tal P Jw-fLhi I /”

I 1 How will the Energy Policy Akt2L?PIpaf T affect electric motors?

The new U.S. law goes way beyond what NEMA ever called for, mandating that efficiency be verified through a thirdparty

By Richard L. Nailen, P.E., EA Contributing Editor HIS COUNTRY HAS NO ENERGY POLICY.” That was a common complaint five to ten years ago, as T the United States seemed to be settling back into a

complacent dependence on foreign oil. But it isn’t valid today. Like it or not, we do indeed have such a policy-the 1992

Energy Policy Act, or EPACT. (For an outline of the provisions concerning electric motor efficiency, see Electri- cal Apparatus, May 1993, “The Energy Policy Act: What does it really say about electric motors?’).

Right now, the legislation is approaching its second birthday. As far as the motor market is concerned, how is it working out? Well, some things that were expected to happen by now have not taken place. Other developments are not quite as expected.

As most of us know by now, EPACT requires certain standard “general-purpose’’ polyphase motors manufactured after October 1997 to meet specific full-load efficiencies. One authority recently estimated that 40 percent of the motor market will be affected; others feel that figure is too low. (The law’s efficiency values were first “suggested for future de- sign’’ four years ago in the standards of the National Electrical Manufacturers Association.) The law also requires motors to be labeled with nominal efficiency values. That, too, has been in NEMA MG 1 for years.

A third provision of the law, however, goes significantly

Figure 3 (Above). An example of a motor testfacility. Dynamometer test beds in this laboratory are equipped to accurately check eficiency of standard motors up to several hundred horsepower.

30

beyond what NEMA MG1, as a voluntary trade association document, has ever called for. The law mandates that the labeled efficiency be verified through a third party-some agency that is neither manufacturer nor purchaser.

There are two reasons for this. One, of course, is that EPACT is law, and a law implies enforcement. Enforcement requires evidence of compliance.

A second reason is consumer protection-providing as- surance that buyers can rely on sellers’ claims. From the beginnings of NEMA nameplate efficiency markings, motor purchasers have been concerned about the accuracy of those values. Nameplate efficiency forms the only basis for economic justification of the investment in a premium-priced product. (Even when such a product is required by law, machines of even higher efficiency will always be available, and promnted as an additional energy-saving meaure.)

Nameplate values After it’s explained to them, users can grasp the concepts

of test tolerance and manufacturing variation (see Figure 1). But once those unavoidable differences have been accounted for in arriving at nominal and minimum motor efficiencies, the user looks for assurance that the nameplate value truly reflects that result. Who hasn’t heard some rumor that one motor supplier or another has been padding the figures to make themselves look good in a competitive market?

Are motor manufacturers cheating? Are they fudging the efficiency values being marked on their nameplates? The subject is naturally a sensitive one. Don’t expect to see any published data from any source. But we can say this much

ELECTRlCALAPPARATUS I SEPTEMBER 1994

-All photos, unless otherwise credited, by Richard L. Nailen and copyright 1994 by Barks Publications, Inc

4&dwF+tareas, replacement offailed motors and obsolete pumps has resulied in more conven- tional assemblies such as ihese 40 hp, 3600 rpm drives.

daily to permit hot water cleaning of the interior of all pipes, valves, fittings, etc. The system had to include numerous joints that could easily be disconnected, then put back together after cleaning-a procedure involving literally miles of piping.

The diagram on the bottom right side of page 26 illustrates such a “hand takedown” or COP (Clean Out of Place) method for one simple process. A COP procedure has several drawbacks be- sides the constraints on piping construc- tion. It’s highly labor intensive. Waste water from the cleaning process must be disposed of. Frequent handling of separable parts risks damage.

A CIP installation adds up-front in- vestment, but eliminates those disad- vantages. The diagram shows how it works. Cleaning solution introduced from the system rinses out the entire line, then can be recirculated. Solution temperature is controllable. But there is more equipment-including pumps- needing both electrical and mechanical maintenance.

