### Federal Register /Vol. 64, No. 120 /Wednesday, June 23, 1999 /Proposed Rules 33431

annuitant must repay any allotments paid after the date annuity payments should have ceased. (2) If annuity payments are made after the annuitant's death, OPM will recover from- (i) His or her estate; or, (ii) In an appropriate case, from any survivor benefits payable based on the annuitant's service; or (iii) If there is neither an estate nor a survivor annuity payable, from the allottee. (I) Allotments, except allotments to large organizations under agreements established prior to the effective date of these regulations, may only be made to a valid electronic-funds-transfer address established under part 210 of title 31, Code of Federal Regulations.

[FR Doc. 99-15686 Filed 6-22-99; 8:45 am]

BILLING CODE 6325-012-P



### DEPARTMENT OF ENERGY

Office of Energy Efficiency and Renewable Energy

10 CFR Part 432
[Docket Number EE-TP-98-550]


### Energy Conservation Program: Test Procedures for Distribution Transformers

AGENCY : Office of Energy Efficiency and Renewable Energy, DOE. 

### ACTION : Notice of availability of documents and limited reopening of the record and opportunity for public

comment 

### regarding the proposed rule and this Department of Energy (DOE or the reopening notice no later than July 23, Department) proposed in a Notice of 1999. Proposed Rulemaking ("NOPR" or ADDRESSES : Please submit 10 copies (no "Notice") to adopt a new regulation, 10 faxes) to: Kathi Epping, U.S. Department CFR Part 432. 63 FR 63360 (November of Energy, Office of Energy Efficiency 12, 1998). The regulation (the "proposed and Renewable Energy, "Energy Conservation Program: Test Procedures for Distribution Transformers, Docket No. EE-RM-S-97-700", EE-43, 1000 Independence Avenue, SW, Washington, DC 20585-0121. In addition, the Department requests that an electronic copy (31/2" diskette) of the comments on WordPerfectTM 6.1 be provided. Pursuant to the provisions of 10 CFR 1004.11, any person submitting information which he or she believes to be confidential and exempt by law from public disclosure should submit one complete copy of the document and ten (10) copies, if possible, from which the information believed to be confidential has been deleted. The Department of Energy will make its own determination with regard to the confidential status of the information and treat it according to its determination. Copies of the National Electrical Manufacturers Association Standard TP 2-1998, "Guide for Determining Energy Efficiencies for Distribution Transformers" (NEMA TP 2), the National Institute of Standards and Technology Technical Note 1427, "An Analysis of Efficiency Testing under the Energy Policy and Conservation Act: A Case Study with Application to Distribution Transformers" (NIST TN 1427), and other correspondence related 

### to this rulemaking are available for

SUMMARY : The Department of Energy previously published a Notice of Proposed Rulemaking to adopt test procedures for measuring the energy efficiency of distribution transformers under the Energy Policy and Conservation Act, as amended, 42 U.S.C. 6317(a). Since the time that Notice appeared, the Department has received documents and comments containing new information concerning National Electrical Manufacturers Association (NEMA) TP 2, the sampling plan, and transformers to be covered by the rulemaking. In addition, DOE has concerns regarding the definition of a basic model. The Department is reopening the record of its rulemaking to provide an opportunity for additional public comment on the validity of this new information and its implications regarding the proposed test procedures and the policy options now under consideration by the Department. DATES: The Department will accept comments, data, and information 

### public inspection and copying at the Freedom of Information Reading Room, U.S. Department of Energy, Forrestal Building, Room 1E-190, 1000 Independence Avenue, SW, Washington, DC 20585, (202) 586-3142, between the hours of 9:00 a.m. and 4:00 p.m., Monday through Friday, except Federal holidays.

FOR FURTHER INFORMATION CONTACT: Kathi Epping, U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, EE-43, 1000 Independence Avenue, S.W., Washington, D.C. 20585-0121, (202) 586-7425, email: Kathi.Epping@ee.doe.gov, or Edward Levy, Esq., U.S. Department of Energy, Office of General Counsel, GC-72, 1000 Independence Avenue, S.W., Washington, D.C. 20585, (202) 586- 9507, email: Edward.Levy@hq.doe.gov SUPPLEMENTARY INFORMATION : Pursuant to section 346(a) of the Energy Policy and Conservation Act, as amended (EPCA), 42 U.S.C. 6317(a), the 

