As you enter the design process for your cable and wire assembly, UL certification will play an important part in manufacturing your product.
You’re likely already familiar with this third-party certification company and understand the UL logo means public safety requirements are being met as designated by stringent testing standards. Using UL listed and UL rated components (more on the difference in a minute) for cable assemblies can protect your product quality, help you acquire UL listing for your final product and improve overall traceability.
But as with many manufacturing certification programs, it can be confusing to wade through the terminology and understand exactly what terms are relevant to your product.
In this article, we’ll walk you through:
UL recognition refers to raw components for the construction of a larger product or system. Think of raw wire and cables, connector systems, terminals and board components. They bear the backwards “RU” marking and are suitable for general purpose use.
On the other hand, UL listed refers to a complete standalone product that has passed UL’s safety testing with the intended use in mind. Examples include consumer goods like microwaves, printers or an external power supply. These components will also have the “UL” symbol you’re likely familiar with.
The main difference between the two is how UL performs the safety testing. UL can only “list” a product if they can test the specific function of the item — that way, they can verify performance in those exact environmental parameters. With raw components, UL can’t know every possible application in which the item could be installed, so the testing is more general.
However, both terms can actually apply to raw cable. This may not make sense at first because you would think of wire and cable as raw components, part of a larger product.
But some cable is indeed tested for a specific application and environment: There’s VW-1 through VW-6 flame retardancy tests, CMP for drop ceiling installations and CMR for in-wall installations. For equipment production requiring cable assemblies (that’s what we do at Multi-Tek), flame ratings will be the most relevant UL listings.
Improved safety and reliability
Fires and equipment failure due to the use of poor materials is a possibility — and not something you want to risk. Choosing UL listed or recognized components protects against potential hazards and assures that all components are genuine and meet safety standards.
Easier to achieve UL listing for your final product
To attain UL listing on your end product, your cable assembly manufacturer must document and prove to UL that all the components in that assembly are recognized or listed. So, it follows that this process will go much smoother if you’ve already chosen components that are vetted by UL.
(Side note: Even if you’re not seeking UL listing, this will help improve your component traceability, too — an advantage to any manufacturing process.)
A cable assembly without a UL recognized mark could lead to a much costlier and time-consuming inspection process.
The UL inspector will want to see evidence that recognized components are used, otherwise they’ll subject the assembly to additional tests — cutting into your budget and risking deadlines. You can avoid this by using UL recognized and listed materials.
Having a UL recognized component mark on your cable assemblies does not mean that it is fit for any possible environment. Care should be given to choose components that meet all your environmental requirements — here’s our general guidelines to get you started.
The most important considerations are temperature exposure, flame test requirements and voltage, as the majority of UL ratings specify their suitability as it pertains to these three characteristics.
For hook-up wire selection, we steer customers to one of three different UL wire types:
For jacketed multi-conductor cable, the most commonly used is Appliance Wiring Material (AWM) 2464. This general purpose cable is UL recognized and rated to 300V.
Environmental considerations also play a part. Will the cable be inside an enclosure or exposed? What are the regulatory requirements for the sale and operation of the finished equipment, if any? Will it be exposed to unusually high temperatures or voltage?
For example, additional flame retardancy (VW-1 through VW-6, as mentioned above) is necessary if your cable will be installed in a plenum or riser environment, or if it’s going to be used as the power cable for your assembly.
Finally, as we mentioned earlier, some cabling will carry UL listing (instead of just UL recognition). This means it has been tested and is suitable for a certain environment — just make sure that the listing it carries actually matches your application. For instance, UL 817 is the standard for power cord sets. Choosing UL 817 rated cable would not make sense for an application other than designing a power cord set.
These guidelines will get you started and are best paired with the expertise of a knowledgeable supplier.
They can offer recommendations to ensure cables are not underrated for your application, but also avoid overrating products to prevent unnecessary BOM costs for your project.
So far, we’ve given you a foundation for considering UL recognized and approved components for your cable and wire assembly.
We’ll get your design to the finish line.
A Multi-Tek cable assembly expert will take a look at your design, make recommendations based on your application and help you achieve a product that meets your safety and UL listing needs. Get a custom cable assembly quote.
We’ll provide you with a fast quote (standard time is three days, can be as quick as same-day) and recommend manufacturability improvements.
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