Because the CIP system is so much faster and easier, Golden Cheese needs only four or five daytime hours to clean up the plant, allowing production to go on unintempted throughout the rest of the day. Explained Kammarmeyer, “Normally we go ‘on milk‘ at 7 a.m. The milk comes into the unrefrigerated silos, where we keep track of its temperature. Production starts by noon. During the morning we can do all our maintenance while the sanitizing is going on.”

The importance of process continuity leads to the question: What if the neigh- boring cogen facility is down? Golden Cheese still has its own boiler plant. If DESTEC’s electrical output is unavail- able, the cheese factory can revert to all-utility supply, because that feeder circuit was put in place before the cogen plant was built.

In addition, the electrical intercon- nections between the two properties are arranged to permit Golden Cheese to

Cascade of cleanser foam surrounds floor-mounted pump/motor assembly during daily plant sanitizing. Most motors must be “washdown duty” design to withstand such treatment.

power up DESTEC’s auxiliaries for “black plant” startup. tem filters.

An 85 kilowatt diesel generator gives Golden Cheese a final backup. If all other power is lost, the stirring ap- paratus in the 11 cheese vats can still operate, so cheese in process will not “set up” into an unrecoverable mass. Also operable from the genset are water pumps for backflushing in the whey

department, to avoid plugging the sys-

With so much publicity about urban sprawl, freeways, aerospace, and semi- conductors, we may easily forget that California’s economy retains a strong food industry base derived from inten- sive agriculture, and making use of the newest technology. The Golden Cheese Co. operation reminds us of that. W

Milk silos Cheddar Block

- Weigh

Incoming milk

seal maturing

lnaB Weighing

Table I Vacuum Cheese

& To feed supplement storage

evaporation

Cream Butter-

Whey butter

storage

Pasteur. Whey storage WPC

+4 Feed Ethanol supplement 4f

Feed supplement

Flow diagram of just two of the five production lines indicates complexity of the Golden Cheese plant operation. Most wastewater is either evaporated or purijied and demineralized for cleaning or boiler use.

ELECTRICAL APPARATUS I SEPTEMBER 1994 29

(and remember-as yet, no legal penalties apply for any motor failing to meeting the nominal efficiency on its

Several hundred motors have been efficiency-tested in two independent North American laboratories that use the NEMMEEE (Institute of Electrical and Electronic En- gineers) test methods with what is conceded to be authorita- tively accurate results.

An extremely small percentage of those motors have tested below nameplate efficiency.

A still smaller percentage failed to meet the minimum efficiency associated (by NEMA standards) with the nameplate nominal value.

Various actions have been taken to find, and correct, the cause of such discrepancies. In a few instances, the motor involved was shipped back to the factory for further study.

Among the possible conclusions from such investigations are:

We don’t fully know how efficiency of a broad range of motors is predictably affected by quality control limits and manufacturing process variations. How important is the tightening of a particular tolerance or the control of a par- ticular process? We’re not entirely sure.

No matter what the standard spread may be between “nominal” and “minimum” efficiencies, the relationship is based upon statistical probability (again, see Figure 1). There will always be some likelihood, however small, of an in- dividual motor failing to meet the standard spread.

*Manufacturers in general are being honest and are cooperative in seeking to minimize discrepancies-insofar as the state of their knowledge will permit.

Two options Two options were available in drafting EPACT’ s provision

for verification. One choice was to mandate periodic third- party testing of selected motors as the units came off manufacturer’s production lines.

That method poses two problems. The first is that of arriving at a sampling rate mutually agreeable to all parties. Testing only a single motor per year would yield no statistical assurance of honest efficiency labeling. Testing every motor produced would be economically impossible. Where is the happy medium to best demonstrate manufacturer integrity at least cost?

The second problem is that even a low sampling rate for each of the dozen or more domestic suppliers alone would create a testing workload far beyond the capability of the available independent laboratories. Only one lab now exists in the U.S. that has been shown capable of sufficiently ac- curate work. Where will the equipment, the experience, and the expertise come from to suddenly staff half a dozen more !abs? And what abont dl the imported moters?

