The New Proposed Standards On Motor Efficiencies

The efficiency of a motor is determined when it is designed and manufactureddesigned and manufactured

Brian Fletcherbfletcher@baldor.com

Motor Summit, Zurich Switzerland 10 April 2007

Lifetime Cost of an Electric Motor

• Purchase price represents 2% of motor life cost

• One Rewind represents 0.7% of cost

• Electricity costs accounts 97%

How is Motor Efficiency Measured?

• Efficiency equals output divided by input

• Efficiency is expressed as a percentage

• Super-E efficiencies as high as 96%

Upgrading one 0.75 kW Eff2 motor to a Premium Efficient motor will eliminate every year:

1 Drum of Oil from being burned

240 Kg of coal from being burned

Up to 640 Kg of carbon emissions from being released into the atmosphere

and....

or....

The New Proposed Standards

• For a number of years now there has been one main standard in Europe also this standard is used in most of the world with the exception of the United State and Canada

• IEC 600034-2 this defines the standards of efficiency for 3 phase electric motors in the beginning the range was form 1.1 kW to 90 kW and only 2 and 4 pole and foot mounted

• The agreement by CEMEP (European Committee of Manufacturers of Electrical Machines and Power Electronics) . Adopted a voluntary agreement with Electric motor manufactures to have 3 standards EFF3, EFF2 and EFF1.

The New Proposed Standards

• Eff3 is the lowest efficiency and over the years this has slowly started to disappear and only a few OEMs now use the type of motor.

• EFF2 is still the majority on the motors sold in Europe with some 80% plus of motor sales mainly to OEMs.

• EFF1 this being the highest efficiency motor as a standard in European now accounts for some wear in the region of 12% of motor sold this in the main is to end users.

The New Proposed Standards

• In the United States they have 2 standards for electric motors:

– EPAct ( The Energy Policy Act) and – Nema Premium motors (There is one other standard

which is IEE 841).• Epact motors are mandatory in the United States and are

the equivalent to our EFF1 but at this time we have no equivalent to Nema Premium motor.

• In 2006 Australia and New Zealand adopted new standard MEPS (this is the same as IEC 61972).

The New Proposed Standards

• The main difference between IEC 60034-2 and IEC 61972 in the first standards set it was agreed the stray losses would be the same for all kilowatt powers.

• In IEC 61972 the stray losses are defined by kilowatt power from 0.75 kW through to 200 kW and this is more in line the United States standards.

• The main difference between the United States methods of measuring efficiency and the methods used in Europe is that in the United States they measure the power in and the power out.

How Is Motor Efficiency Measured?

Efficiency test method “IEEE 112 method B” is most accurate and is mandated by EPAct and NEMA

Dynamometer tested

Segregated loss determination

Stray load loss measurement

Conservative but accurate

Specified by NEMA MG1-12.54 & EPAct

Never forget to compare efficiency published with knowing the method used to define efficiency.

The New Proposed Standards

• The IEC (International Electro-technical Commission) are proposing new standards on efficiency of electric motors. This is the IEC Project 60034-30 by TC2 working Group 31.

• There Strategic Goals are: 1. Classes for single-speed three-phase cage induction

motors in stationary application2. Support High and Premium Efficiency motors3. To Ensure the rules are precise, consistent, reasonable and

practical worldwide.4. To get as much acceptance by user, manufactures and

national legislation bodies as possible.5. To concentrate regulation on those motor size and models

which have the widest distribution.6. To Harmonize worldwide standards on efficiency classes

(both 50Hz & 60Hz)

The New Proposed Standards

• To this aim the working group have proposed 3 new standards: – 1-Star(*)equivalent to EFF2. – 2-Star (**) equivalent to EFF1 and – 3-Star (***) which is a new standards and will be equivalent

to Nema Premium motors • The method of testing that is proposed is Eh-Star, reason why:

– In a large number of tests by both The University of Nottingham and the University of Darmstadt which started in August 2003 and the project closed in June 2005.

– In all 130 different test where carried our on a range of motor from1.1 kW to 110 kW,

• The test method where– IEC 60034-2, IEEE 112-B, IEC 61972, Reverse Rotation

IEEE 112-E, Calorimetric IEC 60034-2A and Eh-Star.

The New Proposed Standards

The following conclusion were made:• Eh-Star test do not appear to give stray load loss much

different form IEC 61972.• Eh-Star test are much simpler and quicker that IEC 61972

and no Mechanical connection to a dynamometer of load machine are needed.

• The Eh-Star method is simple and well suited for the determination of stray load losses in manufacturers test bay without coupling to machine or dynamometer.

