easa motor repair slides

8/18/2019 EASA Motor Repair Slides

1/38

Motor Management Truths

and Consequences:Understanding Electric Motor

Rewinds and Efficiency

MDM Webcast

May 25, 20112 - 3 p.m. Eastern


2/38

2

Housekeeping

Web Portion

Ensure that your pop-up blocker is turnedoff and Java is enabled

Minimize the numberof applications running

Use the chat featureduring presentation

Audio Portion

Dial *0 to speak to aRollCall operator

Dial *6 toMute/UnMute

Be sure that hold

music is turned off


3/38

3

Today’s Web cast

• MDM and motor management strategies

• Overview of motor repair and rewinds

• Mechanical rebuilding and rewinding

• Effects of repair and rewind on efficiency

• Resources and considerations

• Questions and Answers


4/38

4

MDM Sponsors

Manufacturers – Motor & Drive• ABB• Danfoss• GE Energy Motors• TECO-Westinghouse Motor

Company

Other Organizations• Advanced Energy

• Copper Development Association,Inc. (CDA)• Electrical Apparatus Service

Association (EASA)

Efficiency Programs• Alliant Energy

• BC Hydro• Efficiency Vermont

• Long Island Power Authority (LIPA)• MidAmerican Energy Company• National Grid USA • New Jersey Office of Clean Energy• New York Power Authority (NYPA)• NYSERDA• Northwest Energy Efficiency Alliance• Pacific Gas & Electric (PG&E)• Southern California Edison (SCE)

• Tennessee Valley Authority (TVA)• Xcel Energy

For more information, visit: http://www.motorsmatter.org/sponsors/

http://www.motorsmatter.org/sponsors/http://www.motorsmatter.org/sponsors/


5/38

5

Motor Decisions Matter SM

Managed by CEE, a national awareness campaign to:

• Encourage sound motor management, including – Demonstrate financial benefits of life cycle cost analysis – Inform motor repair-replace decisions

– Promote premium efficiency motors and

best practice motor repair


6/38

6

Effective Motor Management


7/38

Tom Bishop, P.E.Electrical Apparatus

Service Association, Inc.

St. Louis, MO

Motor Management

Truths and Consequences: Understanding

Electric Motor Rewinds and Efficiency


8/38

8

Background: What is EASA• Electrical Apparatus Service Association

• Trade association serving the electrical andmechanical apparatus sales, service and repairindustry

• Founded in 1933• More than 1,900 member firm locations worldwide;

approximately 1,400 in the U.S.

• Supports its members with industry research,engineering services, and education

• Establishes industry standards and practices


9/38

9

Motor Repair and Rewind

Overview

• All repairs include mechanical rebuilding

Some repairs require rewinding

• Repair truths and consequences

• Key resources• Key factors that influence the repair

decision


10/38

10

Rewind versus All Repairs

Source: A Survey of Faults ..., IEEE Petroleum and Chemical Industry Paper No. PCIC-94-01.


11/38

11

Mechanical Rebuilding• Consists of

Test and inspectDisassemble

Cleaning/overhaul

Measurement of mechanical fitsBearing replacement

Restore mechanical fits and components

Assemble and test

• Most repairs are mechanical rebuildingwithout rewinding


12/38

12

Mechanical Rebuilding

• Test and inspect

• Disassemble

• Cleaning/overhaul


13/38

13


• Measurement of fits

• Bearing replacement

• Restore mechanical fits

and components


14/38

14


• Assemble and test

• Final step after

mechanical repair withor without rewind


15/38

15

Rewinding

• A sub-process to

mechanical rebuilding• Random (round wire)

windings• Form coil windings


16/38

16

Rewinding

• Resin treatment

and curing

• Electrical testing


17/38

17

Effect of Repair and Rewind on

Efficiency

• Truths

• and Consequences


18/38

18

Truths• Rewinding using

best practicesMaintains efficiency

May improve

efficiency


19/38

19

Truths• Maintain efficiency by

Copy-rewind or windingpattern improvement

Using same windingcoil wire area

Using same average

length of turns


20/38

20

Truths• Opportunity to improve

efficiency byUsing larger winding

coil wire area

Reducing average

length of turns

Average length of turn

= (2 x Ls) + (4 x Lc)