Therefore, NEMA recommended that EPACT be drafted around the second option: certifying or “qualifying” the ex- isting motor manufacturer test facilities as being sufficiently accurate. Here’s what the law says, in Section 122:

“With respect to any electric motor to which standards are applicable . . . the Secretary shall require manufacturers to certify, through an independent testing or certification pro- gram nationally recognized in the United States, that such motor meets the applicable.”

The intent of that language is that the “independent” pro- gram attest to the integrity of the manufacturer’s in-house testing. Motors need not be tested by any outside laboratory as proof of the manufacturer’s ongoing compliance with the law.

‘ name3late):

ELECTRICAL APPARATUS I SEPTEMBER 1994

Test tolerance (applied to (10% of nominal value)

‘c

higher

1 0% higher-

V f t Efficiency Mlnimum Nominal

Figure 1. Statistical distribution of eficiency values for all motors of a given design clusters around the “nominal” value as shown here. This expresses the manufacturing variations between individual motors. For all motors, a 10 percent tolerance on test results has been established by extensive NEMA studies.

Instead, an outside agency is expected to evaluate the manufacturer’s test facility and methods. Selection of that agency, and how the work will be done, is within the rulemak- ing authority of the Secretary of the Department of Energy.

The agency at least tentatively selected is NVLAP-the National Voluntary Laboratory Accreditation Program. An arm of the National Institute of Standards and Technology (NIST), NVLAP is certainly “nationally recognized” since its 1976 inception. It offers accreditation in many technologies, from testing carpeting to computer applications. As of 1993 NVLAP had accredited 879 laboratories, 3 4 of them for asbestos fiber analysis, nearly 80 in nuclear radiation dosimetry, and 72 doing construction materials testing.

On Sept. 16, 1993, NEMA’S Motor & Generator Section sent a letter to the Director of NIST, requesting that NIST set up a laboratory accreditation program for motor efficiency testing within the NVLAP structure. That letter was published on page 4037 of the Federal Register, January 28,1994, with explanatory material from the NIST pointing out that “The test methods for accreditation discussed at NEMA and DOE meetings . . . will be . . . IEEE Standard 112 Test Method B, and NEMA Standards Publication MG1-1987, as set forth in the EPACT legislation. . . .”

The purpose of that publication was to open a 60-day period for receipt of public comment on the proposal, after which the NET Directer weak! p~b!ish a Federd Register notice of the decision regarding development of the program. But no alternative choice was expected.

Motor efficiency testing is new to NVLAP. A procedure handbook for this work, drafted in June 1993, is still in the review process awaiting final publication. But the proposed accreditation process would include these features:

1. Basic authority: Federal regulations, 15 CFR 285 Ap- pendix A.

2. Procedures compatible with IS0 9000 quality manage- ment standards and several other pertinent IS0 documents, such as IS0 Guide 25 concerning laboratory evaluation.

3. Period of accreditation: one year, renewable; a published NVLAP fee schedule applies.

Please turn to next page

31

.~ - -

~

EPACT continued from preceding page 4.On-site facility and methods assessment by a “technical

expert with experience in the appropriate field of testing,” contracted for by NVLAP; visit to be repeated every two years.

5. “Proficiency testing.” This is defined as “the determina- tion of lab performance by means of comparing and evaluat- ing tests or calibration on the same or similar items of materials by two or more laboratories in accordance with predetermined conditions.”

6. Accreditation of overseas test labs (for imported motors) in the same way as in the US.

Item 4 contains several uncertainties that will have to be better defined as work gets under way. NVLAP was still seeking out expert “assessors” at the beginning of 1994. Who they would be was the subject of some speculation; retired engineers of long experience in product manufacturing and test, perhaps, although few such people are to be found. Many product designers today lack suitable background in test procedures.

Other agencies, visualizing a business opportunity, have begun offering “efficiency verification testing services.” Un- derwriters Laboratories (UL), seeking some “diversification” in its work scope, announced such a program late in 1993. Several universities in the West and Midwest have announced similar programs.

