jessicatonn . Jun 22 . 9 months ago

EV Charger UL Listing: What Does it Mean When an EV Charger is UL Listed?

As electric vehicles (EVs) make their way into the mainstream, chances are you already have or will consider if a hybrid or all-electric car is right for your next big purchase. Being an EV owner offers several benefits such as skipping the occasional stops at the gas station, lower maintenance costs, and overall improved driver and passenger safety. Soon just about every car will likely have an all-electric version available. When choosing an EV for your home, you may come across standards such as “EV charger UL Listed.” Fortunately, we aim to shed light on that particular topic and how it influences EV ownership in this piece.

Advances in charging technology have undoubtedly driven the steady surge in EV popularity. With a simple upgrade to the standard Level 1 (L1) charging cord that comes with a new EV, you can enjoy overnight charging of an empty battery to maximum capacity. Level 2 (L2) chargers are by far the most common type of electric vehicle supply equipment (EVSE) because the higher voltage supplied by these systems enables faster charging speeds. For first-time EV owners, an L2 EV charger is, therefore, the ideal choice. To learn more about the differences between L1 and L2 charging, read our blog: All You need to know About Level 2 EV Chargers.

However, with advanced EV charging equipment comes a greater risk of fire hazards. Especially if you are looking to purchase and install EVSE from a third-party manufacturer. Faulty manufacturing, improper installation or operation, degraded wall outlets or equipment can all drive electrical shorts, improper protection against power surges, or other malfunctions. 

One of the clearest and easiest ways to know you are purchasing a reputable EVSE is to look for the official “UL Listing” mark. This mark indicates the product has been certified to meet national scientific safety and quality standards. In this article, we will dive deep into what exactly UL Listing is, why it is important specifically for EV chargers, and several UL standards pertaining to EV chargers.

What is EV Charger UL Listing and Why is it Important?

Underwriters Laboratories, also known as UL, is one of the worldwide safety certification companies approved by the U.S. Occupational Safety and Health Administration (OSHA). Part of the list of nationally recognized testing laboratories (NRTL) maintained by OSHA, UL provides third-party safety tests for a range of technologies including EV chargers. It is important to note UL was founded over 100 years ago, now operates in 125 countries, and has over 64 testing laboratories earning it a rock-hard reputation in the eyes of the public.  

For a product to maintain UL Listing status, any changes in form, fit, or function will require a re-certification. NRTLs will also randomly inspect EV charger manufacturers to ensure the production process is consistent with the tested and certified samples. The certification process is costly and time-consuming but worthwhile for EV charger manufacturers to invest in.

The National Electrical Code (NEC) Article 625 defines standards and requirements pertaining to the installation of EVSEs. Some of the specifications include the following:

  • Listing of all electrical components – including materials, devices, and fittings associated with the equipment
  • Interlock to de-energize the cable whenever disconnected from the vehicle
  • A safety system that automatically de-energizes equipment if exposed to force or strain that can physically puncture the cable or exposed live parts
  • EVSE must have a “listed” system for protection against shock

To be “UL Listed” actually goes above and beyond the simple UL Mark. Obtaining a UL Mark, while important, is generally less stringent and testing is performed by the product’s manufacturer according to UL’s procedures. On the other hand, “UL Listing” is reserved for end products used by consumers. In fact, UL itself will perform an exhaustive suite of tests in accordance with NEC Article 625 on EVSEs to consider them “listed”. 

It is not mandatory for EVSE manufacturers’ products to become UL certified or listed. If you want the highest level of safety, it is recommended to opt for a UL Listed charger.  Any UL Listed product will contain the following elements: (1) the UL mark (2) the word “Listed” nearby the UL mark logo, (3) a unique control number, and (4) a product name. 

Do Chargers Need to be UL Certified?

There are currently no laws stating that EVSE products need to be UL certified. In commercial settings like a hotel or public parking garages, there may be business requirements mandating the installation of UL certified equipment. Especially for a home installation, there is nothing preventing you from purchasing a non-certified charger so it’s important to be aware of this fact when shopping for an EVSE.

UL Certified is really an umbrella term that contains different UL categories such as UL Listed, UL Recognized, and UL Classified. Technically, being “UL certified” means that the product will fall in one of these three categories. If you are purchasing a UL Listed charger, rest assured that you are also buying a UL certified product. 

The categories of UL Recognized and UL Classified apply to slightly different types of material than EV chargers. UL Recognized covers non-customer-facing parts and machinery used to manufacture products. For example, you could have an EV charger produced by UL Recognized machinery, containing UL Recognized parts, but not actually be UL Listed or UL Classified.

On the other hand, UL Classified applies to end-user products but only tests for specific properties under a limited range of conditions. In other words, UL Classified involves a more limited scope than that required for UL Listing. 

How can You Know if Your Charger is UL Certified?

Depending on your geographical region, UL provides a variety of easily recognizable markings and logos to indicate what type of UL Certification the product carries. Specifically, in North America, UL Listing marks can be found on household appliances, computer equipment, fuses, circuit breaker boards, smoke and carbon monoxide detectors, fire extinguishers, personal floating devices, bullet-resistant glass, and EV charging stations to name a few. 

