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This is a draft document and does not represent a definitive view of the agency on the questions 

addressed.

This and other guidance documents are accessible on the U.S. Department of Energy, Energy Efficiency 

& Renewable Energy web site at: http://www1.eere.energy.gov/guidance/default.aspx?pid=2&spid=1.

Guidance Type: Definitions and Scope of Coverage

Category: Residential Products

Product: External Power Supplies

Guidance Version: DRAFT

Issued: November 14, 2014

Comment Period Ends: December 15, 2014

The following is a draft U.S. Department of Energy (DOE or the Department) guidance document 

regarding the scope of the definition for external power supplies. This draft guidance document 

represents the Department’s interpretation of its existing regulations and is exempt from the notice and 

comment requirements of the Administrative Procedure Act. See 5 U.S.C. § 553(b)(A). Nonetheless, the 

Department is accepting comments and suggestions from the public until December 15, 2014. 

Comments and suggestions should be provided in WordPerfect, Microsoft Word, PDF, or text file format 

by sending an email to ExtPowerSupplies2014GUID0052@ee.doe.gov. Please also include the docket 

number http://www.regulations.gov/#!docketDetail;D=EERE-2014-BT-GUID-0052. 

Submitted comments are public and may be reviewed at Docket

http://www.regulations.gov/#!docketDetail;D=EERE-2014-BT-GUID-0052 on regulations.gov; if you wish 

to submit confidential business information as part of your comment, please contact DOE at the above 

email address. At the end of the comment period, this draft guidance document may be adopted, 

revised, or withdrawn.

Q: Are external power supplies that are packaged with and used to operate commercial or industrial 

equipment covered by the Department of Energy’s energy conservation standards?

A: The Energy Policy and Conservation Act of 1975, as amended (EPCA), defines an external power 

supply as an “external power supply circuit that is used to convert household electric current into DC 

current or lower‐voltage AC current to operate a consumer product.” 42 U.S.C. 6291(36). See also 10 

CFR 430.2. In a final rule issued on February 10, 2014, DOE discussed the applicability of the term 

"consumer product" in the context of the external power supply definition. See 79 Fed. Reg. 7846, 7860 

(Feb. 10, 2014). Despite this explanation, DOE continues to receive numerous inquiries about whether 

external power supplies packaged with and used to operate specific products or equipment need to 

meet DOE’s energy conservation standards. In response to these questions, DOE is issuing this draft 

guidance.

Consistent with EPCA and DOE’s regulations, any external power supply that is of a type capable of 

operating a consumer product would be considered a covered product and possibly subject to DOE’s 

energy conservation standards, without regard to whether that external power supply was in fact 

distributed in U.S. commerce to operate a consumer product. Only external power supplies that have 

identifiable design characteristics that would make them incapable of operating a consumer product 

would be considered to not meet EPCA’s definition of external power supply. 
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To be clear, while any device that meets the definition of an external power supply would be considered 

a covered product, DOE has only established energy conservation standards for certain types of external 

power supplies. Currently, external power supplies that meet the definition of a “Class A” external 

power supply are required to meet specific energy conservation standards articulated at 10. C.F.R.

§ 430.32(w)(1)(i). Beginning in 2016, direct operation external power supplies are also required to meet

energy conservation standards articulated at 10. C.F.R. § 430.32(w)(1)(ii). These new standards cover 

additional external power supplies that may have not previously been required to meet standards and 

also increase the stringency of the standards for many types of external power supplies that had 

previously been required to meet the Class A standards. More information on the current and future 

external power supply energy conservation standards is available on the DOE’s External Power Supply

website.