Ec In Motors

PCRA Training Programme on 06.11.2009

EC EC in in Motor Motorss By By Ashok. Ashok. S S PCRA PCRA Recour Recourse se per person son

PCRA Training Programme on 06.11.2009

These are the electric motors that consume the

most energy in the industry 9%

4%

Electrolysis Lighting Other uses

17%

Electric motors

70 PCRA Training Programme on 06.11.2009

The purchase cost of a motor

is nothing in relation to

its cost of use Purchase cost 2.5% Maintenance cost 1.5%

Energy cost

96

Global Cost of an electric motor PCRA Training Programme on 06.11.2009

Consumption Consumption of of electricity electricity by by Sector Sector

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Industrial Motor Energy Use Total 2.3 Quadrillion Btu/yr other 4%

material handling 12%

material processing 23% pumps 24%

refrigeration 7% compressed air 16%

fans 14%

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Motor Systems

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Energy Energy Efficient Efficient MotorsMotors- A A National National Priority Priority

70% of all electrical energy consumed in India is used for driving electric motors. 55% of which is consumed by industrial motors

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9

National National Standard Standard for for Energy Energy Efficient Efficient Motors Motors

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IS IS 12615: 12615: 2004 2004 (First (First revision) revision) -Superior -Superior to to existing existing Std. Std. IS IS 8789 8789 be considered as energy efficient, a motor must conform to one of the  To following efficiency levels specified in IS 12615:  

Improved Efficiency (eff 2) High Efficiency (eff 1)

 eff1 efficiency levels are higher than those of eff2. eff1 & eff2 are higher than the nominal values specified in IS 8789:  Both 1996.

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Range Range of of Energy Energy Efficient Efficient Motors Motors

 Eff 2 motors are offered ex-stock by few manufacturers. of manufacturers offer a complete range of eff 1 motors against specific orders with a  Most lead time of 8 to 10 weeks. Fast moving ratings are available of the shelf in case of Bharat Bijlee.

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Comparison Comparison of of efficiencies efficiencies of of Standard Standard & & Energy Energy Efficient Efficient Motors Motors Output 4 Pole

IS 8789

eff 2 as per IS 12615

eff 1 as per IS 12615

0.75 kW

71.0%

73.0%

82.5%

1.5 kW

76.0%

78.5%

85.0%

3.7 kW

83.0%

84.0%

88.3%

11 kW

85.5%

88.4%

91.0%

18.5kW

87.0%

90.0%

92.2%

37 kW

88.5%

92.0%

93.6%

75 kW

Not specified

93.6%

94.7%

110 kW

Not specified

94.4%

95.2%

160 kW

Not specified

95.0%

95.8%

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EFF1 EFF1 & & EFF2 EFF2 Motor Motor Load Load Vs Vs Efficiency Efficiency curve curve

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Salient Salient Features Features of of Eff1 Eff1 Motors Motors

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Why Why does does IS IS 12615 12615 specify specify two two efficiency efficiency levels? levels? User has the option to go for eff1 motor and save energy but at higher initial cost. It is strongly recommended to go for eff1 motor

 when utilization is high.

The standard is hence user friendly since it has provided two levels of efficiency. This is in line with other international standards

 like CEMEP.

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How How is is motor motor Efficiency Efficiency Improved Improved

Reduce (1)Iron Loss

Reduce (2)Copper Loss

Reduce Stator Cu Loss Reduce Flux Density Low Loss Magnetic matl.

Increase Copper Section

Stator slot area

Increase Stator Yoke Reduced

Reduce Rotor Diam Starting

Reduce Rotor Cu Loss Increase Rotor bar section Increased Starting current Torque

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Efficiency Efficiency improvement improvement to to eff1 eff1 by by use use of of Low Low Loss Loss Stamping Stamping & & increased increased Fe Fe and and Cu Cu

11 kW 1500 rpm

Iron losses PCRA Training Programme on 06.11.2009

Life Life Cycle Cycle Cost Cost of of Motor Motor



In one year, a motor consumes energy equivalent to 10 to 20 times its purchase price.



Many consumers in India especially OEMs purchase cheap motors having low efficiency values.

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Energy Energy Efficient Efficient Motors Motors have have aa Flat Flat Efficiency Efficiency Vs Vs Load Load Characteristic Characteristic

 Motor rating is selected for max. load conditions and next preferred rating  Most motors operate on an average around 75% load.

