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Infrared thermography on electrical system
By
Name: Venkanagouda P.C
USN:
Under the Guidance of
Prof.Praveen .H
A seminar on
• Department of Electrical and Electronics Engineering
K. L. E. Institute Of Technology, Hubli.
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Contents
 Introduction
 What is thermography
 Test instrument
 Inspection of components and faults
 Condition monitoring
 Electrical applications
 Benefits of infrared thermography
 Advantages and limitations
 Case studies
 Conclusion
 References
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Introduction
 In 1800, astronomer Sir William Herschel discovered infrared
 It is simply a picture of heat
 On-line condition monitoring
 fast, reliable and accurate temperature profile of any material surface.
 New level of diagnostic aid and problem solving
 Rapid growth in electric utilities and industrial sectors are embracing the
technology.
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Infrared thermography_What it is?
An Infrared Camera Senses Infrared Radiation
It is objective image-giving measuring method
Enabling Us To Visualize The Thermal World
surface temperature can be determined contactless.
A Processor In The Camera Assigns Color To The Infrared Radiation-
Different Color Equals Different Temperature
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In an electromagnetic spectrum the IR region appears between 0.8
micron to 1000 micron wavelength . This wavelength of IR spectrum is
more than that of a visible spectrum
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Test Equipment
Hand held portable camera
Battery Powered
Range…..-20°c to +1500°c
Sensitivity…..0.1°c at 30°c
Real time display
Image Recording capability
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 The infrared camera evaluates and converts heat energy into
meaningful temperatures. Components in various states of failure
will emit more heat as a direct result of more energy dissipated into
the component.
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Objectives of Test
 To detect hot or cold area’s
 To determine absolute temperature
 To view Thermal profiles
 To detect temperature loss
 first determine a baseline
 baseline is established when the system is operating under normal load and
operating conditions
 the baseline images and data will be stored and compared to new data
collected from each inspection interval
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Electrical Inspection Items
. Transformer
– Pad Mount
– Dry
– Overhead
• Distribution Panels
• Rectifiers
• Control Panels
• Drives
• Capacitor Banks
• Any Electrical Connection
• Main Switchgear
• Motor Control Centers
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Typical Faults in a electrical network
Electrical Distribution
Equipment
Transformers
Motors
Loose connections or poor contacts,
unbalanced loads, overloading, overheating
Loose connections, overheated bushings,
poor contacts, overloading, blocked
/restricted cooling passages
Overheated bearings, unbalanced loads,
overheating /overloading, blocked cooling
passages
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Electrical Applications
 Power generation: hydro, thermal, and nuclear
 Power distribution: transmission, switchyards, substations,
and distribution
 Industrial users: all process and manufacturing industries
 Commercial users: warehouses, office buildings, banks,
schools, virtually all buildings
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Condition monitoring
 No electrical system is 100% efficient
 Temperature is an excellent indicator to the operating condition
 It is well understood that the life of electrical components and materials is drastically
reduced as temperatures are increased.
 IEEE, ANSI, IEC and manufacturers all publish standards and temperature ratings
for electrical components
 the job of the thermographer to identify record, analyze and diagnose indications of
abnormal heat transfer in the electrical equipment or components
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Exception Repair Priority Criteria
Priority 0
Temperature Difference 10F or Less
No Corrective Measures Required
At This Time.
Priority 4
Temperature Difference Over 100F
Corrective Measures Required Immediately
Priority 3
Temperature Difference 30F to 100F
Corrective Measures Required
As Soon As Possible
Priority 2
Temperature Difference 20F to 30F
Corrective Measures Required
As Scheduling Permits
Priority 1
Temperature Difference 10F to 20F
Corrective Measures Required
At Next Maintenance Period
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Exception Example Breaker Load
Hot Spot Temperature….71F
Reference Temperature…55F
Temperature Difference..16F Repair Priority 0
No Corrective Measures Required
At This Time
92.6°F
119.1°F
95
100
105
110
115
Breaker Load A-105 amps
B-150 amps
C-167 amps
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Exception Example
Main Switchboard Fused Switch
Hot Spot Temperature...311F
Reference Temperature..151F
Temperature Difference...160F
Repair Priority 4
Corrective Measures Required
Immediately
118.9°F
245.4°F
120
140
160
180
200
220
240AR01
SP01
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Application in distribution system
 Isolators, circuit breakers, Current Transformers, Potential Transformers,
Distribution Transformers, bus bars etc. Most faults are encountered in
the form of hot-spots at contact terminals which may be due to lose
contact, corrosive nuts & bolts, broken conductor strands etc
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Applications Power Circuit of Electrical Drives
 loose contacts at Motor Control Centre's
 severe voltage unbalance is at the motor terminal end lead to single-phasing
 This results in malfunctioning of the motor
 415 volt 75 KW induction motor (101 0C) at MCC breaker terminal with
ambient about 30 0C in R-phase resulting in a voltage unbalance of about
4.7% at motor terminal
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Benefits of Periodic Electrical Infrared Inspections
 Predictive Maintenance...Allows Scheduling Of Repairs, Forward
Buying. The reduction in disassembling, rebuilding or repairing
components
 Reduces Downtime… Find It, Repair It, Before It Blows Up and
Stops Production
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 Safety
 Greater system security
 Improved and less expensive maintenance
 More efficient inspections
 Reduced outage and operational costs
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Advantages and Limitations
Advantages Limitations
•It is a non-contact type technique.
•Fast, reliable & accurate output.
•A large surface area can be scanned in no time.
•Presented in visual & digital form.
•Software back-up for image processing and
analysis.
•Requires very little skill for monitoring.
•Can work at a distance
•Portable
•Convincing Results
•Cost of instrument is relatively high.
•Unable to detect the inside temperature if the
medium is separated by
•glass/ polythene material etc.
•Operator experience is essential
•Filters may be needed for certain applications
•Sensitivity and Resolution reduce with distance
and angle of view
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Case study 1
Consequence of Application of Thermography in a switchyard of a
Captive Power Plant
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Case study 2
Transformer
 Excessive transformer loading.
 Excess current in the neutral of the
transformer.
 Problems in the cooling system.
 High harmonic content in the power
supply.
 Sustained overvoltage which exists for a
long period of time.47.2°C
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Case study 3
Transmission lines
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A high-temperature spot is found at the connector of phase-T
conductor at the jumper of the riser pole.
it shows bad electrical
connection

