ENERGY SAVINGSwith

MOTORMANAGEMENT

The Way Forward

A guide to assist the development of your ownMotor Management corporate policy

ABB Motors Ltd

January 1996

ENERGY SAVINGS

with MOTOR MANAGEMENT

The Way Forward

ABB Motors Limited

South Point

Sutton Court Road

Sutton

Surrey SM1 4TY

Tel. 0181 395 8585 Fax. 0181 395 8991

ABB Motors Limited 9 The Towers Wilmslow Road Didsbury Manchester M20 8RB

Tel. 0161445 5555 Fax. 0161448 1016

© Copyright ABB Motors Ltd 1996

All rights reserved. No part of this publication may be used, reproduced, stored in information retrieval systems or transmitted in any manner whatsoever without the express written permission of ABB Motors Ltd

The Way Forward

CONTENTS

1. Introduction

2. Why you need a Motor Policy

3. Purchasing new motors

3.1 General Specification

4. Upgrading existing plant

4.1 Ontario Hydro report

4.2 Replacement guide

4.3 Corporate Policy flow chart

5. Energy studies

6. Twenty questions and answers

ABB Motors

The Way Forward

1. Introduction

The Department of the Environment's Energy Efficiency Office estimates that electric motors account for 64% of industrial electrical demand within the U.K. The most common usage is to drive fans, pumps and compressors.

The number of industrial motors rated above 1.5kW in the UK, exceeds 8 million. About 1,500 new motors are purchased daily, most being standard induction motors rated below 300kW.

The electricity used by this 67GW motor population costs about £2,000 million annually, with a further £1,000 million consumed in commercial applications such as refrigeration, air conditioning and ventilation systems.

In an increasingly competitive world many companies are looking to reduce energy costs as part of their drive to reduce overheads. This has inevitably meant scrutinising areas of common practise which would not have been considered in the past.

One of these is the area of motor management where savings can be made by considering the impact on motor efficiency when purchasing new plant or considering repairing a failed motor. A motor management policy can achieve savings through:

• Reduced energy costs • Reduced downtime • Reduced stock inventory

This guide is designed to assist your company develop a practical motor management policy that will focus all disciplines within your company toward reducing energy costs and increasing overall competitiveness.

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2. Why You Need A Motor Policy

Many companies have diverse areas of responsibility which make decisions on the utilisation of motors. Each will follow practices that meet their individual demands, but these may not consider the issues of energy efficiency, which will bring benefits to the company as a whole.

By introducing a corporate motor management policy, clear directions and guidelines are given to all parties involved to make the correct commercial decision to take into account the savings available from Energy Efficient motors.

There are two defined areas which will be covered by the policy:-

l) New Investments To gain maximum benefit, the best time to fit Energy Efficient motors is at the start of the plant life cycle which will compound the overall savings. Section 3 describes a practical policy for this area.

2) Upgrading Existing Plant You can improve the efficiency of your existing plant by retrofitting Energy Efficient motors. Section 4 demonstrates how cost effective this can be.

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3. Purchasing new motors

Efficiency has a far greater effect on the overall cost of a motor compared to its capital cost. Even small increases in efficiency will make a substantial saving in the overall cost of a motor, taking into account its operating and capital cost.

For example, a 11kW motor costs, typically, under £500 to buy, yet over £50,000 to run over a 10 year operating life. The purchase price therefore, is just 1% of the motor's total life cycle cost.

The table below compares the capital cost of various motor sizes with their running costs by showing approximately how long it takes to consume their own capital cost in energy cost.

CAPITAL COST VERSUS RUNNING COST

Rating 5.5k\V 18.5kW 90kW 250kW Approximate capital cost £285 £680 £3,700 £10,500 Typical efficiency 85% 90% 92% 94% Input kW 6.47 20.56 97.83 265.96 Daily running cost £7.76 £24.67 £117.40 £319.15 Time to consume own cost 37 days 28 days 32 days 33 days Assuming continuous duty at a tariff of £0.05/kWh

To reap the maximum benefit of low running costs, the time to select energy efficient motors is when purchasing new plant.

