Distribution Transformers

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As defined in the Code of Federal Regulations (CFR), “distribution transformer” means a transformer that (1) has an input voltage of 34.5 kV or less; (2) has an output voltage of 600 V or less; (3) is rated for operation at a frequency of 60 Hz; and (4) has a capacity of 10 kVA to 2500 kVA for liquid-immersed units and 15 kVA to 2500 kVA for dry-type units. The term “distribution transformer” does not include a transformer that is an: autotransformer; drive (isolation) transformer; grounding transformer; machine-tool (control) transformer; nonventilated transformer; rectifier transformer; regulating transformer; sealed transformer; special-impedance transformer; testing transformer; transformer with tap range of 20 percent or more; uninterruptible power supply transformer; or welding transformer.10 CFR 431.192

Manufacturers have been required to comply with the U.S. Department of Energy (DOE) energy conservation standards for distribution transformers since 2007.

Current Standard | Current Test Procedure | Ongoing Rulemaking for Standards | Ongoing Rulemaking for Test Procedure | Helpful Links


Recent and Ongoing Activities

For the latest information on the planned timing of future DOE regulatory milestones, see the current Office of Management and Budget Unified Agenda of Regulatory and Deregulatory Actions. All planned dates are preliminary and subject to change.

Standards

DOE published a final rule prescribing new energy conservation standards for distribution transformers. 78 FR 23335 (April 18, 2013).   

The liquid-immersed and medium-voltage dry-type distribution transformers energy conservation standard rulemaking docket EERE–2010–BT–STD–0048 contains all notices, public comments, public meeting transcripts, and supporting documents pertaining to this rulemaking.

The low-voltage dry-type distribution transformers energy conservation standard rulemaking docket EERE–2011–BT–STD–0051 contains all notices, public comments, public meeting transcripts, and supporting documents pertaining to this rulemaking.

Public Meeting Information:

There is no public meeting scheduled at this time. 

Submitting Public Comments

The comment period is closed.

Test Procedure

DOE has published a notice initiating a data collection process through a Request for Information to consider whether to amend DOE’s test procedure for distribution transformers. 82 FR 44347

The docket EERE-2017-BT-TP-0055 contains all notices, public comments, and supporting documents pertaining to this rulemaking.

RELATED DOCUMENTS

Request for Information

  • Request for Information, Federal Register82 FR 44347 (September 22, 2017).
  • Request for Information, Request for Information; re-opening of public comment period, Federal Register, 82 FR 50324 (October 31, 2017). 
  • Comment deadline: Closed

Public Meeting Information

There is no public meeting scheduled at this time.

Submitting Public Comments

Comment period is closed.


Current Standard

Distribution transformers manufactured and distributed in commerce, as defined by 42 U.S.C. 6291(16), must meet the energy conservation standards specified in the Code of Federal Regulations at 10 CFR 431.196.


Current Test Procedure

To determine that distribution transformers that are currently manufactured or distributed into commerce are in compliance with DOE standards, manufacturers must follow the test procedure methods specified at 10 CFR 431.193 and Appendix A.


Helpful Links

Compliance

DOE has established regulations on certification, compliance, and enforcement in the CFR at 10 CFR Part 429.  These regulations cover statistical sampling plans, certified ratings, certification reports, record retention, and enforcement.  More information on these regulations is available here.

Waivers

For information on current test procedure waivers, see DOE’s Waivers webpage

For information about obtaining test procedure waivers, see 10 CFR 430.27.

Exceptions

DOE's Office of Hearings and Appeals has not authorized exception relief for distribution transformers.

For information about obtaining exception relief, see 10 CFR part 1003.

Guidance and Frequently Asked Questions

For information on further guidance and answers to Frequently Asked Questions on all covered products, see DOE’s Further Guidance database

State Exemptions to Federal Pre-emption

DOE has not exempted any state from this energy conservation standard. States may petition DOE to exempt a state regulation from preemption by the Federal energy conservation standard. States may also petition DOE to withdraw such exemptions. For details, see 10 CFR part 431, subpart V or subpart W.

Contact information

For more information related to this product, please email:
ApplianceStandardsQuestions@ee.doe.gov


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