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Conclusions
 Protect catastrophic equipment failures and unscheduled plant
shutdowns
 a fast, reliable and accurate
 maintenance priorities, enhance operational safety and contribute to a
stronger bottom line.
 Enhancing and preserving system reliability and reducing
maintenance costs
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$1.00 $4.00

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REFERENCES
 FLIR Infrared Cameras Help Detect the Spreading of Swine Flu and Other Viral Diseases Applegate.co.uk (2009-
04-29). Retrieved on 2013-06-18.
 Poryev V.A., Poryev G.V. "Experimental determination of the temperature range of a television pyrometer" in
Journal of Optical Technology, Volume 71, Issue 1, pp. 70–71 (2004)
 Maldague X. P. V., Jones T. S., Kaplan H., Marinetti S. and Prystay M. "Chapter 2: Fundamentals of Infrared and
Thermal Testing: Part 1. Principles of Infrared and Thermal Testing," in Nondestructive Handbook, Infrared and
Thermal Testing, Volume 3, X. Maldague technical ed., P. O. Moore ed., 3rd edition, Columbus, Ohio, ASNT
Press, 2001, 718 p..
 Infrared Temperature Theory and Application. Omega.com. Retrieved on 2013-06-18..
 Snell, J.; Renowden, J. (2000). "Improving results of thermographic inspections of electrical transmission and
distribution lines". 2000 IEEE ESMO – 2000 IEEE. ESMO 2000 Proceedings. Global ESMO 2000. The Power is
in Your Hands (Cat. No.00CH37183). p. 135.doi:10.1109/TDCLLM.2000.882811. ISBN 0-7803-6625-5.
 http://halut.tripod.com/infrared.htm 25

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Thank you……