None of that, however, is being promoted or advocated by either the DOE or NEMA. Although

acquisition and processing equipment isn’t shown. Also not pictured is the specialized knowledge, painstakingly gathered experience, and tight process control that make the test ?esults ’

trustworthy. None of that comes either quickly or cheaply. Merely installing a dynamometer and some meters won’t suffice. Although UL’s testing and certification capability is well established for many types of electrical apparatus, motor performance testing is new to them. Academic laboratories are even less well-versed in the standards involved.

In addition, it’s unclear what would ever motivate a motor manufacturer having an in-house, government-certified test facility to spend the money and take the time to ship product elsewhere for testing. The UL program was to include an “efficiency mark” on each motor. That, too, would represent added cost to the manufacturer, similar to that for explosion- proof identification plates. State and local codes won’t re- quire such marking, because they are pre-empted by EPACT, which appears to be complied with by the existing system of nameplate marking.

~

NIST’s new role Incidentally, don’t dismiss the NIST as a coterie of fussy

scientists concerned only about whether or not a pound really weighs a pound. This quiet agency is getting an 80 percent budget hike this fall and expects another 50 percent boost by 1996. The NIST’s new role is to decide “which new tech- nologies the federal government should back.” Before his

election, President Clinton pledged to Y

UL has claimed to be “finalizing” their procedures and evaluating test results “with the assistance of the National Electrical Manufacturers Association,” NEMA does not, in fact, favor any such outside program. Said a spokesman for NEMA’S Task Force late last year, “It was the manufacturers’ intent [in re-

enhance NIST’s functionzandthat’s happening, with more facilities (half a billion dollars committed so far); new research programs; and heavy involve- ment in production/manufacturing technology. After years of puttering in the background of science, the NIST now seeks to put its stamp on public

One EPACT objective is assurance that buyers

can rely on claims

commending the test certification wording of EPACT] never to rely on a third party as a certifier of our product.” As far as both NEMA and the government are concerned, certification of the motor manufacturers’ own test facilities through NVLAP will be the recognized proce- dure for compliance with EPACT. See Figure 2.

Of course, the initial NVLAP samples will have to be tested elsewhere. That, however, will not be a major or ongoing task.

EPACT includes nominal efficiency limits for 1 13 ratings in the 1-200 hp 2-4-6 pole open and enclosed categories. Among those, NEMA proposes to pick the available models having the lowest efficiency (and therefore the highest losses) that still meet the law’s requirements, and from those choose five test samples, probably from the highest volume manufac- turers so that the design will be the most firmly established. ine exact sampiing procedure hasn’t been announced yei.

The biggest problem with outside testing is lack of ex- perience in the data collection and analysis needed to achieve the necessary test precision. Based on the history of the IEL (Industrial Electrotechnology Laboratory) motor test facility in Raleigh, N.C., and Hydro Quebec’s LTEE (Laboratoire des Technologies Electrochimiques et des Electrotechnologies) test lab in Shawinigan, Quebec, Canada (both of which took part in the latest NEMA round robin efficiency test program upon which the 1994 revision of NEMA MG1 is being based), an investment between $150,000 and $500,000 plus at least a year of experience is needed to do the job right.

Figure 3 shows the kind of test facility that’s needed. Although this laboratory is not large (1500 square feet is ample), and doesn’t appear particularly elaborate, the data

32

m.

policy. Insofar-as EPACT ‘section 122 is concerned, will the agency be content merely to oversee existing IEEE/NEMA test methods in someone else’s shop? Time will tell.

In Canada, verification of nameplate efficiency has always been stressed by utilities offering customer rebates for pur- chase of more efficient motors. Hundreds of motors have been tested by LTEE. However, national legislation in Canada, somewhat similar to EPACT, will take effect in 1996, supplanting earlier legal requirements within in- dividual provinces.

In view of that, the Canadian Standards Association (CSA) announced two years ago the undertaking of a national “ener- gy efficiency verification service” for motors. This had two objectives: (1) to see that products met legislated perfor- rriarice standads, a id (2) io veri€y that iimtors met whatever performance levels were claimed by manufacturers.