The suppliers and manufacturers of new plant rarely consider energy efficiency as a benefit to themselves, but will purchase and fit energy efficient motors when specified to do so by their clients.

The following draft specification can be used to develop your company's motor specification and ensure you receive the benefits of energy efficient motors.

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3.1 General Specification

1. Scope

1.1 This specification covers the general requirements for AC Electric Low Voltage Motors rated 0.4kW - 630kW for general purposes excluding flameproof types.

2. Duty & Rating

2.1 All motors shall be suitable for use in an industrial plant where continuity of operation is of prime importance.

2.2 Motors shall be suitable for direct on line starting unless otherwise stated

2.3 Unless the application warrants other duties or ratings, motors shall have a Continuous Maximum Rating running duty SI in accordance with IEC 34.

2.4 Original Equipment Manufacturers shall ensure that for fixed speed drives the duty point absorbed power shall not be less than 75% of the Maximum Continuous Rating of the motor.

2.5 Motors for use with variable frequency converters or variable voltage controllers shall be rated accordingly and complete drives matched to ensure compatibility.

3. Voltage & Frequency

All motors shall be suitable for a 415V, 3 Phase, earthed neutral 50Hz supply of tolerances + 6% of voltage ± 1% of frequency or combination of both.

Design & Performance

4 1 All motors shall conform to all relevant parts of 1EC Publication 34 and other standards as applicable. Particular attention is drawn to:-

1E 72 (1971) DimensionsIE 34-5 (1981) Degree of Protection 1E 34-1 (1983) Ratings & Performance IE 34-14 (1982) Vibration IE 34-9 (1972) Noise Levels

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4.2 Efficiency

All motors shall be of the High Efficiency, Low Loss design and shall meet the minimum requirements shown in the attached Table A.

4.3 Thermal Protection

Built in thermal protection shall be provided for motors rated 30kW and above. A minimum of 3 PTC Thermistors shall be provided for each motor with 2 ends terminating in the terminal box clearly and permanently marked.

4.4 Noise Levels

Sound pressure level shall not exceed 83dB (A) at 1m on full load in accordance with IEC 34-9.

Enclosure

Motors shall be Totally Enclosed Fan Ventilated ICO141 to a standard of IP55 or better in accordance with IEC 34-6 and IEC 34-5.

Insulation and Winding

Motors shall have Class F insulation throughout with temperature rise limited to Class B (80°C) in accordance with IEC 85.

8.

Bearings

7.1 Bearings shall be heavy duty ball or roller type with facilities for relubrication on frames 160 and above.

7.2 Sealed for life bearings guaranteed for a minimum of 2 years shall be preferred for smaller motors.

Terminal Boxes

8.1 Terminal boxes shall be of metal construction with a facility to rotate in steps to accommodate other cable entry positions.

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8.2 Boxes shall be bonded to the main frame earth and the frame of each motor shall be provided with an earth terminal.

8.3 Terminal markings shall be in accordance with IEC 34-8.

8.4 Cable entry shall normally be via glands and PVC/SWA/PVC cable. Cable type, quantity, and size to be advised to the Motor Manufacturer when ordering.

9. Tests

9.1 All tests shall be carried out in accordance with IEC 34-1.

9.2 Unless otherwise stated, Type Test certificates shall be provided for motors of 30kW and above.

9.3 Efficiency tests, where required, shall be carried out by the summation of losses procedures in accordance with IEC 34-2.

