0. Overview & Benefits of Thermographic Inspection
4/22/2017
Overview & Benefits of Thermographic Inspection
SWEDE Conference
Michael Navarro
May 2007

1. 4/22/2017
WHAT IS THERMOGRAPHY?
Infrared (IR) radiation is electromagnetic radiation of a wavelength longer than that of visible light, but shorter than that of radio waves. The name means "below red" (from the Latin infra, "below"), red being the color of visible light of longest wavelength.
Infrared radiation is popularly known as heat, heat radiation, or “hot spots”.
Infrared radiation can be used to remotely determine the temperature of objects. This process is commonly called “Infrared” in the electric utility industry.

2. Benefits of Thermographic Inspections
4/22/2017
Benefits of Thermographic Inspections
Proactive thermographic inspections on Transmission and Distribution systems have proven:
Improvement in our SAIDI and SAIFI metrics
Reduced equipment failures, resulting in less capital spend
Reduction in O&M spend as a result of less reactive restoration, usually during overtime hours.
Improved reliability, or more specifically, a reduction in outages has a positive impact on customer satisfaction

3. Recommendations for Targeted Inspection
4/22/2017
Recommendations for Targeted Inspection
Transmission Substation and equipment inspection
Distribution feeder main line inspection that is accessible by vehicle
Arresters, air switches, voltage regulators, capacitor banks, connectors, fused disconnects, insulators, solid disconnects, transformers, regulators, reclosers, riser pole terminations
Major Equipment - Switchgear, three-phase transformers, auto transformers, automatic transfer equipment, walk in vaults. Manholes are not included because of OSHA requirements for working in manholes
Special Request/Event inspections
Sporting events, convention facilities, fairgrounds, and any televised event

4. Recommendations for Targeted Inspection (Cont.)
4/22/2017
Recommendations for Targeted Inspection (Cont.)
Government Facilities, Hospitals, Water Supply
Emergency infrared inspections can be utilized as a trouble shooting tool
Additional component of the Infrared Inspections is a detailed report which includes:
Delta T or Ambient temperature
FLIR software and reporting tools
NETA (National Electrical Testing Association) priority rating criteria

5. Oncor Electric Delivery’s History
4/22/2017
Oncor Electric Delivery’s History
1970’s
Nitrogen cooled camera held out of truck window
1993
Oncor system wide central program established with a Technical Services group.
Infrared inspect 2700 feeders & 800 substations per year
EPRI Project

6. Oncor Electric Delivery’s History (Cont.)
4/22/2017
Oncor Electric Delivery’s History (Cont.)
2001
Transmission began inspection of substations
Improved quality by inspecting 1/3 of feeders
Optimized methodology identifying “hot spots”
2002
Performance Based Inspection (10% Worst Performing Feeders)
Overhead and Underground Facilities inspected
2003
Performance Based Inspections produced a higher % of hot spots with a higher priority rating while scanning fewer feeders
Spot checking new terminations
Added portable cameras

7. Oncor Electric Delivery’s History (Cont.)
4/22/2017
Oncor Electric Delivery’s History (Cont.)
2004
Performance Based Inspections continued and more Underground Distribution facilities targeted
2005
Performance Based Inspections increased (20% WPF)
Additional Underground Distribution facilities targeted
$500,000 for Infrared Inspections contracted outside of company
2006
Performance Based Inspections continue

8. When to Perform Thermographic Inspections?
4/22/2017
When to Perform Thermographic Inspections?
Thermographic Inspections can be performed year round
Delta T process for Infrared allows this by using temperature rise over reference equipment rather than rise over ambient
Winter peaking feeders can be targeted
High visibility on darker days helps to identify anomalies

9. Criteria for Determining the Priority Rating for Repair
4/22/2017
Criteria for Determining the Priority Rating for Repair
Consumers Affected
The estimated number of consumers that may be affected and the type of equipment affected is taken into consideration. By using this information and the temperature of the hot spot along with the Thermographer’s experienced- based knowledge, the anomaly will be rated.
Priority 1…..low priority
Priority 2…..low priority
Priority 3…..work as you can
Priority 4…..within 24 hours (high priority)
Priority 5…..repair immediately (safety or imminent outage)

10. What Criteria Determines the Priority Rating For Repair?
4/22/2017
What Criteria Determines the Priority Rating For Repair?
Wind
If the wind is greater than 15 mph, it will reduce the temperature measured by half. Wind speed will be measured by using either an instrument located on the truck or by local weather forecast Load and Time
Load and Time
The Load and Time of day will help determine the probability that as the day progresses the load will increase and the temperature of the hot spot will also increase. The Thermographer will use experience based knowledge and available data to derive at the grading of this priority
Safety Concerns
If there is a Safety Concern the hot spot will then be considered as a Priority 5 – repair immediately

11. 4/22/2017
Benefits
There are several benefits for performing Infrared Inspections on the electrical system.
Enhanced operational safety and reliability of the system
SAIDI/ SAIFI improvements
Increased material and equipment life, resulting in capital savings
Proactively identifies workmanship issues
Maintenance cost reduced by preventing unscheduled outages
The only predictive maintenance available (***)
Saves you money