The program was to include CSA evaluation of the motor manufacturer’s production operations as well as testing of “representative samples,” followed by authorization to apply “controlled program marking” (analogous to a UL label) to qualified products at specified factories. Follow-up audits and periodic re-testing would maintain the qualification.

The sample testing could be carried out either at a CSA- approved “designated facility” or in the manufacturer’s own shop if that were approved. Testing would be in accordance with CSA Standard C390, expected to produce essentially the same results as from IEEE 1 12 Method B . One difference was that the “rated efficiency” tested in Canada and used as the basis for rebates, could be at either 100 percent or 75 percent

ELECTRICAL APPARATUS I SEPTEMBER 1994

load, the latter efficiency often being somewhat higher. Shoukd a sample motor fail on test to meet its claimed

cefficiency, a second sample of the design would be tested. Failure of that second motor to pass the test would result in the manufacturer being required to revise the rating informa- tion or have the product “de-listed” from the program. Peri- odic “cross-testing” (every three years) would compare results from manufacturer or outside lab tests for consistency with results at a CSA-designated facility.

All of this work would be paid for through fees charged the individual motor manufacturers. Also included would be possible “challenge testing.” A manufacturer, motor user, or some regulatory authority might apply to the CSA for a special test to check out a motor suspected of not meeting a performance requirement. The challenger would have to pay for the test. If the motor failed to pass, the challenger would be reimbursed. The motor manufacturer would be liable for payment, as well as for the re-testing and possible product de-lis ting .

However, as of early 1994, this ambitious program-far beyond what has been proposed in the U.S.-is not fully operational. The data gathering format, plans for monitoring manufacturer quality assurance, and a complete fee schedule had not been completed. But some testing had been done, and a few products had been found deficient (action was pending).

Small motors In the U.S., while the NIST/DOE/NEMA collaboration

works out the details of test verification for medium induction motors, the matter of “small” motors (below the 140 frame) remains unresolved. Section 124 of EPACT states in part:

“The Secretary shall within 30 months after the date of the enactment. . . [of EPACT] . . . provide testing requirements for those small electric motors for which the Secretary makes a determination that energy conservation standards are tech- nologically feasible and economically justified, and would result in significant energy savings.”

Three-phase units, generally U, 3/4, and 1 hp, would logi- cally be tested per the same IEEE Standard 112 method applicable to their larger three-phase counterparts. However, the NEMA round robin test programs of 1978-79 and 1993, which carefully established the range of variation to be ex- pected in both manufacturing and testing (again, see Figure 1) formed the only basis for the nameplate efficiency values that NEMA published (and that EPACT adopted in part). To be that reliable, the small motor test procedure needs to includes these features:

Data analysis that will properly deal with stray load loss and dynamometer error.

Proper adjustment for test temperature. Accurate sensing of motor shaft torque. Control of voltage magnitude, waveform, and (for tinree-

phase machines) phase balance. No such testing has been done for smaller machines. There-

fore, we have no proof that the same variations will apply as for larger motors. Inasmuch as unavoidable differences from one motor to the next will tend to become larger percentages as the motors become smaller, we may find that new ranges of variation will be needed for “small” motors. We just don’t know yet.

Unfortunately, below the 140 frame, most motors are not three-phase but single-phase. Efficiency testing for those is more complex. They are of several basic types-shaded-pole, universal, permanent split-capacitor, capacitor-start, etc. Even assuming that the identical test would apply equally well to all of those, the efficiency ranges that are reasonably

ELECTRICAL APPARATUS I SEPTEMBER 1994

I ! w 2 - I - I I Figure 2. Interrelationships through which motor manufacturers’ eficiency testing capability will probably be verified. ( I S 0 = International Standards Organization, which produces guidelines for laboratory evaluation; DOC and DOE are US. Departments of Commerce and Energy).

to be expected from “energy efficient” single-phase machines have not been documented or even determined. With medium three-phase motors, all that was well established before NEMA efficiency standards were published.