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Table A Motor Efficiency

Unless otherwise agreed, the efficiency of AC Induction motors at 100% and 75% load shall be not less than shown in the table below. Efficiency at 50% load shall be not less than 1.5% below these figures.

kW 5.5

7.5

11

15

18.5

22

30

37

45

Poles Effy% 2 86 4 86 6 85

2 87

4 88 6 87

2 88

4 88 6 88

2 89

4 89 6 88

2 90

4 90 6 89

2 91

4 91 6 90

2 93

4 92 6 92.5

2 93.5

4 93.5 6 93

2 93.5

4 94 6 94

kW 55

75

90

110

132

150

200

250

315

400

Poles Effy%2 94.5 4 94.5 6 94

2 95

4 95 6 95

2 95

4 95 6 95

2 95

4 95.5 6 95.5

2 95

4 95.5 6 95.5

2 96

4 96 6 95.5

2 96

4 96 6 95.5

2 96

4 96 6 96

2 96.5

4 96.5 6 96

2 96.5

4 96.5

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ABB Motors

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4. Upgrading Existing Plant

The following statement was recently published on behalf of the Europe Commission Directorate for Energy:

"In general it can be stated that the marginal efficiency improvements gained from high efficiency motors are not in themselves sufficient to justify replacement of the motors. However, if a motor is to be installed or if a motor has burnt out and may be rewound, then the additional cost of replacement by a high efficiency motor can usually be recovered in under two years."

The vast majority of industrial motors in use today are not of the energy efficient type. In some cases it is possible to justify upgrading an existing standard motor to a new energy efficient design and achieve a realistic payback period as shown by the North West Water study (see page 18).

However, the most practical time to upgrade is when a motor fails and a commercial decision has to be made whether to replace with a new energy efficient motor or repair the original.

Example: 75kW, 4 pole motor 8,000 hrs/year, 0.05p per kW/hr Annual running cost £34,000

NEW ABB MOTOR ABB Energy Efficient Motor Typical Capital Cost

£2,200

Annual energy saving over original motor before rewind (3% increased efficiency)

-£1,063

Actual cost in 1st year £1,137

ORIGINAL MOTOR REWIND Cost of Rewind £1,300

Increased annual cost with 1.1% efficiency loss due to rewinding

£ 395

Actual cost in 1st year £1,695

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This example shows although the new motor option has a higher capital cost, the impact of the increased running costs of the rewound motor and the savings from the energy efficient motor gives a payback of less than 12 months on this additional capital cost.

Replacement Guide The example above clearly shows commercial viability for replacing the motor, however, if the motor runs for short periods only or the engineering costs are high for retrofitting, the correct commercial decision would be to repair.

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4.1 Ontario Hydro Report

Experiment In an effort to determine the effect on performance caused by rewinding a motor, the Canadian utility Ontario Hydro conducted an experiment on nine rewound 15kW standard efficiency motors. Standard efficiency motors were used as they represent the majority of those in service.

The experiment entailed purchasing ten identical industrial motors and establishing their efficiency by testing to the relevant CSA standards at an independent facility. Nine motors then had a hole burnt in their end windings. Each of the damaged motors was then sent to a different rewind companies for rewinding. Once rewound, the nine motors were sent back to the same independent testing facility and re-tested.

The results are summarised below: New Rewound Change In

Motor Efficiency % Efficiency % Efficiency %1 87.7 84.3 -3.4 2 87.9 87 -0.9 3 88.5 87.9 -0.6 4 88.3 88 -0.3 5 87.5 86.5 -1 6 88.4 87.7 -0.7 7 87.6 87.2 -0.4 8 88.6 87.7 -0.9 9 88.3 86.8 -1.5

Average 88.1 87 -1.1

The main factors identified by the report which affected the efficiencies of the rewound motors were: • Excessive temperature during stripping, which damages laminations and

lamination insulation and increases core loss • The use of smaller conductors, which increases PR loss

The report concludes: "In many cases, failed standard efficiency motors should be scrapped and replaced by high efficiency models".

Copies of the full report are available from ABB Motors Ltd.

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ABB Motors

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4.2 Replacement Guide

The following guide is designed to assist your decision process and allow your motor management policy to operate smoothly.

