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

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.

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

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

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

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 1999 - 2001 EPRI Project

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

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

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

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)

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

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

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

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

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

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

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

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

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 – 212.5 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 5-11-05 AND EQUIPMENT FAILED 7-23-05

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 6-8-05 AND EQUIPMENT FAILED 7-14-05

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 6-27-05 AND EQUIPMENT FAILED 7-4-05

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

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

4/22/2017 Examples (Cont.) Temperature of Hot Spot – 142.5 degrees C – H squeeze connection Temperature of White Arrow Spot – 33.6 degrees C – reference H squeeze connection Delta T temperature – 108.9 degrees C – rise above reference

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

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

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

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

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

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

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

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

4/22/2017 Questions?