### rule") would include test procedures for measuring the energy efficiency of distribution transformers; several definitions regarding the test procedure, including the definition of a distribution
transformer and the definition of a basic model; and a sampling plan for minimizing test burden. DOE held a public hearing on January 6, 1999, and received 9 written comments on the proposed rule. After reviewing the hearing transcript and comments, DOE concluded that a number of significant issues had been raised that required additional analysis. These issues include: (1) the adequacy of stakeholder opportunity to review NEMA TP 2; (2) the suitability of NEMA TP 2 to be adopted as the DOE test procedure; (3) transformers covered under the definition of "distribution transformer"; (4) the appropriateness of proposed sampling plans for demonstrating compliance; and (5) the suitability of the definition of "basic model" for the purpose of grouping transformers to limit test burden.

1. Availability of Documents
In the Notice, DOE stated it was proposing incorporation by reference either ANSI/IEEE standards C57.12.90 and C57.12.91 or NEMA standard TP 2. In the Notice, the Department stated its concern over whether TP 2 had undergone broad-based scrutiny, and DOE stated that, in order to accept TP 2, DOE would need sufficient evidence that all users and stakeholders have had an opportunity to review TP 2. In comments on the proposed rule, some stakeholders expressed concern that they had not been given the opportunity to Review NEMA TP 2. (ERMCO, No. 13 at 1; Dynapower, No. 17 at 1; and Howard Industries, No. 18 at 2.) 1 Because the DOE wants to ensure that all stakeholders have an opportunity to review TP 2, the Department has sent copies of NEMA TP 2 to the parties on its Distribution Transformer Stakeholder mailing list. In addition, the National Institute of Standards and Technology (NIST) issued Technical Note 1427 entitled "An Analysis of Efficiency Testing under the Energy Policy and Conservation Act: A Case Study with

I Comments are identified by company name, followed by comment number in the docket at page number. For example, "ERMCO, No. 13 at 1" means comment number 13, submitted by ERMCO, at page 1. Also note that comment number "11 DD" refers to the hearing transcript.

### 33432 Federal Register /Vol. 64, No. 120 /Wednesday, June 23, 1999 /Proposed Rules

Application to Distribution Transformers." (NIST TN 1427) The Department has also sent this report, which analyzes the sampling plans contained in proposed 10 CFR Part 432 and in NEMA TP 2 and compares them to each other, to the parties on the Department's distribution transformer mailing list. Copies of both NIST TN 1427 and NEMA TP 2 are available for inspection in the DOE Freedom of Information Reading Room. For information and copies of NEMA TP 2, please contact Anthony Balducci of NEMA at (703) 841-3245. For copies or questions on NIST TN 1427, please contact Ken Stricklett of NIST at (301) 975-3955.

2. NEMA TP 2 On the subject of whether NEMA TP 2 is ready to be adopted as the national test procedure, the American Council for an Energy Efficient Economy (ACEEE) has indicated its support of NEMA TP 2, provided that both NEMA and non-NEMA industry representatives have had sufficient opportunity to review the standard, and there is wide support for it among these representatives. (ACEEE, No. 20 at 1.) ACEEE and Dynapower, Inc. both expressed concerns, however, that NEMA TP 2 may not be appropriate for all customers. For example, the loading conditions may not be representative of all applications. For these reasons, Dynapower believes further evaluation is necessary before the final rule is issued, and ACEEE suggested that DOE investigate whether a corollary test procedure to address those transformers that distribute power to industrial or large commercial customers may be necessary in addition to NEMA TP 2. (Dynapower, No. 17 at 1 and ACEEE, No. 20 at 1.) Howard Industries believes having all the requirements in a single standard is NEMA TP 2's predominant advantage, and therefore Howard Industries tentatively supported the adoption of NEMA TP 2, pending a more thorough review. (Howard Industries, No. 18 at 1.) At the January hearing, ERMCO stated that it could not comment on NEMA TP 2 at that time, but that it did support the American National Standards Institute (ANSI) approval process. (ERMCO, No. 11 DD at 18-23.) At the same hearing, Edison Electric Institute (EEI) indicated its preference for ANSI standards. (EEI, No. 11 DD at 31.) In its comments on the NOPR, NEMA indicated that NEMA TP 2 has been submitted to ANSI's accreditation standards committee C57 for approval. NEMA further stated that it anticipated receiving ballots by the end of March 1999 and resolution of comments shortly thereafter, and that it should take approximately sixty days for ANSI to approve NEMA TP 2. (NEMA, No. 21 at 2.) Because of the controversy over the two options delineated in the proposed rule, the Department invites further comment on whether DOE should choose Option 1 (ANSI/IEEE standards C57.12.90 and C57.12.91) or Option 2 (NEMA TP 2), as described in the NOPR, for the final rule for test procedures. The Department also seeks comment on the subsidiary issue of the appropriateness of tying adoption of NEMA TP 2 to ANSI approval. In addition, the Department wants to ensure that the test procedures that DOE adopts are suitable for all distribution transformers that are being regulated under the statute. Because DOE is concerned that the loading factor in the test procedure may not be appropriate for all distribution transformers, DOE would consider the adoption of different loading factors for different types of distribution transformers in order to capture the loadings they typically carry and more accurately rate the efficiency level of each. DOE solicits comments on whether this course of action is appropriate. If several loading factors are selected, only the loading factors used in the calculations would change; the test procedure would remain the same. DOE realizes that, in developing the TP 2 loading factors, NEMA considered this issue, and the Department welcomes its comments as well as those of stakeholders not represented by NEMA.