The New Proposed Standards

• In conclusion it is proposed that this working group will strive to have a new World Wide standard accepted by most countries in the world by the end of 2008 as a voluntary code and that a number of countries will make it Mandatory with in 2 years.

• The leading light in this progression will be Australia and New Zealand, China, India and we hope that European countries will also follow.

Comparison of defined efficiency

75

80

85

90

95

100

1.1

2.2

5.5 11

18.5 30 45 75 110

187

250

340

Power kW

EPActNEMA PremiumEFF2EFF1

Stray lossesMotor Power

kW IEC 60034-2future

IEC 619720.75 0.50 3.001.1 0.50 2.991.5 0.50 2.992.2 0.50 2.983.7 0.50 2.975.5 0.50 2.967.5 0.50 2.9411 0.50 2.9215 0.50 2.89

18.5 0.50 2.8622 0.50 2.8430 0.50 2.7837 0.50 2.7245 0.50 2.6655 0.50 2.5875 0.50 2.4495 0.50 2.30110 0.50 2.16150 0.50 1.88

Assumed stray load losses (% of full-load power)

Stray load losses are due to Magnetic transfer loss in the air gap between the stator and rotor

Actual publications are based on IEC 60034-2

Stray losses are measured by method IEEE 112B (NEMA EPAct & Premium)

Comparing published Efficiencies same motorMotor Power

kW IEEE112B IEC 34-2 JEC-37

0.75 76.8 78.8 79.61.5 81.1 83.1 83.82.2 81.4 83.4 84.13.7 83.9 85.9 86.55.5 84.8 86.8 87.37.5 85.6 87.6 88.111 87.4 89.4 89.915 88.3 90.3 90.7

18.5 88.9 90.4 90.822 89.8 91.3 91.730 90.4 91.9 92.337 91 92 92.445 91.5 92.5 92.855 92 93 93.375 92 93 93.395 92.2 92.7 93110 92.8 93.3 93.6150 93.8 94.3 94.6