The only IEEE standard for single-phase performance testing, No. 114, lacks most of the sophisticated data analysis used with IEEE 112. Furthermore, it has lapsed, and was withdrawn by the IEEE in 1992.

How are we doing on the EPACT timetable for small motors? The law allows 30 months for rulemaking. By the spring of this year, more than half that time had passed without creation of any draft standard. Neither NEMA nor the IEEE has any interest in producing a standardized test proce- dure.

Some months ago, the DOE began exploring some of the issues involved in its Oak Ridge and Lawrence Laboratories. But neither of those agencies has experience in industrial motor application, design, manufacturing, or testing.

In Canada, a CSA subcommittee has been considering this matter. A proposed small motor efficiency test standard, No. C747, is now in its third draft. The 18-member group includes representatives from five utilities, several govemment agen- cies, and five small motor manufacturers (four of them in the U.S.). We cannot give details of the document here because it’s still under discussion. But some of the necessary features to place test results on a par with previous NEMA work still seem to be lacking.

Also under close scrutiny are EPACT’s exemptions for “definite-purpose’’ and “special-purpose’’ motors. Those cat- egories, defined in the law as they are by NEMA, are far from precise. Vertical P-base motors, for example, are considered definite-purpose-and properly so, because they cannot be used in normal horizontai foot-mounted applications. Most contain thrust bearings for high hydraulic loads. Those bear- ings will not even operate properly when the shaft is horizon- tal.

Electrically, though, such a motor will usually be identical to its horizontal-shaft counterpart. Windings, laminations, core stack-all will be the same. But for the vertical unit the stated efficiency is valid only without external thrust load. When that load is imposed, friction loss rises drastically, and efficiency drops accordingly.

That effect is so well-understood that MG1-12.09 contains a standard formula for evaluating the influence of thrust on bearing loss (provided the thrust bearing is a single angular- contact ball bearing). If that procedure has been acceptable

Please turn to next page

33

Figure 4. This line of general-purpose motors includes an optional C- flange bearing bracket that can be added for brake mounting or some pump applications. For vertical installation, the f rame f e e t can be removed.

-U.S. Electrical Motors photo

EPACT continued over the years for “standard efficien- cy” motors, today’s thinking is that it should be equally

acceptable for “energy efficient” machines. But no ruling has been made.

A more uncertain candidate for reconsideration is the C- flange option. Its most frequent usage is for the close-coupled pump assembly. Such a motor may include a special shaft extension-which in itself won’t influence efficiency. But because of the overhung weight of a pump impeller, the close-coupled machine may also use an oversize drive-end bearing. Because of the hazard of pump leakage directed right at that bearing, a special rubbing seal may be used at that end of the motor. Those options add loss. A decision must be made as to whether or not that will significantly change motor efficiency.

NEMA standards give a C-flange motor the suffix letter “C” in its catalog or nameplate frame designation. If a con- ventional general-purpose motor, not so designated, is con- verted in the field to a C-face mounting using parts such as shown in Figure 4, will the nameplate be marked to include that suffix letter? Not likely.

The vertical in-line pump contributes more confusion. As part of such an assembly, the motor is always vertical. The construction may be of the close-coupled type, in which the motor bearing must sustain vertical hydraulic thrust, and the motor shaft extension is special to suit the direct mounting of the pump impeller. Alternatively, the motor shaft may be standard, but a “rigid coupled” construction involves a separate coupling joining motor and pump shafts. Still a third option is the “flexible coupled” design in which a separate pump bearing sustains all the thrust load.

All these motors may use the same mounting flange. How- ever, only one of them will exhibit the same efficiency as the general-purpose horizontal motor. The simple term “close- coupled pump” construction is not a sufficient definition.

Definite-purpose motors Two other groups of “definite-purpose’’ motors seem likely

to be brought under EPACT jurisdiction before too long. Some question exists, though, as of whether this can be done by DOE “rulemaking,” or will require Congressional amend- ment of the legislation.