3. Definition of Distribution Transformer

Section 346 of EPCA directs the Department to address the development of energy efficiency requirements for "distribution transformers." The statute provides no definition for "distribution transformer." As part of the Notice, the Department proposed a definition, so as to delineate the transformers that EPCA requires to be evaluated for standards and, therefore, initially subject to the test procedures. The definition in the proposed rule is as follows: "a transformer with a primary voltage of 480 V to 35 kV, a secondary voltage of 120 V to 600 V, a frequency of 55-65 Hz, and a capacityof either 10 kVA to 2500 kVA for liquidimmersed transformers or 0.25 kVA to 2500 kVA for dry-type transformers, except for (1) converter and rectifier transformers with more than two windings per phase, and (2) transformers which are not designed to be continuously connected to a power 

### distribution system as a distribution transformer. This second exception includes regulating transformers, machine tool transformers, welding transformers, grounding transformers, testing transformers, and other transformers which are not designed to transfer electrical energy from a primary distribution circuit, to a secondary distribution circuit, or within a secondary distribution circuit, or to a consumer's service circuit." 63 FR at 63370. The following are a list of areas of the definition in which there is disagreement among stakeholders: a. Low Voltage Transformers

In oral, as well as written, comments on the proposed rule, NEMA stated that the definition of "distribution transformer" in the proposed rule was too broad and should not include low voltage (600 Volts and below) transformers. (NEMA, No. 21 at 2 and No. 11 DD at 63.) In NEMA's view, these low voltage transformers are considered "general purpose transformers," which NEMA says are defined as "specialty transformers," not "distribution transformers." NEMA quoted the ANSI/ IEEE C57.12.80 definition of "distribution transformer" as "a transformer for transferring electrical energy from a primary distribution circuit to a secondary distribution circuit or consumer's service circuit. NOTE: Distribution transformers are usually rated in the order of 5-500 kVA." NEMA also noted that the IEEE Dictionary defines "primary distribution circuit" as "an alternating current circuit that supplies the primary of a distribution transformer from a generator, a substation, or a distribution bus." NEMA stated further that the IEEE Power Engineering Society does not consider low voltage transformers to be distribution transformers. However, NEMA acknowledged that in IEEE standard 241, the Industry Application Society (IAS) defines low voltage transformers as indoor distribution transformers, but went on to observe that the IAS consists of transformer installers, not manufacturers. (NEMA, No. 21 at 2-4.) Naval Facilities Engineering Command Atlantic Division (NAVFAC LANTDIV) indicated support of NEMA's comments regarding low voltage transformers. (NAVFAC LANTDIV, No. 22 at 1.) 

### Howard Industries commented that it suspects the definition of distribution transformer in the NOPR is too broad and suggested DOE perform a further review. (Howard Industries, No. 18 at 2- 3.)