Efficiency is almost same from 60% to 100% load in a well designed EE motor

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Energy Energy savings savings increase increase at at partial partial loads loads due due to to Flat Flat efficiency efficiency vs vs Load Load Characteristic Characteristic

11kW-4 Pole eff 2 motor Vs eff1 motor.

Total Energy saving per annum : Rs. 12112 Additional Price of eff-1 motor over eff2 motor : Rs. 2627

Payback Period is 2.6 Months PCRA Training Programme on 06.11.2009

Eff1 Eff1 motor motor gives gives further further savings savings over over an an eff2 eff2 motor motor

Purchase Price of 11kW/4P motor Rs Efficiency

Eff2

Eff1

17509

20135

89.0%

Energy consumption p.a. for 8000 Hrs @ Rs 4 per kWH

3,95,504

91.5% 3,84,700

Energy Saving Rs

10804

Additional purchase price Rs

2626

Pay Back Period of eff1 motor is 2.9 months for a 15% price increase over eff2 motor PCRA Training Programme on 06.11.2009

Need Need for for High High Efficiency Efficiency Motors Motors



Use of High efficiency motors in sectors like Fertilizers / Sugar / Central Air-conditioning units and AHUs/etc, will allow considerable energy saving at locations with high usage.

 

The use of high efficiency motors helps to reduce the power consumption.



The following table will provide insights on energy savings on usage of energy efficient (eff-1) motors against (eff-2), or any other standard motor.



The ratings in the table correspond to the requirement of a modern building project, whose enquiry has come up with Bharat Bijlee

(Example in next slide)

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Rating

Efficiency

Qty of

Annual Savings

eff2

Motors

Rs.

eff1

Purchase Price (Approx) Rs.

Eff-2

Eff-1

Price

PayBack Period

HP

Pole

KW

1.5

4

1.1

78

83.8

1

1969.9

3755

4319

565

3.44

2

4

1.5

80

85

1

2205.9

4108

4721

613

3.34

3

4

2.2

82

86.4

1

2732.6

5427

6243

816

3.58

5

4

3.7

85

88.3

1

3253.6

6944

7990

1046

3.86

7.5

4

5.5

86

89.5

1

5001.9

9570

11008

1438

3.45

10

4

7.5

87

90.3

1

6300.8

11176

12857

1681

3.20

12.5

4

9.3

88

90.5

1

5838.8

17317

20048

2731

5.61

15

4

11

89

91.5

1

6753.9

17891

20573

2682

4.77

20

4

15

90.2

92.2

1

7214.6

22232

25568

3335

5.55

30

4

22

91.8

92.8

1

5164.9

33416

36756

3340

7.76

40

4

30

92

93.2

1

8397.1

45077

49586

4509

6.44

100

4

75

94

94.7

1

11795.4

123421

129594

6172

6.28

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Difference (Rs.)

Months

Replacement Replacement Vs Vs Rewinding Rewinding -11 -11 kW kW 44 pole pole motor motor Eff of Old Motor to be rewound or replaced

IS 8789

eff2

New motor Efficiency

eff2

eff1

Purchase Price of new motor Rs

16000

19200

Rewinding Cost Rs

4000

4600

Additional Cost Rs

12000

14600

Efficiency of old motor

85.5%

88.4%

Efficiency after rewinding ( less 1.5%)

83.0%

86.9%

Efficiency of new motor

88.4%

91.0%

Saving by replacement with new eff2 motor

0.809 kW

0.570 kW

For 5000 Hrs @ Rs 4.0 per kWH

16180

11406

8.9 Months

15.4 Months

Pay back period :

(Rs)

Replace old eff 2 motor with eff1 motor & get Payback in 15 months Replace old IS8789 motor with eff2 motor & get payback in 9 months PCRA Training Programme on 06.11.2009

Nameplates Nameplates -- Marking Marking of of Efficiency Efficiency

Manufacturer Name

3 ph. Induction motor

MADE IN INDIA

Type MH16M4734 Fr 160M

M/c. No

.

Volts 415 ∆ kW/HP 11/15

Hz 50

Insl Cl F

Duty S1 A

19.7

rpm 1460

Eff % 91.5 P f 0.85

EFF-1

Manufacturer Name

3 ph. Induction motor

MADE IN INDIA

Type MA16M433 Fr 160M M/c. No

.

