TESCO Tuesday: Meter Testing in the Field
- 1. Slide 1 Today’s session will begin shortly @tescometering @TESCO_Metering TESCO -The Eastern Specialty Company TESCO -The Eastern Specialty Company TESCO Tuesdays
- 2. Slide 2 10/02/2012 Slide 2 Meter Testing in the Field Prepared by John H Carroll, BSEE TESCO Western Regional Sales Manager. The Eastern Specialty Company Tuesday, February 23, 2021
- 3. Slide 3 Topics we will be covering • Test Switches and CT’s • Meter Accuracy Testing Using MTS 3050 True 3 Phase • Customer Load Test-Video • Customer CT Ratio Test-Video • Phantom Load Test-Video • Q&A Discussions
- 4. Slide 4 Transformer Rated Metering • Meter measures scaled down representation of the load. • Scaling is accomplished by the use of external current transformers (CTs) and sometimes voltage transformers or PTs). • The meter is NOT part of the circuit • When the meter is removed from the socket, power to the customer is not effected.
- 5. Slide 5 9S Meter Installation with 400:5 CT’s 400A 400A 400A LOAD 5A 5A 5A SOURCE PHASE A PHASE B PHASE C The Basic Components
- 6. Slide 6 TESCO/Georgia Power 2017 Caribbean Meter School Fundamentals of Polyphase Field Meter Testing and Site Verification Full Load Light Load Power Factor Meter Accuracy Testing Meter Accuracy Testing Customer Load Customer Load Customer Billing Customer Conditions Meter Accuracy Testing Phantom Load
- 7. Slide 7 The Importance of CT Testing in the Field • One transformer in three wired backwards will give the customer a bill of 1/3rd the actual bill. • One broken wire to a single transformer will give the customer a bill of 2/3rd the actual bill • One dual ratio transformer inappropriately marked in the billing system as 400:5 instead of 800:5 provides a bill that is ½ of the actual bill. And the inverse will give a bill double of what should have been sent. Both are lose-lose situations for the utility.
- 8. Slide 8 The Importance of CT Testing in the Field (continued) • Cross Phasing (wiring errors) • Loose or Corroded Connections • CT Mounted Backwards • CT’s with Shorted Turns • Wrong Selection of Dual Ratio CT • Detect Magnetized CT’s • Burden Failure in Secondary Circuit • Open or Shorted Secondary • Mislabeled CT’s • Ensures all Shorting Blocks have been Removed
- 9. Slide 9 Meter Accuracy Testing Meter Accuracy Test using IR Pulse Detection Make connections from Field Tester to Meter Form Connect IR Pulse Detector to meter output Check pulse indictor Pulse Align if necessary Courtesy of APS
- 10. Slide 10 Meter Accuracy Testing Meter Accuracy Test using IR Pulse Detection Make connections from Field Tester to Meter Form Connect IR Pulse Detector to meter output Check pulse indictor Pulse Align if necessary
- 11. Slide 11 Customer Load Test -Video Meter Accuracy Test using IR Pulse Detection Make connections from Field Tester to Meter Form Connect IR Pulse Detector to meter output Check pulse indictor Pulse Align if necessary https://youtu.be/Miq3trNaPPc
- 12. Slide 12 Customer CT Ratio Test Make Connections from Field Tester to Primary current phases Make connections from Field Tester to Secondary test switch Connect IR Pulse Detector to meter output Courtesy of APS
- 13. Slide 13 Ratio of Primary Current to Secondary Current PHASE A SOURCE LOAD 400A 400A 400A 5A 5A Calculate Ratio Customer CT Ratio Test 80:1
- 14. Slide 14 Customer CT Ratio Test -Video Make Connections from Field Tester to Primary current phases Make connections from Field Tester to Secondary test switch Connect IR Pulse Detector to meter output https://youtu.be/JlHM-4mzuTs
- 15. Slide 15 Fundamentals of Polyphase Field Meter Testing and Site Verification Functionality with Burden Present on the Secondary Loop Example Burden Spec: 0.3% @ B0.1, B0.2, B0.5 or There should be less than the 0.3% change in secondary current from initial (“0” burden) reading, when up to 0.5 Ohms of burden is applied Customer CT Ratio Test with Burden
- 16. Slide 16 Customer CT Ratio Test with Burden Functionality with Burden Present on the Secondary Loop PHASE A • Some burden will always be present – junctions, meter coils, test switches, cables, etc. • CT’s must be able to maintain an accurate ratio with burden on the secondary.