UL Listing Marking will contain all four design elements: 

  • UL in a circle symbol
  • The word “LISTED”
  • The product name
  • Serial/issue number or alphanumeric control number

It is important to watch out for deceptive markings. Any marking not containing all four elements cannot be considered “UL Listed” and could indicate an untrustworthy product or manufacturer. 

Did you know that many EV chargers sold on Amazon do not have safety certification? And while customer reviews can be indicative of quality, they are not an accurate depiction of product safety. This is precisely because there are no legal requirements forcing Amazon to sell certified equipment. While this is great from a customer perspective, widening your search and allowing you to access a range of price points, it does introduce more uncertainty when it comes to online shopping for your EV charger. 

What does it Take for a Charger to be UL Listed?

In order for an EV charging system to be UL Listed, it must comply with national industry standards outlined in NEC Article 625 which outlines the design, functional, and safety requirements for installation of EVSEs. As mentioned above, the UL Listing category is an involved process requiring a UL representative to perform safety tests in accordance with national regulations. 

In general, the UL certification process starts with the EV charger manufacturer sending representative samples to a UL lab for testing. There, the samples will be inspected for their construction, several tests are run on the product under real-life use conditions, and finally, the performance of the device is evaluated. Next, UL will issue a report back to the manufacturer informing them of any gaps in the design, manufacturing, performance, and safety of the product with respect to the industry best practices and national standards. This report will also state any follow-up tests required if new and improved samples are submitted. Only once the sample passes all of the tests will the product be deemed UL Listed.

While the process is involved and time-consuming, often taking several months to complete all testing, it is a worthwhile investment for EVSE manufacturers to make. Both from a tax-incentive and customer safety perspective, UL Listing status will allow manufacturers to take advantage of government-sponsored tax incentives as well as protect against liability claims. As an EV owner or potential buyer, nothing is more valuable than your peace of mind knowing you are utilizing safe equipment in your home. 

In your search for all things EV safety, you might come across the various standards UL has published to guide their third-party testing. UL standards 2202, 2594, 2251, 62, 2231-1, 2231-2, and 9741 cover EV charging systems. In the next section, we will briefly describe the scope of these standards.

UL 2202

UL 2022 is titled “Standard for Electric Vehicle (EV) Charging System Equipment” and specifically applies to equipment that supplies DC voltage, also known as UL category “FFTG”. This category includes Level 3, or DC fast chargers, which can be found along major highways as opposed to someone’s home.

UL 2594

UL 2594 is the “UL Standard for Safety Electric Vehicle Supply Equipment” and applies to the UL category “FFWA”. These types of EV chargers supply AC current to the onboard charger and are classified as Level 1 or Level 2 chargers. These types of cord set chargers are most commonly used by EV owners.

UL 2251

The UL 2251 standard is titled “Standard Testing for Charging Inlets and Plugs”. This standard details the requirements for cover plugs, receptacles, vehicle inlets, and connectors. It actually does not dictate the exact design and configuration of the components so a wide variety of designs can be accommodated depending on the manufacturer.

UL 62

UL 62 is the “Standard for Safety Flexible Cords and Cables” and therefore covers EV charging cables in addition to several other applications of flexible cords.

UL 2231-1 & -2

Both UL 2231-1 and 2231-2 define “Personnel Protection Systems for Electric Vehicle (EV) Supply Circuits: Particular Requirements for Protection Devices for Use in Charging Systems”. UL 2202 and 2594 essentially require the EV charging system to include integrated “personnel protection systems” whose requirements are defined in UL 2231. In general, L1 and L2 chargers will feature a grounding mechanism whereas L3 fast chargers utilized “isolated” designs.

UL 9741

UL 9471 covers “vehicle to grid” or V2G storage. The concept of V2G storage, while not currently mainstream, contributes to a smart energy grid in which EV batteries are used to store power and supplement energy during peak demand window. In other words, during low-energy-demand hours of the day (such as in the morning), EV batteries are charged up to store the extra capacity and reversed when demand is peaked (for instance in the evening). The EV owner can control when the smart grid can access their battery capacity so as to not disrupt their own routine.

Conclusion

With so many new EVs in the market, the choice of what charging system to use can become an equally important and involved process. Arguably the most important factor when choosing what EV charger to purchase will be safety. The UL Listing Mark is the easiest and most clear way to identify if your new EV charger meets national safety standards with respect to design, performance, and installation. 

Especially since there are no legal requirements for manufacturers to sell UL certified products, it is important as a consumer to be aware of the nuances around UL ratings. A UL Listed product will feature a distinct UL Listed logo in addition to a serial number and product description. Surprisingly, many of the highly-rated EV charging stations sold on Amazon have not been tested at reputable third-party labs despite having great overall ratings. Besides that, deceptive logos that do not contain the exact elements pertaining to UL Listing status are key to watch out for. However thanks to the official UL Listing Mark, you can rest assured that you are getting a reputable product.

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