Wire Size: AWG 16

Bare Diameter = .0508

Wire Size: AWG 17


Wire Size: AWG 17



21/38

21

Truths• Efficiency does not change with

subsequent rewindsCore losses do not increase

Winding data rarely changes


22/38

22

Truths• Repairing can restore:

Reduction in efficiencydue to prior repairs

• Restoration associated

with a rewind

• Restoration associatedwith mechanical repair


23/38

23


Reduction in efficiencydue to damage from

motor failure(s)

• Associated with

winding failure(s)

• Associated withmechanical failure(s)


24/38

24


Motors to like-newcondition

Sometimes even better

than new

• Repairs can enhancesuitability of motor forits application and

environment


25/38

25

Consequences• Consequences of poor

practice repairs:Reduced efficiency

Reduced reliability


26/38

26

Consequences• Reduction in efficiency

can occur Core damage due to

winding removal

Not the only reason for

reduction in efficiencyduring repair…


27/38


28/38

28

Consequences• Consequences of best practice repairs:

Efficiency maintained

• Efficiency may be improved

Reliability maintained

• Reliability may be improved

Motor description

Efficiency

before rewind

Efficiency

after rewind Efficiency change Comments

7.5hp 4 pole 83.2% 84.0% +0.8%concentric to lap5 burnouts 1 rewind

100hp 4 pole 93.0% 93.6% +0.6% full to half slot lap

100hp 4 pole 93.0% 93.7% +0.7% 3rd rewind

150hp 2 pole 95.9% 95.9% 0.0% full to half slot lap1st and 2nd rewinds

Source: EASA/AEMT Motor Rewind Study, 2003


29/38

29

Key Resource Documents• ANSI/EASA AR100 2010

Recommended Practice for the Repair ofRotating Electrical Apparatus

•EASA/AEMT Rewind StudyThe Effect of Repair/Rewinding on Motor

Efficiency

• EASA Tech Note 16

Guidelines for Maintaining Motor Efficiency

During Rebuilding


30/38

30

ANSI/EASA AR100• The American National

Standard for repair ofrotating electrical apparatus

• Purpose: establishguidelines in each step ofelectrical apparatus

rewinding and rebuilding• Concisely (22 pages)

describes best practice

repairs


31/38

31

ANSI/EASA AR100 Benefits• Provides guidance for service centers to

perform best practice repairs• End users are assured that compliant

repairs follow a national standard

• Results:

Quality repairs

Reliable repairs

Efficiency maintained


32/38

32

ANSI/EASA AR100 Content• GeneralIdentification, inspection, condition assessment,failure analysis, cleaning, transport

• Mechanical repair Shafts, bearings, lubrication14 fit and tolerance tables

• Rewinding

Core inspection, winding removal, windingspecification

• Testing

Insulation resistance, high-potential, surge,core laminations, no-load


33/38

33

EASA/AEMT Rewind Study

Key content: Good Practice Guide

• Inspection and dismantling

• Testing

• Winding removal and rewind

• Mechanical repairs

• Reassembling


34/38

34

EASA/AEMT Rewind Study

Key content: Good Practice Guide

• Lessons learned

Guide good practices AR100 best practices

• Provides source details forgood/best practices

Repair reference document

for service centers

Specification reference

document for end users


35/38

35

EASA Tech Note 16*

Key content

• Do’s include

Core test before and afterwinding removal

Repair or replace defectivelaminations

Evaluate impact on efficiency ifwinding design changes

• Don’ts includeOverheat stator core/use openflame

Short laminations when

grinding/filing Increase winding resistance

* Guidelines for Maintaining

Motor Efficiency During

Rebuilding


36/38

36

Key factors in repair or rewind

decision• Horsepower rating

Economic evaluation

• Motor type/features

Availability of new• Maintenance history

Evaluate reliability


37/38

37

Questions?

Thank You!

www.easa.com

http://www.easa.com/http://www.easa.com/


38/38

38

Contact Information

• Motor Decisions Matter Campaign

– www.motorsmatter.org

– Email: [email protected]

– Sign up for E-Newsletter

• MDM Events Calendar

– www.motorsmatter.org/events/calendar.asp – Will include slides from today’s webcast
http://www.motorsmatter.org/mailto:[email protected]://www.motorsmatter.org/events/calendar.asphttp://www.motorsmatter.org/events/calendar.aspmailto:[email protected]://www.motorsmatter.org/