### Federal Register /Vol. 64, No. 120/Wednesday, June 23, 1999 /Proposed Rules 33433

Tony Dell' arciprete, an Electrical Engineer for Electrical Design and Construction Projects for GSA, stated that indoor distribution transformers are distribution transformers. He also sited ANSI/IEEE Standard 241 the Gray Book "). He stated that he considers a 480 volt primary and a 120 /208 volt secondary to be a distribution level voltage

. Furthermore, he indicated that excluding these transformers by calling them " general purpose transformers" or "specialty transformers " is a "play on words ." (Dell'arciprete, No. 23 at 1.) In its comments on the proposed rule, ACEEE noted that ANSI/IEEE Standard 241 defines " indoor distribution transformer " as one for which "both primaries and secondaries are 600 volts and below (the most common ratio is 480-208Y/120V)," and that these transformers offer the greatest potential energy savings

. ACEEE also recommended that, given the ambiguity of the definition of the term "distribution transformer," the Department should " err on the side of a broader interpretation

- particularly at this stage of the process

, before standard setting has begun

- to ensure energy savings opportunities are not lost." (ACEEE, No. 20 at 2.) The Department is inclined to agree with ACEEE. Furthermore, the Department does not believe the definition of "distribution transformer" found in ANSI/IEEE standard C57.12.80 precludes the coverage of low voltage transformers

. The Department believes an alternating current circuit that supplies the primary of a distribution transformer from a 277/480 volt distribution bus would fall within the definition of "primary distribution circuit" that NEMA provided from the IEEE dictionary. Consequently, the Department believes that these low voltages are covered under the ANSI/ IEEE definition of "distribution transformers." The Department also is inclined to disagree with NEMA ' s interpretation that because low voltage and "indoor distribution transformers " are also referred to as " general purpose transformers" or "specialty transformers ," they are not distribution transformers

. In fact

, next to the terms "general purpose transformers" and "specialty transformers" in the IEEE dictionary are the words "(power and distribution transformers)." The Department believes these words indicate that the authors of the dictionary consider these transformers to be a subset of distribution transformers. Hence, it appears to the Department that the "indoor distribution transformers " defined in ANSI/IEEE standard 241, are merely a subset of " distribution transformers." The Department questions NEMA's implication that the Industry Application Society (IAS) IEEE standard is less valid because the IAS consists of installers of transformers, not manufacturers. In addition

, several manufacturers

, including Acme ElectricCorporation, Jefferson Electric, CutlerHammer

, Falvo Electrical Supply, and PowerSmiths International Corporation, identified these low voltage transformers as "distribution transformers" in their product literature/web pages

. Web pages for Delta Transformer and Hammond Manufacturing Transformer Group used the words " General Purpose Transformers (distribution)" and "General purpose distribution transformers ," respectively

, indicating that the terms " general purpose transformer " and "distribution transformer " are not exclusive . (Product literature , No. 24.) In the proposed rule's definition of distribution transformer

, as well as in the notice announcing its determination as to the distribution transformers for which standards appear to be warranted

, 62 FR 54809 (October 27, 1997), (" Determination Notice"), the Department construed the term "distribution transformer " in EPCA as including low voltage transformers. The Department does not find persuasive the comments discussed above that advocate a contrary approach

. Thus, the Department intends to adopt, in the final rule

, the proposed rule's inclusion of low voltage transformers in the definition of distribution transformer, unless it receives information that justifies exclusion of these transformers.

b. Capacity/

Power Ratings

NEMA commented that units with fractional power ratings are not defined as distribution transformers

, and NEMA recommended a capacity (power rating) limit of 15 kVA for dry-type distribution transformers . NEMA also provided a comment noting that ANSI C57.12.50 identifies a range of 1-500 kVA for drytype distribution transformers . (NEMA, No. 21 at 4.) The Department is inclined to agree with NEMA regarding fractional power ratings . Consequently, DOE does not intend to include transformers with kVA ratings less than one in the distribution transformer definition and intends in the final rule to increase the proposed rule's 0.25 kVA lower capacity limit for distribution transformers. However, the Department is undecided as to whether this limit for dry-type distribution transformers should be 1 kVA (consistent with ANSI C57.12.50), 5 kVA (consistent with ANSI C57.12.80), 10 kVA (consistent with the lower limit for liquid

- filled transformers ), or 15 kVA ( consistent with NEMA TP 2). The Department requests further comments on the appropriate lower limit for the power ratings of distribution transformers.

c. Liquid

-

filled Distribution Transformers
Edison Electric Institute (EEI) requested that liquid

- filled transformers be excluded from the rulemaking, because the utility market already drives these transformers to be efficient

