Listed External Power Supply = also known as wall-wart, cord & brick, direct plug-in transformer, etc.

If your product is powered by a UL Listed power supply, do you need to get the overall product UL
Listed? Unfortunately, this question cannot be answered with a simple yes/no. Should it be Listed?
Probably, especially if you don’t want to find out the hard way that you should have had it Listed. But,
only you can decide if it “must” be Listed. Consider the following:
- Hazards Remain: Just because the power supply is UL Listed doesn’t mean that there are no
safety requirements that apply to your product. Certainly there are fewer requirements that are
applicable, but there are issues to address; products powered by Listed power supplies can still
be a hazard. That is especially true if the power supply is used to recharge a lithium battery –
lithium batteries have inherent hazards that must be addressed with each application. - The Right Choice: Not just any UL Listed power supply is acceptable for your application. Be sure
you choose the proper power supply = UL certifies power supplies for many different applications
including “ITE power supply”, “Medical power supply”, “LED Lighting driver”, or “Hair clipping &
shaving power supply”. Besides the intended application, power supply output classifications can
also affect the requirements on your product. For example, some applications require a power
supply with a “SELV” output rating. You may also want to consider using a power supply certified
with a “Class 2” output rating which provides the most benefit (towards reducing the requirements
on the product powered by the power supply). - Consequences: If you do not get your product Listed, will anybody “reject” its use in the field?
Nothing is worse than having your customer be told they can’t use your product because it’s not
“Listed”. For example, U.S. Federal Law requires all products used in the workplace be “Listed”. - Benefits: The manufacturer has ultimate liability in the US. If you are subject to a product liability
concern, you are in a much more defendable position if the product itself is Listed.
The choice is yours – but hazards do exist – do you want to take the risk?
CertifiGroup operates a complete product Test & Certification Laboratory
CertifiGroup also has experts available to assist you with all your compliance needs