The first is the “ratioed” design for NEMA standard volt- ages other than 230 or 460. No technical reason bars a “200” volt or a “575” volt machine from using the same electrical parts, and offering the same efficiency, as the standard 230 or 460 volt design. Yet EPACT exempts those other voltage ratings.

A second group of exemptions under scrutiny includes NEMA Design C ratings. For motors 2 hp and below, NEMA standards never distinguished between Designs B and C. In larger sizes, up to the 200 hp limit of this design letter, NEMA

34

C motors are not high slip designs, and manufacturers now appear to agree that they should be able to provide NEMA C torques without any decrease in efficiency compared to’ Design B. Hence, NEMA C may be brought within EPACT.

What about the provision in Section 122 Part (d) of the law that allows a motor manufacturer to petition the DOE for exemption of a product that either won’t save enough energy to justify high efficiency, or can’t meet the law’s efficiency levels because of technology limitations? The law provided a specific time period for that exemption process.

However, a DOE spokesman confirmed in March 1994 that no such petitions had yet been received. Here’s the DOE’s position on this issue: Any motor that is “definite-purpose” or “special-purpose” is already exempt from the Act, auto- matically. If a motor is constructed such that technological limitations prevent its meeting the efficiency specified for a general-purpose machine, then the DOE considers that motor to fall within the definite- or special-purpose category. It’s built differently. It’s exempt without the need for any petition. On the other hand, for any motor constructed along general- purpose lines, such that it can meet the specified efficiency, the mere fact that it’s intended for a “special” application isn’t grounds for exemption by petition or otherwise.

Consider, for example, a fire pump motor. It doesn’t run at all, unless periodically tested, from one year to the next. Is its efficiency important to energy conservation? No. But there is no practical way to distinguish that 50 hp fire pump motor from any other standard, general-purpose 50 hp motor. Since the same motor could readily be used for a continuous-duty application as well as for the normally idle fire pump, it cannot be exempted from EPACT requirements. If, to handle the fire pump duty, the motor required special construction

considered either definite- or special-purpose, and thus would be exempt without petition.

The DOE spokesman conceded that “We’re on the edges here; it’s a hazy area.” The rules may change. But for now, exemptions are neither being sought nor granted, because NEMA shares the DOE’s view of the situation.

The EPACT exemption procedure specifically applies to a “type or class of electric motor developed on or before the date of enactment . . . .” Each petition for exemption must “include evidence that the type or class of motor meets the criteria for exemption.” Where does that leave motor “types or classes” developed after EPACT became law? The DOE will consider such cases when and if they arise.

Has EPACT attempted to define “minimum” efficiency, as well as nominal? No. There is talk of that happening. NEMA standards suggested in 1990 that for future designs the mini- mum efficiency should correspond to losses 10 percent greater than the nominal (the “standard” loss difference had been 20 percent).

That was based on the expectation that manufacturing and test process control improvements would permit tightening up the originally standard 20 percent loss difference. How- ever, further round robin testing during 1993-94 has con- firmed that the 20 percent figure needs to be retained, and NEMA is revising the suggested value to agree. The sig- nificance of that tolerance, and how it is related to manufac- turing variations from one motor to the next, is shown in Figure 1.

How the DOE may deal with all this, if anything, is unknown. No action has been taken yet. As the EPACT legislation continues to be fleshed out by rulemaking and amendment, we look forward to the law’s third birthday. Stay tuned. r

~

1

I I I features, then in all likelihood it would automatically be

I I

ELECTRlCALAPPARATUS / SEPTEMBER 1:

This is another in a monthly series of a-c control wiring diagrams being published in Electrical Apparatus. Future installments will feature more circuit diagrams, definitions, and tables of commonly used sym- bols. -Editor

Modified low-voltage control In this modification of low-voltage control, the control relay is used only to change a green light to red when the motor is running, or vice-versa; no universal standard applies.

Circuit to test lamp condition When a pilot lamp is used to indicate when a starterisenergized, an unlitlampmaymeaneither that the starter is de-energized or that the lamp has failed. In this circuit, a push-to-test button, which can be pari of the lamp assembly itseg allows a test of lamp condition.