, within the limits of cost effectiveness. EEI stated that utilities already apply total owning cost methodologies in its purchasing decisions

, and, therefore, it is unnecessary and counterproductive for the Department to mandate energy efficiency standards for liquid-filled transformers. However

, EEI conceded that it would not object to DOE compiling and comparing test methods approved by standards setting bodies such as IEEE and ANSI. EEI also voiced support for the EPA's voluntary Energy Star program . (EEI, No

. 19 at 1-5.) In the Determination Notice, the Department concluded that standards are warranted for liquid-filled distribution transformers. 62 FR 54816. Thus, they were included in the proposed rule. Because the final rule addresses test procedures only, and not whether efficiency standards are warranted

, the Department intends to include liquid

- filled transformers as outlined in the proposed rule. During the efficiency standards rulemaking, the Department will reevaluate its determination of the transformers for which standards are warranted. 62 FR 54817.

d. Rectifier and Converter Transformers
NEMA, Mr. Kline, and Howard Industries stated their belief that rectifier and converter transformers are not distribution transformers. (Kline, No. 14 at 1-2; Howard Industries, No. 18 at 3 ; and NEMA, No. 15 at 1-2 and No. 21 at 4-5.) As a result of these comments and discussion at the public hearing

, the Department is inclined to exclude from the "distribution transformer " definition all rectifier and converter transformers if they are built and labeled as such.

e. Autotransformers and Transformers with Tap Ranges Greater Than 15%

NEMA and Howard Industries requested that transformers with tap ranges greater than 15 percent and autotransformers be excluded from the

### 33434 Federal Register /Vol. 64, No. 120 /Wednesday, June 23, 1999 /Proposed Rules

rulemaking. (Howard Industries, No. 18 at 3 and NEMA, No. 15 at 2 and No. 21 at 5.) The Department is inclined to believe few of these transformers exist in the distribution system, little energy would be saved by regulating them, and excluding them would be unlikely to create loopholes in the regulation. Consequently, the Department is inclined to exclude these transformers from this rulemaking. 

### f Sealed/Non-Ventilated Transformers and Special Impedance and Harmonic Transformers

NEMA and Howard Industries requested that sealed/non-ventilated transformers and special impedance and harmonic transformers be excluded from the rulemaking. (Howard Industries, No. 18 at 3 and NEMA, No. 15 at 2 and No. 21 at 5.) However, NEMA's justification for their exclusion is the inability of these transformers to meet the TP 1 efficiency levels. NEMA provided no other reasons why these transformers should not be covered by the test procedure. These transformers were included in the proposed rule's definition of distribution transformer, 63 FR 63370, as well as in the Determination Notice, 62 FR 54811. The Department does not find persuasive the comments discussed above that advocate exclusion of these products. Thus, the Department intends to include sealed/non-ventilated transformers and special impedance and harmonic transformers in the test procedures final rule, unless it receives information that justifies exclusion of these transformers from the test procedures. The appropriate efficiency levels, if any, for these and other classes of distribution transformers will be evaluated during the efficiency standards rulemaking. 

### g. Retrofit Transformers

NEMA and Howard Industries indicated that while they do not recommend excluding all retrofit transformers, some currently operating transformers fit tightly into their locations or enclosures, making it impossible to replace them with more efficient transformers, which are generally larger or configured differently. (NEMA, No. 21 at 5 and Howard Industries, No. 18 at 3.) The Department is contemplating whether this situation calls for exclusion of these transformers from this rulemaking or for consideration of a separate class in a future standards rulemaking. In either case, the Department needs further information in order to define and treat these transformers appropriately. The Department is therefore soliciting further comments on how to distinguish these from other transformers and on the dimensional restrictions imposed on them. 