12. Equipment Required to Support Thermography
4/22/2017
Equipment Required to Support Thermography

13. Equipment Required to Support Thermography
4/22/2017
Equipment Required to Support Thermography

14. Equipment Required to Support Thermography
4/22/2017
Equipment Required to Support Thermography

15. Equipment Required to Support Thermography
4/22/2017
Equipment Required to Support Thermography

16. Equipment Required to Support Thermography
4/22/2017
Equipment Required to Support Thermography

17. Equipment Required to Support Thermography
4/22/2017
Equipment Required to Support Thermography

18. 4/22/2017
Examples
212.5 degrees C
Temperature of Hot Spot –239.2 degrees C – Solid blade disconnect switch
Temperature of Spot 1 –26.7 degrees C – Solid blade disconnect switch
Delta T temperature – degrees C – rise above reference
OUTAGE OCCURRED PRIOR TO REPAIR INVOLVING 203 CUSTOMERS FOR 3 HRS 2 MIN FOR 36,945 CUST MIN
INFRARED INSPECTION PERFORMED AND EQUIPMENT FAILED

19. Examples (Cont.) 4/22/2017 54.2 degrees C
Temperature of Hot Spot –86.3 degrees C – Solid blade disconnect switch pothead connection on 2 phases
Temperature of Spot 1 –32.1 degrees C – Solid blade disconnect switch
Delta T temperature – 54.2 degrees C – rise above reference
OUTAGE OCCURRED PRIOR TO REPAIR INVOLVING 1590 CUSTOMERS FOR UP TO 2 HRS 52 MIN
FOUR STAGE RESTORATION FOR 190,186 CUSTOMER MINUTES
INFRARED INSPECTION PERFORMED AND EQUIPMENT FAILED

20. Examples (Cont.) 4/22/2017 79.6 degrees C
Temperature of Hot Spot –118.4 degrees C – Air Break Switch Middle Phase
Temperature of Spot 1 –38.8 degrees C – Air Break Switch
Delta T temperature – 79.6 degrees C – rise above reference
OUTAGE OCCURRED PRIOR TO REPAIR INVOLVING 2398 CUSTOMERS FOR UP TO 1 HRS 1 MIN
TWO STAGE RESTORATION FOR 27,588 CUSTOMER MINUTES
INFRARED INSPECTION PERFORMED AND EQUIPMENT FAILED

21. 4/22/2017
Examples (Cont.)
Temperature of Hot Spot – 53.1 degrees C – blade of switchgear
Temperature of Spot 1 – 42.6 degrees C – reference blade of switchgear
Delta T temperature – 10.5 degrees C – rise above reference

22. 4/22/2017
Examples (Cont.)
Temperature of Hot Spot – 81.5 degrees C – capacitor oil switch
Temperature of White Arrow Spot – 41 degrees C – reference capacitor oil switch
Delta T temperature – 40.5 degrees C – rise above reference

23. 4/22/2017
Examples (Cont.)
Temperature of Hot Spot – degrees C – H squeeze connection
Temperature of White Arrow Spot – 33.6 degrees C – reference H squeeze connection
Delta T temperature – degrees C – rise above reference

24. 4/22/2017
Examples (Cont.)
Temperature of Hot Spot – 66.5 degrees C – elbow connection
Temperature of Spot 1 – 39.3 degrees C – reference elbow connection
Delta T temperature – 27.2 degrees C – rise above reference
INDIRECT HOT SPOT – WHILE REPAIRING, THE ELBOW CRUMBLED IN THE HANDS OF THE WORKER

25. 4/22/2017
Examples (Cont.)
Temperature of Hot Spot – 32.5 degrees C – All 3 terminations
Temperature of Spot 1 – 27.7 degrees C – reference top of termination
Delta T temperature – 4.8 degrees C – rise above reference
HOT SPOTS THAT APPEAR TO BE WHERE THE SEMI-CON IS CUT TOO DEEP DURING PREPARATION IS ACTUALLY A TERMINATION APPLIED INCORRECTLY ALLOWING A VOID THAT CREATES PARTIAL DISCHARGE

26. 4/22/2017
Examples (Cont.)
Temperature of Hot Spot – 59.6 degrees C – All Arresters
Temperature of Spot 1 – 27.3 degrees C – Primary Bushing
Delta T temperature – 32.3 degrees C – rise above reference

27. History - Ranking of “Anomalies”
4/22/2017
History - Ranking of “Anomalies”
696
1684
2061
2662
1549
Total

28. Infrared Inspection Items
4/22/2017
History - Identified “Anomalies” by Device
1549
2662
2061
1687
1259 1 3 2
Weather heads
Vacumn Switch
106
281 80
UG Terminations 87
188
184
133 75
Transformer 61
183 33
122 16
Switchgear 25 76 45 8
Secondary and Services 10 7 18 42 13
Regulator 15 12
Recloser
169
191
178
174
130
Primary Feeder 34 91 63 44 50
Pothead 4 6
Meter CT - Primary
Manhole 5
Insulator
248
215
152
173
Fused Cutout
199
329
362
284
211
Disconnect Switch 86 68 58 65
Capacitor Oil Switch 26 27 48 21 22
Capacitor
459
707
525
451
336
Arrester
139
230
212
138
Air Break Switch
ATO
2006 Total
2005 Total
2004 Total
2003 Total
2002 Total
Equipment
Infrared Inspection Items

29. History - Identified “Anomalies” by Device (Cont.)
4/22/2017
History - Identified “Anomalies” by Device (Cont.)

30. History - 2006 Identified “Anomalies”
4/22/2017
History Identified “Anomalies”

31. History - 2005 Identified “Anomalies”
4/22/2017
History Identified “Anomalies”

32. 4/22/2017
Questions?