∆ Volts 415 kW/HP 11/15

Hz 50

Insl. Cl F Duty S1

A 20.5

Eff % 89.0

rpm 1450

P f 0.84

EFF-2

A High Efficiency Motor

A Standard Motor (Improved Efficiency)

The EE motors are clearly labeled “EFF-1 or EFF-2” PCRA Training Programme on 06.11.2009

Inrush Inrush current current



Energy-efficient motors feature low electrical resistance and thus exhibit higher inrush currents than standard models. The inrush current duration is too short to trip thermal protection devices

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AdvantagesAdvantages- Apart Apart from from Higher Higher Efficiency Efficiency

•

Less maintenance and longer life time due to lower temperature in windings and bearings

•

Higher reliability due to lower losses.

•

Better tolerance to thermal stresses resulting from stalls or frequent starting.

•

Increased ability to handle overload conditions.

• 

Better resistance to abnormal operating conditions, such as under and over voltage or phase unbalance.

•

Higher tolerance to poorer voltage and current wave shapes.

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Design Design Factor Factor to to be be considered.. considered..

•

Motor Size. Size motors for efficiency. Motors should be sized to operate with a load factor between 65% and 100%.

•

The common practice of over sizing results in less efficient motor operation. For example, a motor operating at a 35% load is less efficient than a smaller motor that is matched to the same load

•

The Next figure explains the same.

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To To Add.. Add..



Energy savings are more at partial loads because Energy Efficient motors have a Flat Efficiency Vs. Load Characteristic



Payback period of eff2 motor over IS-8789 motor is approx 1500 working hrs.



Payback period of eff1 motor over eff2 motor is approx 2500 working hrs.

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How How to to Determine Determine Cost Cost effectiveness? effectiveness? The cost effectiveness of an energy-efficient motor in a specific situation depends on several factors, such as

      

Motor price Efficiency rating Annual hours of use Percent full load Energy rates Cost of installation and downtime, The availability of utility rebates or other incentives.

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Advantages Advantages of of Using Using High High Efficiency Efficiency Motors Motors

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When When Should Should II Consider Consider an an Energy-Efficient Energy-Efficient Motor? Motor?

Most motors should be replaced with an energy-efficient model if they operate over 1500 hours per year. In general, energy-efficient motors should be considered in the following circumstances:

 New installations, both separate and as part of packages such as HVAC systems  When major modifications are made to a facility or a process  Instead of rewinding old motors, use high-efficiency motors  Existing motors are under loaded or overloaded.  As part of a preventive maintenance or energy conservation plan

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Intermittent Intermittent duty duty applications….? applications….?



Intermittent duty motors are typically used in crane, hoist, valve actuators and other applications with frequent starts.



In these applications, motors are designed for low starting losses rather than low running losses.

For intermittent duty applications EE motors are not the best choice

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Problems Problems in in field field testing testing

 Efficiency measurement at site is unreliable.  

One needs to decouple the load in order to measure no load losses. Variable voltage supply required in order to maintain rated voltage.

recommend measurement of kWh using a energy meter and compare two  We motors. of current is not a reliable indicator. Current is not directly proportional  Measurement to input power because power factor varies with load and voltage.

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Who Who should should Help Help in in promoting promoting Eff1 Eff1 Motors? Motors?

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Energy Energy Efficient Efficient Motors Motors & & Carbon Carbon Credits Credits energy consumption means lesser burning of natural resources –  Lower Thus lower pollution.

 Better efficiency means lower operating costs, hence improved bottom lines. to participate in World Carbon Credit Market, which stands for  Opportunity just 6% in India (against 71% in China) at an estimated value of US $ 64 billion as per World Bank Estimate for 2007. (Source – Economic Times)

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Summary Summary & & Conclusion Conclusion



There exists a national standard IS 12615: 2004 (Revision 1) for energy efficient three phase induction motors from 0.37kW to 160 kW



Energy savings are more at partial loads because Energy Efficient motors have a Flat Efficiency Vs. Load Characteristic



Payback period of eff2 motor over IS-8789 motor is approx 1500 working hrs.



Payback period of eff1 motor over eff2 motor is approx 2500 working hrs.

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Thank you PCRA Training Programme on 06.11.2009