businesses may use a UL mark on their products, and it’s critical to verify that your marketing materials conform to these standards.
Furthermore, UL operates a Follow-Up Services program that periodically inspects the manufacturing processes of products that they have previously tested. This helps ensure that manufacturers maintain high standards of quality even after their products have completed initial UL testing.
Why Some Electrical Enclosures Need UL Testing
Electrical enclosures need to be UL tested if they’re intended to conform to standards such as NEMA ratings or IP ratings. The U.S. does not have a regulatory authority that preemptively tests products for compliance with these standards. Instead, businesses are responsible for certifying their products’ compliance using a third-party testing authority such as UL.
Despite the lack of preemptive testing from regulators, industry standards like NFPA 70E and the NEC require that electrical devices be protected by enclosures with certain NEMA ratings and/or IP ratings. Failure to use enclosures that meet these standards can result in systems that are out of compliance and unsafe.
That’s why most manufacturers’ compliance departments require device designers and engineers to specify electrical enclosure models that have been certified by UL. UL testing is crucial for mitigating the risk posed by a potentially faulty electrical enclosure, and insurance companies may require the use of UL-certified products.
In fact, UL has even developed its own standards for electrical enclosures and control panels. These include UL 508A, UL 50, and UL 50E, all of which reference frameworks like the NEMA standard and ensure rigorous testing of electrical enclosures. UL 94 is another important standard that refers to an enclosure’s ability to resist burning and melting under conditions of extreme heat.
What Does UL Listed Mean?
First, what is UL Listed? As officially defined by UL, the UL Listed mark signifies “that UL has tested representative samples of a product and determined that the product meets specifically defined requirements.” UL Listed is the most common type of UL mark, and it’s the one that you’ll find on Polycase enclosures.
Generally, the UL Listed mark applies to finished products ready for the end-user. Items like laptop and phone chargers are perfect examples of where an average consumer might find UL Listed marks. The designation also applies to items like electrical enclosures, and hundreds of UL Listed electrical boxes are available from Polycase in a variety of electrical enclosure box sizes.
A UL Listed mark can stand by itself, or it might be a combination mark that indicates compliance with multiple international standards. For example, a UL Listed mark that contains a “C,” a “US,” and an “EU” indicates that the product has been tested to meet relevant standards in Canada, the U.S., and the European Union. (See the image of the marks above.)
UL has announced that it will eventually transition away from the UL Listed mark in favor of its all-in-one UL Enhanced Certification mark. Fortunately, the UL Listed mark is still used on millions of products in current production, and there are no immediate plans to phase it out. You can count on a UL Listed enclosure to provide the gold standard of reliability and performance.
What Does UL Certified Mean?
The term “UL Certified” has multiple meanings. First, the term is sometimes used as a general term in reference to any and all types of UL certifications, including UL Listed and UL Recognized Components. However, when you’re evaluating component compliance, it’s important to look at specific types of UL certifications.
The most correct and specific use of “UL Certified” refers to UL’s Enhanced Certification mark. If you see a badge on a component or device that says “UL Certified,” it’s part of the Enhanced Certification system. This system consolidates multiple types of safety and performance information into a single mark.
Among other changes, the UL Enhanced Certification badge contains information on the specific standards that a product has been tested for. The Enhanced Certification badges contain a descriptor of the standards originally part of the UL Classified badge, such as SAFETY, ENERGY, or MARINE. These descriptors refer to sets of testing standards designed to measure performance in specific contexts.
UL Enhanced Certification badges also contain the manufacturer’s UL file number and an opportunity to add a QR code for fast and easy traceability. Remember that although UL is eventually transitioning fully to the UL Certified badge, the organization has emphasized that the original marks remain valid and acceptable in their usual contexts.
What Does UL Recognized Component Mean?
UL Recognized Component is a different type of certification that’s used for certain types of industrial components. It applies only to individual components, such as transistors and printed circuit boards, that are elements of larger systems. You won’t find it on finished devices or consumer products.
Some Polycase components, including some of our enclosure accessories, are UL Recognized Components rather than UL Listed. This distinction reflects that these components are designed as accessories for enclosures rather than as independent units. However, they’re still made to meet high standards that allow them to function as part of a UL Listed system with our enclosures.
The UL Recognized Component mark looks substantially different from other UL marks, so it’s almost impossible to confuse it. UL has not announced any plans to make UL Recognized a component of the UL Enhanced Certification system.
UL Listed vs. UL Certified: Which Do I Need?
Ultimately, since UL Listed and UL Certified overlap significantly, the most important answer is to select an enclosure that lists a UL rating for the specific standard you need compliance with. Polycase offers a huge variety of UL Listed enclosures with common ratings like NEMA 4X and IP68.
We’ll continue to submit our enclosures for testing and verification through UL to ensure that our customers have 100 percent confidence in every Polycase product. We’ve got one more important tip, however: When choosing an electrical enclosure, make sure to verify its UL mark.
How to Verify a Product’s UL Mark
One of the biggest advantages of working with UL is that it’s easy to check the UL testing data for any given component. A manufacturer that submits its products to UL for testing should have at least one UL file number that allows you to easily find the manufacturer’s products in the UL certification database.
The UL file number is the letter E followed by a six-digit number. When a manufacturer has products that fall into multiple categories of UL certification (such as UL Listed and UL Recognized), the manufacturer will have a different file number for each certification type.
Every Polycase product with a UL certification includes our UL file number on its product description page. Once you have the file number, simply enter it into UL’s Product iQ database. You’ll be able to access the product’s UL testing data results and its official certificates of compliance from UL.
We’re always thrilled to help our customers find any information they need about our products, including their UL listings and testing data! If you’ve got questions about any Polycase model, feel free to reach out to us at 1-800-248-1233, or contact us online. Or, get started by browsing our full selection of UL electrical boxes to see every UL Listed enclosure that Polycase has to offer.
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