Motor Efficiency published

• IEEE 112B: Measure Power in / Power out

• IEC 60034-2:Estimate 0.5% for stray losses

• IEC 61972:Estimate stray losses ref to power

• JEC 37:Japan - ignores stray losses altogether

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Number of polesPNkW

2 4 6

0,75 72,1 72,1 70,9

1,1 75,1 75,1 73,5

1,5 77,2 77,2 75,6

2,2 79,7 79,7 78,0

3 81,5 81,5 79,9

4 83,1 83,1 81,5

5,5 84,7 84,7 83,2

7,5 86,1 86,1 84,7

11 87,6 87,6 86,5

15 88,7 88,7 87,8

18,5 89,4 89,4 88,6

22 89,9 89,9 89,3

30 90,8 90,8 90,3

37 91,3 91,3 90,9

45 91,7 91,7 91,5

55 92,2 92,2 92,0

75 92,7 92,7 92,7

90 93,0 93,0 93,0

110 93,3 93,3 93,3

132 93,6 93,6 93,6

160 93,8 93,8 93,8

200 and above 94,0 94,0 94,0

Table 1ANominal values (%) for standard efficiency (*) for 50 Hz

Number of poles

2 4 6

A 0,45892 0,45892 -0,16546

B -4,82747 -4,82747 -2,54321

C 17,23496 17,23496 15,90237

D 74,35952 74,35952 72,88859

Table 1BInterpolation coefficients for standard efficiency (*) for 50 Hz

Table 2ANominal values (%) for standard efficiency (*) for 60 Hz

Number of polesPNkW

2 4 6

0,75 74,7 74,4 73,8

1,1 77,3 77,1 76,2

1,5 79,2 79,1 78,0

2,2 81,3 81,4 80,2

3,7 83,9 84,1 82,9

5,5 85,6 85,9 84,8

7,5 86,8 87,1 86,2

11 88,2 88,5 87,8

15 89,2 89,5 89,0

18,5 89,8 90,1 89,7

22 90,2 90,6 90,2

30 91,0 91,4 91,2

37 91,5 91,8 91,7

45 91,9 92,3 92,2

55 92,2 92,6 92,7

75 92,8 93,2 93,3

90 93,0 93,5 93,6

110 93,3 93,8 93,9

150 93,7 94,2 94,2

185 and above 93,9 94,5 94,4

Table 2BInterpolation coefficients for standard efficiency (*) for 60 Hz

Number of poles

2 4 6

A 0,37759 0,54538 -0,12297

B -4,09586 -4,77248 -2,38117

C 14,94559 15,96001 14,33244

D 76,64929 76,44834 75,59345

Table 3A Nominal values (%) for high efficiency (**) for 50 Hz

Number of polesPNkW

2 4 6

0,75 79,5 81,1 76,1

1,1 81,2 82,7 78,3

1,5 82,5 83,9 79,9

2,2 84,1 85,2 81,9

3 85,3 86,3 83,4

4 86,3 87,3 84,7

5,5 87,4 88,2 86,0

7,5 88,4 89,1 87,3

11 89,6 90,2 88,7

15 90,5 90,9 89,7

18,5 91,0 91,4 90,4

22 91,4 91,8 90,9

30 92,2 92,5 91,7

37 92,6 92,9 92,2

45 93,0 93,2 92,7

55 93,4 93,5 93,1

75 93,9 94,0 93,7

90 94,2 94,3 94,0

110 94,4 94,5 94,3

132 94,7 94,7 94,6

160 94,9 94,9 94,8

200 and above 95,1 95,1 95,0

Table 3BInterpolation coefficients for high efficiency (**) for 50 Hz

Number of poles

2 4 6

A -0,02693 -0,04477 -0,00090

B -1,69718 -1,45102 -2,37862

C 10,27411 9,12957 12,99176

D 80,77610 82,28980 77,72490

Table 4ANominal values (%) for high efficiency (**) for 60 Hz

Number of polesPNkW

2 4 6

0,75 81,5 82,8 78,6

1,1 83,0 84,2 80,6

1,5 84,1 85,3 82,0

2,2 85,4 86,5 83,8

3,7 87,1 88,1 85,9

5,5 88,3 89,2 87,5

7,5 89,1 90,0 88,5

11 90,1 90,9 89,8

15 90,9 91,6 90,7

18,5 91,4 92,1 91,3

22 91,7 92,4 91,7

30 92,4 93,0 92,5

37 92,8 93,3 92,9

45 93,1 93,7 93,3

55 93,5 94,0 93,7

75 93,9 94,4 94,2

90 94,2 94,6 94,5

110 94,4 94,8 94,8

150 94,8 95,1 95,1

185 and above 95,0 95,3 95,3

Table 4BInterpolation coefficients for high efficiency (**) for 60 Hz Number of poles

2 4 6

A -0,07060 -0,04671 0,00913

B -1,20109 -1,26283 -2,14037

C 8,52479 8,13483 11,53721

D 82,62796 83,87689 80,07918

Table 5ANominal values (%) of efficiency for premium efficiency (***) for 50 Hz

Number of polesPNkW

2 4 6

0,75 82,4 83,8 79,2

1,1 83,9 85,2 81,2

1,5 85,1 86,2 82,7

2,2 86,4 87,4 84,4

3 87,4 88,3 85,7

4 88,3 89,1 86,9

5,5 89,3 89,9 88,1

7,5 90,1 90,7 89,1

11 91,1 91,6 90,4

15 91,8 92,3 91,2

18,5 92,3 92,7 91,8

22 92,7 93,0 92,3

30 93,3 93,6 93,0

37 93,7 93,9 93,4

45 94,0 94,2 93,8

55 94,3 94,5 94,2

75 94,8 94,9 94,7

90 95,0 95,1 94,9

110 95,3 95,3 95,2

132 95,5 95,5 95,4

160 95,7 95,7 95,6

200 and above 95,9 95,9 95,8

Table 5BInterpolation coefficients for premium efficiency (***) for 50 Hz

Number of poles

2 4 6

A 0,01742 0,01590 0,06053

B -1,56280 -1,39050 -2,36076

C 8,86182 7,91092 11,68063

D 83,55841 84,84846 80,67875

Table 6ANominal values (%) of efficiency for premium efficiency (***) for 60 Hz

Number of polesPNkW

2 4 6

0,75 84,3 85,4 81,5

1,1 85,5 86,5 83,2

1,5 86,4 87,4 84,5

2,2 87,6 88,5 86,1

3,7 89,0 89,8 88,0

5,5 90,0 90,8 89,3

7,5 90,7 91,5 90,2

11 91,6 92,2 91,3

15 92,2 92,8 92,1

18,5 92,6 93,2 92,6

22 92,9 93,5 93,0

30 93,5 94,0 93,6

37 93,8 94,3 94,0

45 94,1 94,6 94,4

55 94,4 94,8 94,7

75 94,8 95,2 95,1

90 95,0 95,4 95,4

110 95,3 95,6 95,6

150 95,6 95,9 95,9

185 and above 95,8 96,1 96,1

Table 6BInterpolation coefficients for premium efficiency (***) for 60 Hz

Number of poles

2 4 6

A -0,0269 0,0077 0,0566

B -1,0996 -1,1998 -2,0845

C 7,2914 7,0077 10,2926

D 85,1915 86,2446 82,7900

ENERGY SAVING…

Electricity is an Electricity is an expense you expense you mustmust control!control!