- 17. Slide 17 Customer CT Test with Burden Functionality with Burden Present on the Secondary Loop 0.3% @ B0.1, B0.2, B0.5 0.0000 1.0000 2.0000 3.0000 4.0000 5.0000 6.0000 0 2 4 6 8 Initial Reading = 5Amps 0.3% x 5A = 0.015A 5A – 0.015 = 4.985A Burden Reading 0 5.0000 0.1 4.9999 0.2 4.9950 0.5 4.9900 1 4.9800 2 4.9500 4 4.0000 8 0.8000
- 18. Slide 18 CT Ratio Testing with Burden Added Meter Accuracy Test using IR Pulse Detection Make connections from Field Tester to Meter Form Connect IR Pulse Detector to meter output Check pulse indictor Pulse Align if necessary
- 19. Slide 19 Customer CT Test with Burden-Video Make Connections from Field Tester to Primary current phases Make connections from Field Tester to Secondary test switch Ensure additional burden value is selected Connect IR Pulse Detector to meter output https://youtu.be/d6PV3ZtWjPQ
- 20. Slide 20 Phantom Load Testing Determine the TA ( Test Amps) from Meter Faceplate Ensure Safety shorting switch and test jack have been disengaged Make connections from Field Tester to Meter Form using jumper EZ Clips. Connect IR Pulse Detector to meter output Check pulse indictor Pulse Align if necessary Courtesy of APS
- 21. Slide 21 Phantom Load Testing Determine the TA ( Test Amps) from Meter Faceplate Ensure Safety shorting switch and test jack have been disengaged Make connections from Field Tester to Meter Form using jumper EZ Clips. Connect IR Pulse Detector to meter output Check pulse indictor Pulse Align if necessary
- 22. Slide 22 Phantom Load Testing Determine the TA ( Test Amps) from Meter Faceplate Ensure Safety shorting switch and test jack have been disengaged Make connections from Field Tester to Meter Form using jumper EZ Clips. Connect IR Pulse Detector to meter output Check pulse indictor Pulse Align if necessary
- 23. Slide 23 Phantom Load Testing
- 24. Slide 24 Phantom Load Testing-Video Ensure Test Switch CT’s are shunted Make connections from Field Tester to Secondary test switch Connect EZ Clips to test switch Connect IR Pulse Detector to meter output https://youtu.be/Hdyn-KWOXaA
- 25. Slide 25 Harmonics Testing Harmonics are integer frequencies often found with non linear loads. THD=Total Harmonic Distortion Vthd <5%
- 26. Slide 26 Harmonics Testing-Waveforms Harmonics are generated as a voltage or current at an integer frequency of the system, produced by the action of non-linear loads such as rectifiers, discharge lighting, or switch mode power supplies. Harmonic frequencies in the power grid are a frequent cause of power quality problems.
- 27. Slide 27 Harmonics Testing-Waveforms What is the problem with Harmonics? HEAT. Can cause significant damage Safety Hazard Poor Power Factor AMI Mesh Interference Transformer Overheating Loss of service Image courtesy of irinfo.org
- 28. Slide 28 Harmonics Testing-Waveforms Can we reduce or eliminate Harmonics? Perhaps not eliminate. But we can reduce their impact. We live in non linear world of power where harmonics are generated. PWM conversion and AC Frequency Drive Motors and Pumps. Many thousands of todays electrical products have SWPS devices.
- 29. Slide 29 Harmonics Testing-Waveforms How can we reduce the impact of harmonics ? Measure and determine major harmonic condition under customer load. Assess most significant even & odd harmonics. Active Harmonic Filtering can reduce most significant index. Power Factor Correction Capacitor.
- 30. Slide 30 Periodic Site Inspections….. ….Can Discover or Prevent: • Billing Errors • Bad Metering set-up • Detect Current Diversion • Identify Potential Safety Issues • Metering Issues (issues not related to meter accuracy) • AMR/AMI Communications Issues • The need for Unscheduled Truck Rolls due to Undetected Field Related Issues • Discrepancies between what is believed to be at a given site versus the actual setup and equipment at the site
- 31. Slide 31 Questions and Discussion Thank you for Attending. John H Carroll Western Regional Manager john.carroll@tescometering.com TESCO – The Eastern Specialty Company Arizona Regional Office 480-467-7998
- 32. Slide 32 Thanks for tuning in! See you at the next session. Upcoming Session: Metering Configurations February 2, 2021 | 11:00 AM Eastern **TESCO Users Group: July 18-21, 2021** Presentation Date Transformer-Rated Testing Using Pickups and Probes 3/2 Traditional Ratio, Burden, Admittance and Demag Testing – Part 1 3/9 Traditional Ratio, Burden, Admittance and Demag Testing – Part 2 3/16 Realizing Your Investment in Technology Through Analytics 3/23 Shop Testing 3/30 Preparing for AMI Deployment 4/6 Communication Equipment 4/13 Sign up: tescometering.com/tesco-tuesdays