### 4. Sampling Plans In the NOPR, the Department proposed a methodology-a sampling plan-that a manufacturer would be required to use to establish the efficiency of a basic model of distribution transformers based on tests of sample units of that basic model. 63 FR at 63366-67, 63371. In its comments on the proposed rule, Howard Industries expressed concern that a large amount of testing and record-keeping may add unnecessary costs to its products. The company believes that the statistical approaches used in 10 CFR Part 430, upon which the proposed rule was based, are suitable for highly standardized products, while distribution transformers are very specialized products often produced in very low volumes. Howard Industries stated that certain sizes may be produced in quantities of less than five per year, and some may not even be produced at all for a whole year. The company strongly recommended that the approach adopted by DOE minimize the number of units that must be tested to satisfy both compliance and enforcement, and it suggested that basic models of which fewer than 5 units are produced in a 180 day period be exempt from the rule for this period of time and no testing be performed. Howard Industries believes the impact of energy loss due to this small quantity of units is so small it can be neglected. The company also supports the eight percent tolerance used in the NEMA sampling plan. (Howard Industries, No. 18 at 4.) Southern Transformer Company commented that it will be difficult for small companies to assemble, calibrate, and certify test sets to comply with the proposed rule's testing requirements. Southern Transformer Company suggested that DOE provide a grant to NIST to assist small companies in this effort. (Southern Transformer, No. 12 at 1.)In its comments on the proposed rule, NEMA urged the Department to use the sampling plan for compliance found in Section 7 of NEMA TP 2. (NEMA, No. 11 DD at 174, No. 15 at 3-4; and No. 21 at 6-8.) NEMA also stated that the 8 percent loss tolerance (throw-away limit) in the TP 2 sampling plan compels manufacturers to design their products to at least the minimum average efficiency standard. NEMA also stated that it would consider adopting, in Section 7 of NEMA TP 2, subdivisions of its globalized 

### aggregation into the following possible categories: Low Voltage Dry, Medium Voltage Dry, Liquid-Filled 500 kVA and below, and Liquid-Filled above 500 kVA. (NEMA, No. 21 at 7.) ACEEE supports a sampling plan that minimizes the testing burden, provided that a small sample can provide a high degree of confidence that efficiency levels reported by manufacturers are accurate. ACEEE believes the burden of proof is on the industry to prove NEMA TP 2 satisfies these conditions. ACEEE believes the sampling plan in the NOPR is satisfactory. (ACEEE, No. 20 at 3.) The Department still has concerns regarding the aggregation of basic models used in NEMA TP 2. Nonetheless, the Department recognizes the aggregation and 100% testing method in the NEMA TP 2 sampling plan does have merit, particularly for limited production models. However, the Department doubts that any basic models of which there are at least 50 units produced per 180 days would need to be aggregated with other basic models. The Department is inclined to believe that 100% testing of smaller, limited production models, coupled with the assurance that any individual unit that is 8% below a standard would be eliminated, renders it likely that these units would be designed to meet any applicable minimum standard efficiency. For the final rule, the Department, however, is considering adoption of one or some combination of the following sampling plan options: (1) Variation on NEMA TP 2: (a) Basic models for which all units are tested because the manufacturer chooses to do so, because of customer's specifications, requirements to comply with other standards, or other such reasons: 2 • Demonstrate the compliance of aggregations of basic models to theaggregate standard as described in TP2 Section 7.2.1. • Additionally, demonstrate the compliance of each basic model for which 50 or more units have been manufactured during 180 calendar days. 

### • Discard all units whose losses exceed 8% of the rated value for that basic model, as required by TP 2.

2For basic models that have sufficiently large numbers of units to minimize the statistical likelihood of error, this approach provides evidence, based on direct measurements, that each basic model meets or exceeds the efficiency standard. For basic models with limited production (< 50 per 180 days), the aggregation of both large and small production models reduces the risk of rejecting the limited production models due to the relatively high statistical possibility of erroneously estimating the mean of a population from a small sample.

### Federal Register /Vol. 64, No. 120/Wednesday, June 23, 1999 / Proposed Rules

(b) Basic models which consist of units of identical design and are tested on a sampling basis: • Per NEMA TP 2 Section 7.2.2, take a sample of at least five units of each basic model per month over a 180 calendar day period and compute from the test results the estimated mean of each basic model from the sample. • Demonstrate the compliance of the aggregate as in TP 2. • Additionally, demonstrate the compliance of each basic model for which 50 or more units have been manufactured during 180 calendar days. 

### • Discard all units whose losses exceed 8% of the rated value for the basic model as required by TP 2. For small population basic models of fewer than 5 units, all units must be tested. 

