This guide overviews the practical differences between different types of UL certificates and advises on how to go through UL certification as a cable manufacturer. Individual buyers can also learn how to differentiate UL listings.

UL Listed vs. UL Recognized: What is the Difference?

There is a lot of confusion online when it comes to the difference between the terms UL listed and UL recognized. While products and components can more often be either UL-listed or UL recognized, electrical wire and cable can actually be both UL-listed and UL recognized. Sounds puzzling? Let's break this down.

• UL recognized is the term that refers to raw components of electrical systems and assemblies, including wire and cable, connector systems, and board components. 

UL-recognized components are the so-called General Tested Components because UL cannot predict every specific environment where they will be used.

• UL listed is the term that best describes complete assemblies and standalone industrial products, like vacuum cleaners, refrigerators, etc. "UL listed" means that UL could test the specific function the product was designed for.

However, raw wire and cable can also be UL listed. While it makes sense to think about wire and cable as a component, the difference is in what type of testing has been applied to the specific cable. If the cable has been tested only for general-purpose testing, it is UL recognized. If the cable underwent specific tests for performance in specific conditions, it is UL tested.

For example, if the cable went through a specific test like UL VW-1 Vertical Wire Flame Test, it is UL listed, as its performance has been tested for a specific environmental issue. UL-listed cables have a specific UL symbol on their package.

The cons of buying cables not listed by UL 

Cables not listed by UL are common and used in electrical work all the time. One common example is not-listed SOOW cable. However, choosing a cable not certified by UL may result in potential fire hazards and issues with hot/cold temperatures.

For manufacturers of finished products like microwaves, refrigerators, and vacuum cleaners, it makes sense only to use UL-certified wire and cable. This gives them a fast way to get their end product listed by Underwriter Laboratories. For example, your cable assembly will be fast-tracked for a UL listing if its individual components are recognized or listed by UL.

When UL tests the finished product or the cable assembly, they will end up separately testing individual components as well if they were not previously tested, so it will take them more time to complete all tests.

How to UL test cables?

The fastest way to get your cable certified by UL is to directly contact UL Solutions and partner up with them on a certification procedure. UL Solutions assist companies with all possible types of wire and cable testing. The testing is available for over 70 subtypes of wire and cable products.

Before applying for testing, you should choose the appropriate range of tests applicable to your particular product. After the tests are selected, study the requirements to complete the tests and make sure that your cables fit these conditions. Choose a certified testing laboratory near you and submit your cables for testing. If any non-compliances are detected in the testing process, it can be possible to address and fix them while the products are still in testing. After the product receives the certification, it is important to stick to the follow-up conditions on time not to lose the certificate.

NNC offers a broad range of cables that went through UL certification.