The chart on page 13 defines the commercial viability of the replace or repair options. When a motor fails the only data needed for the correct decision to be made is the power rating and the annual running hours.

The chart is a guide based on the following typical operating parameters:

• Simple payback of 2 years • Average electricity unit cost of 5p per kWhr • Replacing with ABB standard range motors • Motor efficiency taken at 3/4 loading • Rewind costs at typical standard service charges • Rewind loss of 1.1% as described in the Ontario Hydro Report • Replacing motor population of standard efficiencies

This chart is suitable as a general guide for most operators. However, if a more accurate analysis with different operating parameters is required, a customised chart can be easily produced. Please contact ABB Motors for details.

Once established the system can be proved by an energy feasibility study and energy monitoring see page 16 for the services that ABB Motors can offer.

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4.3 Corporate Policy Flow Chart

The question of Energy Efficiency is not the only factor that will affect your decision policy.

When a motor fails there are a number of factors to be considered:

1) Is the failed motor metric or imperial? If the motor is imperial the engineering costs may be too high to consider replacement on that occasion. However, it should be noted that the metric motor is now the standard for all European manufacturing.

2) Is the failed motor too small to repair? Your company may already have identified a breakpoint power rating below which it is not viable to consider repair.

3) Has the motor been rewound before? The Ontario Hydro reports conclude that a rewind results in an average of 1.1% loss in efficiency, this figure may be compounded on subsequent rewinds. We recommend that Energy Efficient motors are rewound only once to maintain their advantage over standard motors.

Other factors may need to be considered to design a flow chart to tailor your own motor management policy, e.g. mechanical damage, availability, warranty, plant upgrades and reliability.

The chart on page 15 is a general guide to assist you in the creation of your own replacement policy flow chart.

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5. Energy Studies

To quantify the benefits of the use of Energy Efficient motors on your plant. ABB Motors can offer two methods of analysing and identifying areas of greatest savings. These studies can be tailored to your own requirement, but fundamentally fall into two categories:-

1. Non intrusive feasibility studies 2. Intrusive energy monitoring

The non intrusive feasibility study is usually undertaken first to identify the most favourable areas for energy monitoring.

Non Intrusive Feasibility Study

Many companies have available an inventory of the motors operating on their plant. If this is not available a site survey will identify the manufacturer, power rating and speed of all operating motors above a selected power rating. Once this is established the likely efficiency of these motors can be obtained from the original motor manufacturer's catalogue data.

If ABB are supplied with estimated plant running hours and an average unit cost then both individual and total running cost can be calculated. Once this has been established, savings and payback periods can be calculated on the basis that all motors are replaced with ABB energy efficient motors.

The example of a feasibility study carried out in a Blue Circle cement works (Page 17) shows a total possible saving of 119kW, but more importantly identifies specific areas for an energy monitoring study such as the FK compressors which would theoretically show an immediate payback on capital in 2.3 years.

Such an energy monitoring study will prove actual losses, which may be much higher due to a previous rewind or other operating factors, for example faulty bearings.