### (2) A sampling plan similar to that in the NOPR, allowing some form of aggregation for small production basic models. (3) The requirement of a certification of compliance or compliance statement only, in which the manufacturer would provide a written explanation of how it has demonstrated, verified, and certified compliance. In the written material accompanying the certificate, the manufacturer must demonstrate the basic premise for compliance. A sampling plan would be included in the final test procedures rule primarily for the purpose of demonstrating compliance with possible future standards. The Department acknowledges that a sampling plan is not necessary for the test procedure itself. However, the sampling plan might be used in the evaluation of possible future standards. The Department also recognizes that although some of the sampling plans under consideration may be adequate to demonstrate compliance with a minimum efficiency standard, these plans may not be adequate to address the question of efficiency representations. The Department is deliberating over whether labeling of particular efficiency values is appropriate for this product. The issue of representations will need to be addressed at a future time.

5. Definition of "Basic Model"
ERMCO, Howard industries, ACEEE, and NEMA supported the definition of "basic model" in the proposed rule. (ERMCO, No. 13 at 2; Howard Industries, No. 18 at 3; ACEEE, No. 20 at 2-3; and NEMA, No. 21 at 6.) ACEEE also suggested that industry sources provide guidance for ensuring manufacturers do not intentionally design some high efficiency models to counterbalance other low efficiency models within the same basic model. (ACEEE, No. 20 at 2-3.) 

### After further examination, the Department believes the definition of basic model in the proposed rule may be problematic. As set forth in the NOPR, a basic model is intended to be a group of models, produced by a given manufacturer, that have performance, design, mechanical, functional, and electrical characteristics that are essentially identical, and do not have refinements that affect energy consumption. 63 FR 63365. The general Part 430 definition of basic model was modified for distribution transformers in the proposed rule (Part 432). 63 FR at 63365-66, 63369. However, the proposed Part 432 definition of basic model may need some further modification. All products within the same basic model should be in the same product class. (In its standards rulemakings, the Department establishes a separate "class" with its own efficiency standard for a product when the record indicates that the product includes a utility or performance-related feature that affects energy efficiency.) The following is an example depicting how the proposed basic model definition may be problematic: A special impedance distribution transformer model, because of its inherently inferior efficiency, would likely be in a class separate from regular distribution transformers. The proposed basic model definition specifies that the following characteristics must be used to group different models of distribution transformers in a basic model: output power rating, voltage range, insulation type, and number of phases. These features of a special impedance distribution transformer, however, could be the same as for a regular distribution transformer. Consequently, under the proposed definition of basic model, these two transformers could be within the same basic model even though they would have significantly different efficiencies. This example illustrates that the current definition of basic model will likely categorize, within the same basic model, transformers that should be in different classes. The Department would appreciate comments on how the Department should deal with this problem. The Department realizes that manufacturers would prefer special classes of distribution transformers to be exempted from regulation. However, as previously stated, the Department does not find that solution to be appropriate in this test procedures rulemaking. 

### 33435

In grouping transformers into basic models, we have to look at all the features, and the ones that have widely differing effects on efficiency should not be grouped together. In the final rule, the Department is considering adding some other features that affect efficiency (such as physical material of the windings and core, physical size, and impedance range) to the definition of basic model. The Department is open to suggestions as to what other features should be considered for the basic model definition, so that we do not have the problem outlined above. The Department also is considering adding the words "and the other features of which have comparable effect on efficiency" to the proposed definition of "basic model" to alleviate this problem.

Issued in Washington, D.C., on June 17, 1999. Dan W. Reicher, Assistant Secretary, Energy Efficiency and Renewable Energy.

[FR Doc. 99-16020 Filed 6-22-99; 8:45 am]

BILLING CODE 6450-01-P

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NE

-26-AD]

RIN 2120-AA64

Airworthiness Directives; Rolls-Royce plc Tay 620

- 15, Tay 650-15, and Tay 651-54 Series Turbofan Engines

AGENCY : Federal Aviation Administration, DOT. 

### ACTION : Notice of proposed rulemaking (NPRM).

SUMMARY : This document proposes the adoption of a new airworthiness directive (AD) that is applicable to Rolls-Royce plc Tay 620-15, Tay 650- 15, and Tay 651-54 series turbofan engines. This proposal would require initial and repetitive visual inspections of the emergency fuel shutoff cable for broken strands or failed cables, and, if necessary, replacement with serviceable parts. This proposal is prompted by reports of broken strands and failed emergency fuel shutoff cables. The actions specified by the proposed AD are intended to prevent emergency fuel shutoff cable failure, which could result in the non-operation of the emergency fuel shut-off system in the event of a low pressure shaft failure.

DATES : Comments must be received by August 23, 1999.