Fused primary and secondary Here, both primary and secondary sides of the control transformer are fused. The motor starter is rated for the primary voltage (typically 480), whereas the remaining control devices are low- voltage.

35 ELECTRICAL APPARATUS I SEPTEMBER 1994

Electrical service down on the farm

On ancestral land surrounded by cornfields, a family-owned electrical service company takes root

By Kevin Jones, EA Senior Editor

AYLOR, TEXAS-On the open plains of central Texas, you adapt T or move on. It’s been that way for

years. The homesteaders who settled here a hundred years ago learned to switch commodities as quickly as the demands of the marketplace changed. Has the price of cotton gone up? Raise more cotton. Has the price of cotton gone down? Raise more corn. And if you can’t raise crops, fix machines.

Bennie Tomecek and his wife Bon- nie, owners of Tomecek Electric Motor Repair, are heirs to this tradition. In fact, Bor,n:e :s ar, heir ir, the !itera! ser,se, having inherited land a few miles out- side of Taylor that has been in her fami- ly since the nineteenth century. On this land, the Tomeceks operate a 5,000- square-foot electrical service shop and a 57-acre farm on which they raise corn, maize, cotton, and goats. Next to the shop they have built a comfortable ranch-style house with a satellite dish out front.

The key to their success is flexibility. Independent and diversified, their com- pany can pursue a new enterprise when another enterprise shows signs of flag-

36

. .

ging. Or, as Bennie puts it, “We just try to strive for quality that we can charge for,” regardless of the service provided.

From the ground up The Tomeceks started their business

in 1970, after Bennie had served an apprenticeship at Armco Steel in Hous- ton. Their first building, which is still standing, was no larger than a single-car garage. Bennie, who did all the winding himself back then, was limited to repair-

. . northeast of the state’s capital, Austin.

ing motors 30 hp and below. While put- ting up a larger, adjacent building, he taught Bonnie to rewind motors;and she * taught the first employees to wind motors as the company began hiring them a couple of years later.

After the first year in business, the company moved into its second build- ing, which is several times larger than the original. Bennie continued to add on to this building as the business grew. Now it is a rambling structure with entrances in unexpected places and numerous nooks and crannies where old drills, lathes, and other equipment sit tucked away under tarps.

Once a bustling shop, this building is now used mainly for storage. It houses used motors, customers’ motors, lift truck parts, antique tractors, and other odds and ends that the company ac- quires-sometimes intentionally, sometimes not-and that may be of some value in the future. In the office, to which Bennie retreats with customers to escape the distractions of the shop, is stored an eccentric array of com- modities, from a stock of discontinued bearings to vegetables from the garden.

The newest building, which was completed in 1991, forms a stark con- trast to the original building in size and to the second building in tidiness. It is a high-ceilinged, well-ventilated struc- ture with a IO-ton bridge crane with Ibfoot lift and three two-ton jib hoists. A large bay door on the south side of the building-which happens to be the building’s front-takes advantage of prevailing southerly winds. Everything in the shop appears to have been put where it is for a reason.

Do-it-yourselfer Bennie laid out the new building him-

self and acted as his own general con- tractor. His main supplier, who Bennie says acted more like an architect than a contractor, guided him through the design. He advised Bennie to plan the building on a grid before building any- L111LL6, uoll,B yo y’uybL Lv .,,reser,t machinery. “There wasn’t any waste- it worked real good,” says Bennie. “You can move paper easier than a big lathe.”

Bennie allowed the head machinist to lay out the machine shop in such a way that he’d be able to work several machines at once. Bennie also got the crane manufacturer involved in the building design. When the crane was delivered, “it didn’t take any time to drop it in place and bolt it in,” he says. When Bennie installed the wiring, he put in a circuit breaker larger than necessary and additional conduit in case

thinr. .line nf nOnnr trr ..an

ELECTRICAL APPARATUS I SEPTEMBER 199