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ABB Motors

The Way Forward BLUE CIRCLE CEMENT MOTOR STUDY

INSTALLED MOTOR REPLACEMENT ABB MOTOR

Motor description MANFR kW Poles EFFY

%Losses kW

ABB Motor

EFFY %

Losses kW

Saving Of Losses kW

Savings Per Year

Payback years

Clay Quarry 2205 hrs/yr Slurry Pump No1 BCP 150 4 93 8.47 M2BA315 96.00 4.69 3.78 £291.74 13.20Slurry Pump No2 Newman 110 4 92 7.17 M2BA280 95.70 3.71 3.47 £267.57 10.76Slurry Pump No3 Newman 110 92 7.17 M2BA280 95.70 3.71 3.47 £267.57 10.76Slurry Pump No4 BCP 45 £ 92 2.93 M2BA225 94.20 2.08 0.86 £66.12 17.36Chalk Quarry 2940 hrs/yr Slurry Pump No1 BCP 75 A 91.5 5.23 M2BA250 95.10 2.90 2.33 £239 7.25Slurry Pump No2 CP 75 4 92 4.89 M2BA250 95.10 2.90 1.99 £205 8.46Slurry Pump No3 GEC 110 4 93.5 5.74 M2BA280 95.70 3.71 2.03 £209 13.79Slurry Pump No4 GEC 110 4 93.5 5.74 M2BA280 95.70 3.71 2.03 £209 13.79Slurry Pump No7 BCP 132 4 92.5 8.03 M2BA315 95.80 4.34 3.69 £379 8.80Compressor Newman 75 2 90 6.25 M2BA250 95.30 2.77 3.48 £358 5.73Belt Conveyor No1 CP 37 4 91 2.74 M2BA225 93.70 1.87 0.88 £90 10.84Belt Conveyor No2 CP 37 4 91 2.74 M2BA225 93.70 1.87 0.88 £90 10.84Belt Conveyor No3 CP 37 4 91 2.74 M2BA225 93.70 1.87 0.88 £90 10.84Belt Conveyor No4 BCP 37 4 91 2.74 M2BA225 93.70 1.87 0.88 £90 10.84Belt Conveyor No5 BCP 37 4 91 2.74 M2BA225 93.70 1.87 0.88 £90 10.84Belt Conveyor N06 CP 37 4 91 2.74 M2BA225 93.70 1.87 0.88 £90 10.84Belt Conveyor No7 BCP 37 4 91 2.74 M2BA225 93.70 1.87 0.88 £90 10.84Chalk Kibbler Cambridge No1 BCP 37 4 91 2.74 M2BA225 93.70 1.87 0.88 £90 10.84Chalk Kibbler Cambridge No2 BCP 37 4 91 2.74 M2BA225 93.70 1.87 0.88 £90 10.84Chalk Kibbler Masons No1 BCP 37 4 91 2.74 M2BA225 93.70 1.87 0.88 £90 10.84Chalk Kibbler Masons No2 BCP 37 4 91 2.74 M2BA225 93.70 1.87 0.88 £90 10.84Packing Plant 2940 hrs/yr Feed Screw Motor No1 CP 37 4 91 2.74 M2BA225 93.70 1.87 0.88 £90 10.84Feed Screw Motor No2 CP 37 4 91 2.74 M2BA225 93.70 1.87 0.88 £90 10.84Exhaust Fan GEC 30 4 90.5 2.36 M2BA200 93.00 1.69 0.67 £69 9.93Kiln 8064 hrs/yr Kiln Cooler Fan No1 BCP 45 4 91.5 3.14 M2BA225 94.20 2.08 1.06 £298 3.85Kiln Cooler Fan No2 BCP 45 4 91.5 3.14 M2BA225 94.20 2.08 1.06 £298 3.85Dust Wetter Main Screw EE 45 6 92 2.93 M2BA250 94.20 2.08 0.86 £242 5.53Kiln Feed Pump No1 CP 30 4 91 2.23 M2BA200 93.00 1.69 0.53 £150 4.55Kiln Feed Pump No2 CP 30 4 91 223 M2BA200 93.00 1.69 0.53 £150 4.55LIW FK Pump CP 45 4 92 2.93 M2BA225 94.20 2.08 0.86 £242 4.75No1 Compressor GEC 55 2 91.5 3.83 M2BA250 94.50 2.40 1.43 £404 3.98Precip Dust FK Pump BCP 45 6 92 2.93 M2BA250 94.20 2.08 0.86 £242 7.13Dust Collector FK Pump CP 90 6 92 5.87 M2BA315 95.40 3.25 2.61 £738 4.62Dust Collector FK Compressor CP 45 4 92 2.93 M2BA225 94.20 2.08 0.86 £242 4.75LIW FK Pump Compressor EE 75 6 93 4.23 M2BA280 95.00 2.96 1.27 £359 8.10Kiln House Compressor No1 BCP 75 12 N/A M2BA315 Kiln House Compressor No2 BCP 75 12 N/A M2BA315 Kiln House Compressor No3 BCP 75 12 N/A M2BA315 Cooler Exhaust Fan BCP 150 6 93.5 7.82 M2BA355 95.90 4.81 3.01 £850 6.45Pump House 8064 hrs/yr Pump No1 BCE 22 2 91 1.63 M2BA180 92.50 1.34 0.29 £83 6.81Pump No2 BCE 22 2 91 1.63 M2BA180 92.50 1.34 0.29 £83 6.81Site Slurry Pumps 2912 hrs/yr Slurry Pump No1 CP 45 4 92 2.93 M2BA225 94.20 2.08 0.86 £87.32 13.15Slurry Pump No3 Newman 55 4 90 4.58 M2BA225 94.70 2.31 2.27 £231.84 5.68Slurry Pump No4 GEC 55 4 92.5 3.34 M2BA250 94.70 2.31 1.04 £105.59 12.46Mill House No1 7200 hrs/yr FK Pump EE 75 6 92.5 4.56 M2BA280 95.20 2.84 1.72 £434.62 6.70FK Compressor No1 Newman 75 2 90 6.25 M2BA250 95.30 2.77 3.48 £875.92 2.34FK Compressor No2 Newman 75 2 90 6.25 M2BA250 95.30 2.77 3.48 £875.92 2.34Mill House No2 7200 hrs/yr FK Pump EE 90 6 93.5 4.69 M2BA315 95.40 3.25 1.44 £362.32 9.41 Compressor No1 Stromberg 75 4 94.5 3.27 M2BA250 95.10 2.90 0.38 £94.64 18.34Compressor No2 Stromberg 75 4 94.5 3.27 M2BA250 95.10 2.90 0.38 £94.64 18.34Compressor No3 Stromberg 75 4 94.5 3.27 M2BA250 95.10 2.90 0.38 £94.64 18.34

TOTAL 3.167MW 189.7kW 119.51 kW 70.19kW £11,369 7.05

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INTRUSIVE ENERGY MONITORING

EXAMPLE. NORTH WEST WATER

ABB Motors completed a feasibility study, which indicated a number of motors suitable for energy monitoring, based on North West Water's own criteria. North West Water then requested ABB to continue and undertake a full energy monitoring survey.

The example given shows clearly it can be cost effective to upgrade to a new energy efficient motor before failure occurs. The existing motor was monitored for seven days, it was then replaced by a new energy efficient motor and monitored for a further seven days.

The results are given in graphical form and annual energy costs calculated ,the payback achieved was well inside the limit given by North West Water. The feasibility study and energy monitoring gave important information to help North West Water complete their Motor Management policy.

Motor Details: Existing Motor: ABB Motor:

90 kW, 4 Pole Frame Size 280S Frame Size 280SMB

Existing Motor ABB Motor

Weekly running cost = £557 Weekly running cost = £523

From the above graphs, we can obtain the annual running cost

Existing Motor: £557 x 52 gives running costs of £28,964.00 per annum

ABB Motor: £523 x 52 gives running costs of £27,196.00 per annum.

The ABB motor shows a saving of £1,768.00 p.a., which gives a typical payback period of 1.8 years

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ENERGY EFFICIENT MOTORS

Twenty Questions & Answers

1. Q. What is an Energy Efficient Motor?

A. An Energy Efficient Motor produces the same output power (torque) but uses less electrical input power (kW) than a standard efficiency motor.

2. Q. How is an Energy Efficient Motor different to a standard motor9

A. Energy Efficient Motors are manufactured using the same standard frame sizes but have:

• Higher quality and thinner laminations in the stator, reducing core loss • More copper in the slots reducing PR loss • Reduced fan losses • Reduced stray losses

3. Q. Are all new motors Energy Efficient Motors?

A. No. ABB motors are all Energy Efficient as standard, other manufacturers offer high efficiency ranges, often at a premium price.

4. Q. Are Energy Efficient Motors widely available?

A. ABB Energy Efficient Motors are available off the shelf from local and national distributors.

5. Q. Are Energy Efficient Motors available for hazardous area application?

A. Yes, because ABB uses the same energy efficient components across its complete range of 3 phase motors.

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6. Q. Do Energy Efficient Motors require more maintenance?

A. No, Energy Efficient Motors have the same maintenance requirements as standard motors.

7. Q. What is the range of Energy Efficient Motors available?

A. Energy Efficient Motors are available in all speed ranges from 2.2kW-700kW in low voltage.

8. Q. Can Energy Efficient Motors replace my existing motors on site?

A. Yes, any metric motor can be directly replaced by an Energy Efficient Motor. If you are replacing an imperial (inch frame) motor, some modification will be required.

9. Q. Should 1 rewind my standard efficiency motor or replace with an Energy Efficient Motor?

A. An Energy Efficient Motor will result in lower energy costs when compared with a rewound motor. In simple terms its cost effectiveness will depend upon the duty and the difference in the cost of the rewind and the capital cost of the Energy Efficient Motor (guidelines for Energy Efficient Motor purchases versus rewinds are given on page 13).

10. Q. Can a standard motor be rewound as an Energy Efficient Motor?

A. It is possible for a standard motor to have what is called a "high efficiency rewind" (usually at a higher cost than a standard rewind). This rewind procedure can increase the efficiency of a standard motor above its original level. However, the efficiency would still be lower than that of a new Energy Efficient Motor because the energy losses in the stator core cannot be reduced.

11. Q. Can an Energy Efficient Motor be rewound?

A. Yes, but if rewinding reduces efficiency the advantages over a standard motor will be lost

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12. Q. What is the effect of partial loading on an Energy Efficient Motor?

A. The benefit of using an energy efficient motor is even greater at partial load. This is because the difference in efficiency between an energy efficient motor and a standard motor increases as the load decreases, (see page 23).

13. Q. How can I ensure receiving Energy Efficient Motors?

A. When purchasing motors through a third party, such as pump and fan equipment suppliers, it is important to specify the minimum efficiencies you will accept. Use the draft specification in section three as a guide to writing your own motor specification.

14. Q. How reliable are Energy Efficient Motors?

A. Energy Efficient Motors have at least equal reliability as standard efficiency motors. In some cases they have a longer life because of lower motor operating temperatures.

15. Q. Can the efficiencies quoted by different manufacturers be compared?

A. Yes, in general major European motor manufacturers' catalogue data can be compared and type test certificates showing performance can be requested.

16. Q. Is efficiency calculated in the same way by all manufacturers?

A. No. All European manufacturers test to IEC standards which use the summation of losses method. There are two other standards, American NEMA and Japanese JEC, these will give different efficiency results.

17. Q. How much reduction in energy costs will Energy Efficient Motors give?

A. Savings can be considerable, energy saving is dependant on a number of factors:

• kW rating of motor • Loading of motor • Hours run • Cost of electricity

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18. Q. Do Energy Efficient Motors have the same noise levels as standard efficiency motors?

A. No. The smaller cooling fan on Energy Efficient Motors, reduces windage losses and decreases overall motor noise levels.

19. Q. Can Energy Efficient Motors be used on variable speed drive applications?

A. Yes, Energy Efficient Motors can be used for all the same applications as standard efficiency motors. For V.S.D. application, Energy Efficient Motors ran at lower temperature due to the thinner, low loss lamination steel, which reduces the harmful effects of harmonics.

20. Q. Where can I obtain further information on the use of Energy Efficient Motors?

A. The Department of Environment publishes further information on the use of higher efficiency motors. This can be obtained from:

The Enquiries Bureau ETSU Harwell OxonOX11 0RA Tel: 01235 436747

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